I'm using a webview2-control in a winforms application. I use messages to communicate between c# and Javascript
window.chrome.webview.addEventListener / window.chrome.webview.postMessage in Javascript
event .CoreWebView2.WebMessageReceived and method CoreWebView2.PostWebMessageAsString in C#
The communication works BUT only after the page in webview2 has been somehow refreshed. The first message sent by c# is always ignored/not received by JS. The messages after that are correcly received and processed.
My UI code:
public GUI()
{
InitializeComponent();
browser.Source = new Uri(System.IO.Path.GetFullPath("HTML/ui.html"));
InitializeAsync();
}
async void InitializeAsync()
{
await browser.EnsureCoreWebView2Async(null);
browser.CoreWebView2.WebMessageReceived += MessageReceived;
}
void MessageReceived(object sender, CoreWebView2WebMessageReceivedEventArgs args)
{
String content = args.TryGetWebMessageAsString();
if (content.StartsWith("getData"))
{
ReadDataFromCATIA();
var serializerSettings = new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.Objects };
string jsonRootNode = JsonConvert.SerializeObject(this.RootNode, Formatting.Indented, serializerSettings); //here I've got the message I want to post
//String input = args.TryGetWebMessageAsString();
//MessageBox.Show("string from JS: " + input);
browser.CoreWebView2.PostWebMessageAsString(jsonRootNode);
}
else //object received
{
ProductNode received = JsonConvert.DeserializeObject<ProductNode>(content);
MessageBox.Show(received.PartNumber + " received");
}
}
and my JS in ui.html
window.chrome.webview.addEventListener('message', event => {
alert(event.data);
WriteDataFromCsharp(event.data);
});
function WriteDataFromCsharp(data) {
var target = document.getElementById('target');
if (target === null) { alert('target not found') };
//alert(target.id);
//target.textContent = event.data;
rootNode = JSON.parse(data);
target.innerHTML = addTable(rootNode); //addTable create an HTML table from the deserialized object rootNode
}
function RequestData() {
//function triggered by a button on the html page
//alert('post to c#');
window.chrome.webview.postMessage('getData');
}
So far, i've tried to:
ensure the javascript is as late as possible in the page (defer, at the end of body). No changes.
inject the javascript to the page after it has been loaded using .CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync(jsCode). Same behavior.
inject the javascript after once the event NavigationCompleted has fired. same behavior.
What do I miss ?
Finally found the culprit: in my HTML-page, i've used a "submit" instead of "button". With
<input type="button" value="Load data from V5" onclick="RequestData()" />
The page behavior is as expected.
With the below html file, that gets loaded into the document of a winform webBrowser, the functions and events in the scripts do not fire. When the winform displays, it only shows the button with id=paybutton (see form definition). It does not run the 1st script (window.YocoSDK etc) which references an online sdk (as in the src), and which adds a few more fields onto the form. This works in an online java test but not via c# winforms. Can anyone assist.
Secondly, the ShowMessage() function also does not fire on clicking the button.
My guess with both is that the inclusion of the online sdk in the "src" field is not happening.
HTMLPageSample.html file:
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript' src='https://js.yoco.com/sdk/v1/yoco-sdk-web.js'></script>
</head>
<body>
<form id='payform' method='POST' >
<div class='one-liner'>
<div id='card-frame'>
</div>
<button id='paybutton' onclick='ShowMessage()'>
PAY ZAR 2.00
</button>
</div>
<p class='success-payment-message' />
</form>
<script>
var sdk = new window.YocoSDK({
publicKey: 'pk_test_blahblah'
});
var inline = sdk.inline({
layout: 'field',
amountInCents: 2000,
currency: 'ZAR'
});
inline.mount('#card-frame');
</script>
<script>
function ShowMessage() {
var form = document.getElementById('payform');
var submitButton = document.getElementById('paybutton');
form.addEventListener('submit', function (event) {
event.preventDefault()
submitButton.disabled = true;
inline.createToken().then(function (result) {
submitButton.disabled = false;
if (result.error) {
const errorMessage = result.error.message;
errorMessage && alert('error occured: ' + errorMessage);
} else {
const token = result;
alert('card successfully tokenised: ' + token.id);
}
}).catch(function (error) {
submitButton.disabled = false;
alert('error occured: ' + error);
});
});
};
</script>
</body>
</html>
//c# code for the windows form
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace WindowsFormsApp1
{
[System.Runtime.InteropServices.ComVisibleAttribute(true)]
public partial class Form1 : Form
{
//Class example
//[ComVisible(true)]
public Form1()
{
InitializeComponent();
webBrowser1.ScriptErrorsSuppressed = true;
}
void Form1_Load(object sender, EventArgs e)
{
string path = System.IO.Path.Combine(System.IO.Directory.GetCurrentDirectory(), #"..\..\");
//load the html into the webbrowser document. only the paybutton displays, the referenced library in "src" should call an online sdk that adds the payment fields to the form. these fields do not get added. so it seems the src reference is not working, or the script and form definitions cannot "see" each other?
webBrowser1.Navigate(System.IO.Path.Combine(path, "HTMLPageSample.html"));
}
void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
webBrowser1.ObjectForScripting = this;
}
private void button1_Click(object sender, EventArgs e)
{
//on button click, invoke the script that processes payment (does nothing)
webBrowser1.Document.InvokeScript("ShowMessage" );
}
private void button2_Click(object sender, EventArgs e)
{
//on button click, locate paybutton and invoke click method (does nothing)
foreach (HtmlElement element in webBrowser1.Document.All)
{
if (element.InnerText != null && element.InnerText.ToLower().StartsWith("pay zar"))
{
element.InvokeMember("click");
}
}
}
}
}
When using WebBrowser, it defaults to IE7, unless there is an entry in the registry.
If the process is running as 64-bit, the following registry keys are searched:
HKLM\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
HKCU\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
If the process is running as 32-bit, the following registry keys are searched:
HKLM\SOFTWARE\WOW6432Node\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
HKCU\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
Note: While different registry keys are searched in HKLM, when HKCU is searched, both 32-bit and 64-bit search the same subkey.
Here's a sample registry entry for a program named "MyApp.exe" that emulates IE11.
Below are step-by-step instructions that show how to run a JavaScript function when a button is clicked in C#. It uses a modified version of the HTML that's in the OP.
VS 2019:
Create a new project: Windows Forms App (.NET Framework) (name: WebBrowserTest)
Create a class (name: HelperRegistry.cs)
Note: The following code can be used to add the required entry in the registry when the Form loads. It's adapted from here.
HelperRegistry
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Win32;
using System.Diagnostics;
namespace WebBrowserTest
{
public enum BrowserEmulationVersion
{
Default = 0,
Version7 = 7000,
Version8 = 8000,
Version8Standards = 8888,
Version9 = 9000,
Version9Standards = 9999,
Version10 = 10000,
Version10Standards = 10001,
Version11 = 11000,
Version11Edge = 11001
};
public class HelperRegistry
{
public static BrowserEmulationVersion GetBrowserEmulationVersion()
{
//get browser emmulation version for this program (if it exists)
BrowserEmulationVersion result = BrowserEmulationVersion.Default;
try
{
string programName = System.IO.Path.GetFileName(Environment.GetCommandLineArgs()[0]);
object data = GetValueFromRegistry(RegistryHive.CurrentUser, #"Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION", programName);
if (data != null)
{
result = (BrowserEmulationVersion)Convert.ToInt32(data);
}
}
catch (System.Security.SecurityException ex)
{
// The user does not have the permissions required to read from the registry key.
LogMsg("Error: (GetBrowserEmulationVersion - SecurityException) - " + ex.Message);
}
catch (UnauthorizedAccessException ex)
{
// The user does not have the necessary registry rights.
LogMsg("Error: (GetBrowserEmulationVersion - UnauthorizedAccessException) - " + ex.Message);
}
catch (Exception ex)
{
LogMsg("Error: (GetBrowserEmulationVersion) - " + ex.Message);
}
return result;
}
public static int GetInternetExplorerMajorVersion()
{
//get IE version
int result = 0;
string version = string.Empty;
try
{
string programName = System.IO.Path.GetFileName(Environment.GetCommandLineArgs()[0]);
object data = GetValueFromRegistry(RegistryHive.LocalMachine, #"Software\Microsoft\Internet Explorer", "svcVersion");
if (data == null)
data = GetValueFromRegistry(RegistryHive.CurrentUser, #"Software\Microsoft\Internet Explorer", "Version");
if (data != null)
{
version = data.ToString();
int separator = version.IndexOf('.');
if (separator != -1)
{
int.TryParse(version.Substring(0, separator), out result);
}
}
}
catch (System.Security.SecurityException ex)
{
// The user does not have the permissions required to read from the registry key.
LogMsg("Error: (GetInternetExplorerMajorVersion - SecurityException) - " + ex.Message);
}
catch (UnauthorizedAccessException ex)
{
// The user does not have the necessary registry rights.
LogMsg("Error: (GetInternetExplorerMajorVersion - UnauthorizedAccessException) - " + ex.Message);
}
catch (Exception ex)
{
LogMsg("Error: (GetInternetExplorerMajorVersion) - " + ex.Message);
}
return result;
}
private static object GetValueFromRegistry(RegistryHive hive, string subkey, string regValue)
{
//if running as 64-bit, get value from 64-bit registry
//if running as 32-bit, get value from 32-bit registry
RegistryView rView = RegistryView.Registry64;
object data = null;
if (!Environment.Is64BitProcess)
{
//running as 32-bit
rView = RegistryView.Registry32;
}
using (RegistryKey regBaseKey = RegistryKey.OpenBaseKey(hive, rView))
{
using (RegistryKey sKey = regBaseKey.OpenSubKey(subkey))
{
if (sKey != null)
{
data = sKey.GetValue(regValue, null);
if (data != null)
{
LogMsg("data: " + data.ToString());
}
else
{
LogMsg("data is null (" + data + ")");
}
}
}
}
return data;
}
public static bool IsBrowserEmulationSet()
{
return GetBrowserEmulationVersion() != BrowserEmulationVersion.Default;
}
private static void LogMsg(string msg)
{
string logMsg = String.Format("{0} {1}", DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss:fff"), msg);
System.Diagnostics.Debug.WriteLine(logMsg);
}
public static bool SetBrowserEmulationVersion()
{
BrowserEmulationVersion emulationCode;
int ieVersion = GetInternetExplorerMajorVersion();
if (ieVersion >= 11)
{
emulationCode = BrowserEmulationVersion.Version11;
}
else
{
switch (ieVersion)
{
case 10:
emulationCode = BrowserEmulationVersion.Version10;
break;
case 9:
emulationCode = BrowserEmulationVersion.Version9;
break;
case 8:
emulationCode = BrowserEmulationVersion.Version8;
break;
default:
emulationCode = BrowserEmulationVersion.Version7;
break;
}
}
return SetBrowserEmulationVersion(emulationCode);
}
public static bool SetBrowserEmulationVersion(BrowserEmulationVersion browserEmulationVersion)
{
bool result = false;
//if running as 64-bit, get value from 64-bit registry
//if running as 32-bit, get value from 32-bit registry
RegistryView rView = RegistryView.Registry64;
if (!Environment.Is64BitProcess)
{
//running as 32-bit
rView = RegistryView.Registry32;
}
try
{
string programName = System.IO.Path.GetFileName(Environment.GetCommandLineArgs()[0]);
using (RegistryKey regBaseKey = RegistryKey.OpenBaseKey(RegistryHive.CurrentUser, rView))
{
using (RegistryKey sKey = regBaseKey.OpenSubKey(#"Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION", true))
{
if (sKey != null)
{
if (browserEmulationVersion != BrowserEmulationVersion.Default)
{
// if it's a valid value, update or create the value
sKey.SetValue(programName, (int)browserEmulationVersion, Microsoft.Win32.RegistryValueKind.DWord);
}
else
{
// otherwise, remove the existing value
sKey.DeleteValue(programName, false);
}
result = true;
}
}
}
}
catch (System.Security.SecurityException ex)
{
// The user does not have the permissions required to read from the registry key.
LogMsg("Error: (SetBrowserEmulationVersion - SecurityException) - " + ex.Message);
}
catch (UnauthorizedAccessException ex)
{
// The user does not have the necessary registry rights.
LogMsg("Error: (SetBrowserEmulationVersion - UnauthorizedAccessException) - " + ex.Message);
}
catch (Exception ex)
{
LogMsg("Error: (SetBrowserEmulationVersion) - " + ex.Message);
}
return result;
}
}
}
In the Form "Load" event handler add the following:
HelperRegistry.SetBrowserEmulationVersion();
If desired, the HTML can be embedded in the program.
Open Solution Explorer
In VS menu, click View
Select Solution Explorer
Open Properties Window
In VS menu, click View
Select Properties Window
Create HTML folder
In Solution Explorer, right-click <solution name>
Select Add
Select New Folder (rename to desired name; ex: HTML)
Right-click the folder you just created (ex: HTML) and select Add
Select New Item...
Select HTML Page (name: HTMLPageSample.html)
Click Add
Note: If you don't see "HTML Page" as an option, you'll need to open Visual Studio Installer and add a workload that includes HTML.
Set Properties for HTMLPageSample.html
In Solution Explorer, click HTMLPageSample.html
In the Properties Window, set Build Action = Embedded Resource
HTMLPageSample.html
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript' src='https://js.yoco.com/sdk/v1/yoco-sdk-web.js'></script>
<script type="text/javascript">
var sdk = new window.YocoSDK({
publicKey: 'pk_test_blahblah'
});
var inline = sdk.inline({
layout: 'field',
amountInCents: 2000,
currency: 'ZAR'
});
inline.mount('#card-frame');
</script>
<script type="text/javascript">
function ShowMessage() {
try {
//alert('in ShowMessage...');
var form = document.getElementById('payform');
var submitButton = document.getElementById('paybutton');
form.addEventListener('submit', function (event) {
event.preventDefault()
submitButton.disabled = true;
inline.createToken().then(function (result) {
submitButton.disabled = false;
if (result.error) {
const errorMessage = result.error.message;
errorMessage && alert('error occured: ' + errorMessage);
} else {
const token = result;
alert('card successfully tokenised: ' + token.id);
}
}).catch(function (error) {
submitButton.disabled = false;
alert('error occured: ' + error);
});
});
}
catch (err) {
alert(err.message);
}
};
</script>
</head>
<body>
<form id='payform' method='POST'>
<div class='one-liner'>
<div id='card-frame'>
</div>
<button id='paybutton' onclick='ShowMessage()'>
PAY ZAR 2.00
</button>
</div>
<p class='success-payment-message' />
</form>
</body>
</html>
Now, we'll need some code to read the embedded HTML file. We'll use code from here.
Create a class (name: HelperLoadResource.cs)
HelperLoadResource
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Reflection;
using System.Diagnostics;
namespace WebBrowserTest
{
public static class HelperLoadResource
{
public static string ReadResource(string filename)
{
//use UTF8 encoding as the default encoding
return ReadResource(filename, Encoding.UTF8);
}
public static string ReadResource(string filename, Encoding fileEncoding)
{
string fqResourceName = string.Empty;
string result = string.Empty;
//get executing assembly
Assembly execAssembly = Assembly.GetExecutingAssembly();
//get resource names
string[] resourceNames = execAssembly.GetManifestResourceNames();
if (resourceNames != null && resourceNames.Length > 0)
{
foreach (string rName in resourceNames)
{
if (rName.EndsWith(filename))
{
//set value to 1st match
//if the same filename exists in different folders,
//the filename can be specified as <folder name>.<filename>
//or <namespace>.<folder name>.<filename>
fqResourceName = rName;
//exit loop
break;
}
}
//if not found, throw exception
if (String.IsNullOrEmpty(fqResourceName))
{
throw new Exception($"Resource '{filename}' not found.");
}
//get file text
using (Stream s = execAssembly.GetManifestResourceStream(fqResourceName))
{
using (StreamReader reader = new StreamReader(s, fileEncoding))
{
//get text
result = reader.ReadToEnd();
}
}
}
return result;
}
}
}
Usage:
string html = HelperLoadResource.ReadResource("HTMLPageSample.html");
Next, we'll work on our Form (name: Form1).
In Solution Explorer, right-click Form1.cs
Select View Designer
Open the Toolbox
In the VS menu, click View
Select Toolbox
Add WebBrowser to Form
In Toolbox, click on WebBrowser and drag it on top of the Form
Add Button to Form
In Toolbox, click on Button and drag it on top of the form
In the Properties Window, rename the button (name: btnSubmit)
Add Load event Handler to Form
In the Properties Window, click on
Double-click Load, to add the event handler
Whenever a page is loaded in the WebBrowser, either by using Navigate or by setting the DocumentText, it's important to wait until it is fully loaded. We'll create a method for the wait operation. I normally avoid using "DoEvents", but we'll use it this time.
private void WaitForBrowserToBeReady(int sleepTimeInMs = 125)
{
do
{
System.Threading.Thread.Sleep(sleepTimeInMs);
Application.DoEvents();
} while (webBrowser1.ReadyState != WebBrowserReadyState.Complete);
}
Now in Form1_Load, add the following code:
private void Form1_Load(object sender, EventArgs e)
{
//set browser emulation in registry
HelperRegistry.SetBrowserEmulationVersion();
//suppress script errors
webBrowser1.ScriptErrorsSuppressed = true;
//string path = System.IO.Path.Combine(System.IO.Directory.GetCurrentDirectory(), #"..\..\");
//load the html into the webbrowser document. only the paybutton displays, the referenced library in "src"
//should call an online sdk that adds the payment fields to the form. these fields do not get added. so
//it seems the src reference is not working, or the script and form definitions cannot "see" each other?
//webBrowser1.Navigate(System.IO.Path.Combine(path, "HTMLPageSample.html"));
string html = HelperLoadResource.ReadResource("HTMLPageSample.html");
if (Environment.Is64BitProcess)
{
Debug.WriteLine("Running as 64-bit");
}
else
{
Debug.WriteLine("Running as 32-bit");
}
//initialize WebBrowser
webBrowser1.Navigate("about:blank");
WaitForBrowserToBeReady();
//set HTML
webBrowser1.DocumentText = html;
WaitForBrowserToBeReady();
//Debug.WriteLine(webBrowser1.DocumentText);
}
As stated in the OP, when the button is click it's desired that the ShowMessage() javascript function be called. Due to the way the JavaScript function is written, we'll do the following:
HtmlElementCollection col = webBrowser1.Document.GetElementsByTagName("button");
foreach (HtmlElement element in col)
{
if (element.GetAttribute("id").Equals("paybutton"))
{
element.InvokeMember("click"); // Invoke the "Click" member of the button
}
}
Note: While the following will also call ShowMessage(),
object result = webBrowser1.Document.InvokeScript("ShowMessage");
it won't give the desired result due to form.addEventListener('submit'... which requires a "click".
Here's the full code for Form1.cs.
Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Microsoft.Web.WebView2.Core;
using Microsoft.Web.WebView2.WinForms;
using System.Security.Permissions;
using System.Runtime.InteropServices;
using System.Diagnostics;
namespace WebBrowserTest
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
//set browser emulation in registry
HelperRegistry.SetBrowserEmulationVersion();
//suppress script errors
webBrowser1.ScriptErrorsSuppressed = true;
//string path = System.IO.Path.Combine(System.IO.Directory.GetCurrentDirectory(), #"..\..\");
//load the html into the webbrowser document. only the paybutton displays, the referenced library in "src"
//should call an online sdk that adds the payment fields to the form. these fields do not get added. so
//it seems the src reference is not working, or the script and form definitions cannot "see" each other?
//webBrowser1.Navigate(System.IO.Path.Combine(path, "HTMLPageSample.html"));
string html = HelperLoadResource.ReadResource("HTMLPageSample.html");
if (Environment.Is64BitProcess)
{
Debug.WriteLine("Running as 64-bit");
}
else
{
Debug.WriteLine("Running as 32-bit");
}
//initialize WebBrowser
webBrowser1.Navigate("about:blank");
WaitForBrowserToBeReady();
//set HTML
webBrowser1.DocumentText = html;
WaitForBrowserToBeReady();
//Debug.WriteLine(webBrowser1.DocumentText);
}
private void LogMsg(string msg)
{
string logMsg = String.Format("{0} {1}", DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss:fff"), msg);
System.Diagnostics.Debug.WriteLine(logMsg);
}
private void btnSubmit_Click(object sender, EventArgs e)
{
//object result = webBrowser1.Document.InvokeScript("ShowMessage", null);
//object result = webBrowser1.Document.InvokeScript("ShowMessage");
HtmlElementCollection col = webBrowser1.Document.GetElementsByTagName("button");
foreach (HtmlElement element in col)
{
if (element.GetAttribute("id").Equals("paybutton"))
{
element.InvokeMember("click"); // Invoke the "Click" member of the button
}
}
}
private void WaitForBrowserToBeReady(int sleepTimeInMs = 125)
{
do
{
System.Threading.Thread.Sleep(sleepTimeInMs);
Application.DoEvents();
} while (webBrowser1.ReadyState != WebBrowserReadyState.Complete);
}
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
}
}
}
Resources:
How to Click A Button Programmatically - Button in WebBrowser (IE)
Calling JavaScript functions in the Web Browser Control
Execute a JS function in WebBrowser C#
Configuring the Emulation Mode of an Internet Explorer WebBrowser Control
How to read embedded resource text file
C# WebBrowser control: window.external access sub object
Here's a version that uses WebView2. Below are step-by-step instructions that show how to run a JavaScript function when a button is clicked in C#. It uses a modified version of the HTML that's in the OP.
VS 2019:
Create a new project: Windows Forms App (.NET Framework) (name: WebView2SM)
If desired, the HTML can be embedded in the program.
Open Solution Explorer
In VS menu, click View
Select Solution Explorer
Open Properties Window
In VS menu, click View
Select Properties Window
Create HTML folder
In Solution Explorer, right-click <solution name>
Select Add
Select New Folder (rename to desired name; ex: HTML)
Right-click the folder you just created (ex: HTML) and select Add
Select New Item...
Select HTML Page (name: HTMLPageSample.html)
Click Add
Note: If you don't see "HTML Page" as an option, you'll need to open Visual Studio Installer and add a workload that includes HTML.
Set Properties for HTMLPageSample.html
In Solution Explorer, click HTMLPageSample.html
In the Properties Window, set Build Action = Embedded Resource
HTMLPageSample.html
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript' src='https://js.yoco.com/sdk/v1/yoco-sdk-web.js'></script>
<script type="text/javascript">
var sdk = new window.YocoSDK({
publicKey: 'pk_test_blahblah'
});
var inline = sdk.inline({
layout: 'field',
amountInCents: 2000,
currency: 'ZAR'
});
inline.mount('#card-frame');
</script>
<script type="text/javascript">
function ShowMessage() {
try {
//alert('in ShowMessage...');
var form = document.getElementById('payform');
var submitButton = document.getElementById('paybutton');
form.addEventListener('submit', function (event) {
event.preventDefault()
submitButton.disabled = true;
inline.createToken().then(function (result) {
submitButton.disabled = false;
if (result.error) {
const errorMessage = result.error.message;
errorMessage && alert('error occured: ' + errorMessage);
} else {
const token = result;
alert('card successfully tokenised: ' + token.id);
}
}).catch(function (error) {
submitButton.disabled = false;
alert('error occured: ' + error);
});
});
}
catch (err) {
alert(err.message);
}
};
</script>
</head>
<body>
<form id='payform' method='POST'>
<div class='one-liner'>
<div id='card-frame'>
</div>
<button id='paybutton' onclick='ShowMessage()'>
PAY ZAR 2.00
</button>
</div>
<p class='success-payment-message' />
</form>
</body>
</html>
Now, we'll need some code to read the embedded HTML file. We'll use code from here.
Create a class (name: HelperLoadResource.cs)
HelperLoadResource
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Reflection;
using System.Diagnostics;
namespace WebView2SM
{
public static class HelperLoadResource
{
public static string ReadResource(string filename)
{
//use UTF8 encoding as the default encoding
return ReadResource(filename, Encoding.UTF8);
}
public static string ReadResource(string filename, Encoding fileEncoding)
{
string fqResourceName = string.Empty;
string result = string.Empty;
//get executing assembly
Assembly execAssembly = Assembly.GetExecutingAssembly();
//get resource names
string[] resourceNames = execAssembly.GetManifestResourceNames();
if (resourceNames != null && resourceNames.Length > 0)
{
foreach (string rName in resourceNames)
{
if (rName.EndsWith(filename))
{
//set value to 1st match
//if the same filename exists in different folders,
//the filename can be specified as <folder name>.<filename>
//or <namespace>.<folder name>.<filename>
fqResourceName = rName;
//exit loop
break;
}
}
//if not found, throw exception
if (String.IsNullOrEmpty(fqResourceName))
{
throw new Exception($"Resource '{filename}' not found.");
}
//get file text
using (Stream s = execAssembly.GetManifestResourceStream(fqResourceName))
{
using (StreamReader reader = new StreamReader(s, fileEncoding))
{
//get text
result = reader.ReadToEnd();
}
}
}
return result;
}
}
}
Usage:
string html = HelperLoadResource.ReadResource("HTMLPageSample.html");
Change/Verify NuGet Package Manager Settings (optional for .NET Framework; required for .NET)
In VS menu, click Tools
Select Options
Double-click NuGet Package Manager
Under "Package Management", set Default package management format: PackageReference
Click OK
See the following for more information:
Package references (PackageReference) in project files
Migrate from packages.config to PackageReference
Add WebView2 NuGet package
In Solution Explorer, right-click <solution name> (ex: WebView2SM)
Select Manage NuGet packages...
Click Browse
Optional: check Include prerelease box next to the search box
In search box, type: Microsoft.Web.WebView2
Select the desired version
Click Install
If you see a pop-up, click OK
Note: To add WebView2 to just the project, instead of the solution, right-click <project name> instead of <solution name>.
Next, we'll work on our Form (name: Form1).
In Solution Explorer, right-click Form1.cs
Select View Designer
Open the Toolbox
In the VS menu, click View
Select Toolbox
Add WebView2 to Form
In Toolbox, click on WebView2 Windows Control Form to expand it
Click on WebView2 and drag it on top of the Form
Resize the WebView2 control as desired
Add Button to Form
In Toolbox, click on Button and drag it on top of the form
In the Properties Window, rename the button (name: btnSubmit)
In the Properties Window, click
Double-click Click, to add the event handler
Add Load event Handler to Form
In the Properties Window, click
Double-click Load, to add the event handler
Add CoreWebView2InitializationCompleted event handler
In Solution Explorer, right-click Form1.cs
Select View Designer
In Properties Window, click
Click on the drop-down and select the WebView2 control (ex: webView21)
Double-click CoreWebView2InitializationCompleted
Optional: double-click NavigationCompleted (repeat for any other desired event handlers)
Now, it's we'll work on the code for the Form.
In Solution Explorer, right-click Form1.cs
Select View Code
For testing, we'll add a method named LogMsg.
private void LogMsg(string msg)
{
string logMsg = String.Format("{0} {1}", DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss:fff"), msg);
System.Diagnostics.Debug.WriteLine(logMsg);
}
This method can be modified as desired. If desired, one could write the information to a log file. If you already have a method for logging, you can use that instead. I've included this one, because it's used in the code.
In order to set the desired location for the web cache that will be created, we'll explicitly initialize WebView2. We'll call it InitializeCoreWebView2Async. We'll also create a method that can be used to add code using AddScriptToExecuteOnDocumentCreatedAsync.
Note: It's necessary to use async when using await. Notice the use of Task instead of void. If void is used, execution will continue without waiting.
AddScriptToExecuteOnDocumentCreatedAsync
private async Task AddExecuteOnDocumentCreatedAsyncCode()
{
if (webView21 != null && webView21.CoreWebView2 != null)
{
string jsCode = string.Empty;
//ToDo: add desired code using 'AddScriptToExecuteOnDocumentCreatedAsync'
if (!String.IsNullOrEmpty(jsCode))
{
await webView21.CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync(jsCode);
}
}
}
InitializeCoreWebView2Async
public async Task InitializeCoreWebView2Async(WebView2 wv, string webCacheDir = "")
{
CoreWebView2EnvironmentOptions options = null;
string tempWebCacheDir = string.Empty;
CoreWebView2Environment webView2Environment = null;
//set value
tempWebCacheDir = webCacheDir;
if (String.IsNullOrEmpty(tempWebCacheDir))
{
//use temp folder
//get fully-qualified path to user's temp folder
tempWebCacheDir = System.IO.Path.GetTempPath();
//create a randomly named folder - this will create a new web cache folder each time
//creating a new web cache folder takes time. By re-using an existing web cache,
//the load time will be shorter. However, one may need to manage (clean-up)
//objects in the web cache that are no longer needed
//tempWebCacheDir = System.IO.Path.Combine(tempWebCacheDir, System.Guid.NewGuid().ToString("N"));
}
//webView2Environment = await CoreWebView2Environment.CreateAsync(#"C:\Program Files (x86)\Microsoft\Edge Dev\Application\1.0.902.49", tempWebCacheDir, options);
webView2Environment = await CoreWebView2Environment.CreateAsync(null, tempWebCacheDir, options);
//wait for CoreWebView2 initialization
await wv.EnsureCoreWebView2Async(webView2Environment);
//add desired code using AddScriptToExecuteOnDocumentCreatedAsync
await AddExecuteOnDocumentCreatedAsyncCode();
LogMsg("Info: Cache data folder set to: " + tempWebCacheDir);
}
Usage:
await InitializeCoreWebView2Async(webView21);
Now in Form1_Load, add the following code:
private async void Form1_Load(object sender, EventArgs e)
{
//initialize
await InitializeCoreWebView2Async(webView21);
string html = HelperLoadResource.ReadResource("HTMLPageSample.html");
webView21.NavigateToString(html);
}
Once WebView2 initialization is completed, we'll add any desired event handlers for CoreWebView2. We'll add them in CoreWebView2InitializationCompleted.
private void webView21_CoreWebView2InitializationCompleted(object sender, Microsoft.Web.WebView2.Core.CoreWebView2InitializationCompletedEventArgs e)
{
//subscribe to events (add event handlers)
webView21.CoreWebView2.DOMContentLoaded += CoreWebView2_DOMContentLoaded;
}
Note: Don't place any code in the event handler that could cause "blocking".
As stated in the OP, when the button is click it's desired that the ShowMessage() javascript function be called. Due to the way the JavaScript function is written, we'll do the following:
var result = await webView21.CoreWebView2.ExecuteScriptAsync("document.getElementById('paybutton').click();");
Note: While the following will also call ShowMessage(),
var result = await webView21.CoreWebView2.ExecuteScriptAsync("ShowMessage();");
it won't give the desired result due to form.addEventListener('submit'... which requires a "click".
Here's the full code for Form1.cs.
Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Microsoft.Web.WebView2.Core;
using Microsoft.Web.WebView2.WinForms;
namespace WebView2SM
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private async void Form1_Load(object sender, EventArgs e)
{
//initialize
await InitializeCoreWebView2Async(webView21);
string html = HelperLoadResource.ReadResource("HTMLPageSample.html");
webView21.NavigateToString(html);
}
private async Task AddExecuteOnDocumentCreatedAsyncCode()
{
if (webView21 != null && webView21.CoreWebView2 != null)
{
string jsCode = string.Empty;
//ToDo: add desired code using 'AddScriptToExecuteOnDocumentCreatedAsync'
if (!String.IsNullOrEmpty(jsCode))
{
await webView21.CoreWebView2.AddScriptToExecuteOnDocumentCreatedAsync(jsCode);
}
}
}
private async Task InitializeCoreWebView2Async()
{
//initialize CorewWebView2
await webView21.EnsureCoreWebView2Async();
//add desired code using AddScriptToExecuteOnDocumentCreatedAsync
await AddExecuteOnDocumentCreatedAsyncCode();
}
public async Task InitializeCoreWebView2Async(WebView2 wv, string webCacheDir = "")
{
CoreWebView2EnvironmentOptions options = null;
string tempWebCacheDir = string.Empty;
CoreWebView2Environment webView2Environment = null;
//set value
tempWebCacheDir = webCacheDir;
if (String.IsNullOrEmpty(tempWebCacheDir))
{
//use temp folder
//get fully-qualified path to user's temp folder
tempWebCacheDir = System.IO.Path.GetTempPath();
//create a randomly named folder - this will create a new web cache folder each time
//creating a new web cache folder takes time. By re-using an existing web cache,
//the load time will be shorter. However, one may need to manage (clean-up)
//objects in the web cache that are no longer needed
//tempWebCacheDir = System.IO.Path.Combine(tempWebCacheDir, System.Guid.NewGuid().ToString("N"));
}
//webView2Environment = await CoreWebView2Environment.CreateAsync(#"C:\Program Files (x86)\Microsoft\Edge Dev\Application\1.0.902.49", tempWebCacheDir, options);
webView2Environment = await CoreWebView2Environment.CreateAsync(null, tempWebCacheDir, options);
//wait for CoreWebView2 initialization
await wv.EnsureCoreWebView2Async(webView2Environment);
//add desired code using AddScriptToExecuteOnDocumentCreatedAsync
await AddExecuteOnDocumentCreatedAsyncCode();
LogMsg("Info: Cache data folder set to: " + tempWebCacheDir);
}
private void LogMsg(string msg)
{
string logMsg = String.Format("{0} {1}", DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss:fff"), msg);
System.Diagnostics.Debug.WriteLine(logMsg);
}
private void webView21_CoreWebView2InitializationCompleted(object sender, Microsoft.Web.WebView2.Core.CoreWebView2InitializationCompletedEventArgs e)
{
//subscribe to events (add event handlers)
webView21.CoreWebView2.DOMContentLoaded += CoreWebView2_DOMContentLoaded;
}
private void CoreWebView2_DOMContentLoaded(object sender, Microsoft.Web.WebView2.Core.CoreWebView2DOMContentLoadedEventArgs e)
{
}
private void webView21_NavigationCompleted(object sender, Microsoft.Web.WebView2.Core.CoreWebView2NavigationCompletedEventArgs e)
{
}
private async void btnSubmit_Click(object sender, EventArgs e)
{
//var result = await webView21.CoreWebView2.ExecuteScriptAsync("ShowMessage();");
var result = await webView21.CoreWebView2.ExecuteScriptAsync("document.getElementById('paybutton').click();");
}
}
}
Resources
Introduction to Microsoft Edge WebView2
Release notes for WebView2 SDK
Understand WebView2 SDK versions
Report An Issue With WebView2
Distribution of apps using WebView2
Get started with WebView2 in Windows Forms
Download the WebView2 Runtime
What is .NET Framework?
Introduction to .NET
.NET Core/5+ vs. .NET Framework for server apps
I have the following case where a user has selected a product, the product record has been retrieved and the backorder flag is set. I want to ask the user if the want to include it in the order anyway. I can't seem to find an exaample anywhere that demonstrates it in an IF statement.
My VB Code Snippet:
Dim backorder = myDataTable.Rows(0)("backorder").ToString()
If backorder = "True" And <somehow ask user it they want to order anyway> Then
'do something
End If
My Javascript in aspx file:
<script type = "text/javascript">
function Confirm() {
var confirm_value = document.createElement("INPUT");
confirm_value.type = "hidden";
confirm_value.name = "confirm_value";
if (confirm("Selected item is on temporary back order. Do yuou want to include it on this order?")) {
confirm_value.value = "Yes";
} else {
confirm_value.value = "No";
}
document.forms[0].appendChild(confirm_value);
}
</script>
I can read the variable being added, by javascript, to the page from VB, but can't figure how to call the javascript in order to prompt the user.
For some reason I can't get my head around this. Please advise with example.
Use the RegisterStartupScript method:
Sub ProcessOrder()
'Your code to process the selected products here...
Dim orderAnyway As string = hdnConfirmResponse.Value.Trim()
If selectedItem.BackOrdered Then
If orderAnyway = "" Then
Dim cs As ClientScriptManager = Page.ClientScript
' Define the name and type of the client scripts on the page.
Dim csname1 As String = "ConfirmScript"
Dim cstype As Type = Me.GetType()
' Check to see if the startup script is already registered.
If (Not cs.IsStartupScriptRegistered(cstype, csname1)) Then
Dim cstext1 As String = "Confirm();"
cs.RegisterStartupScript(cstype, csname1, cstext1, True)
End If
Else
If orderAnyway = "yes" Then
'ADD THE BACKORDERED ITEM SINCE THEY CONFIRMED
End If
End If
End If
End Sub
I hate answering my own question but this what finally worked. Mixture of mjw's answer and more research on my javasvript attempt. Rather than have JS create the hidden field, I added it to the HTML
<asp:HiddenField runat="server" id ="confirm_value"/>
New VB:
If myDataTableFrame.Rows.Count > 0 Then
Dim backorder = myDataTableFrame.Rows(0)("backorder").ToString()
If backorder = "True" And confirm_value.Value <> "Yes" Then
Dim cs As ClientScriptManager = Page.ClientScript
' Check to see if the startup script is already registered.
If (Not cs.IsStartupScriptRegistered(Me.GetType(), "ConfirmScript")) Then
Dim cstext1 As String = "Confirm();"
cs.RegisterStartupScript(Me.GetType(), "ConfirmScript", "Confirm();", True)
End If
Return
Else
confirm_value.Value = "No"
...
New Javascript:
See ASP.NET set hiddenfield a value in Javascript Also added a reclick of the button if they answered "OK"
<script type = "text/javascript">
function Confirm() {
if (confirm("Selected item is on temporary back order. If you want to include it on this order click OK, then resubmit it?")) {
//had to resort to this to find hidden field rather than document.getElementById('confirm_value')
var x = document.getElementById('<%= confirm_value.ClientID%>');
x.value = 'Yes';
//re-click the button
document.getElementById('<%=bttnadd.ClientID%>').click();
} else {
var x = document.getElementById('<%= confirm_value.ClientID%>');
x.value = 'No';
}
}
</script>
i am developing uwp app (win 10) by c#
i want put my website in xaml webview element.
most of function are workable.
but i can't handle the confirm dialog
for example
this is sample html & js code
<button id="btnConfirm" onclick="confirmBox('sure to delete?')">click me to confirm</button>
<button id="btnAlert" onclick="alert('alert message')">click me to alert</button>
<script type="text/javascript">
function confirmBox(message) {
if (confirm(message)) {
alert("yes");
} else {
alert("no");
}
}
</script>
this is my xaml code
<WebView Grid.Row="1" x:Name="webView1" Source="ms-appx-web:///HTMLPage1.html" Width="auto" Height="auto"/>
this is my C# code
webView1.ScriptNotify += webView1_ScriptNotify;
webView1.NavigationCompleted += webView1_NavigationCompleted;
async void webView1_NavigationCompleted(WebView sender, WebViewNavigationCompletedEventArgs args)
{
await webView1.InvokeScriptAsync("eval", new string[] { "window.confirm = function(confirmMessage) { window.external.notify('typeConfirm:' + confirmMessage) }" });
await webView1.InvokeScriptAsync("eval", new string[] { "window.alert = function(AlertMessage) { window.external.notify('typeAlert:' + AlertMessage) }" });
}
private async void webView1_ScriptNotify(object sender, NotifyEventArgs e)
{
Windows.UI.Popups.MessageDialog dialog;
string[] messageArray = e.Value.Split(':');
string message;
string type;
if (messageArray.Length > 1)
{
message = messageArray[1];
type = messageArray[0];
}
else
{
message = e.Value;
type = "typeAlert";
}
dialog = new Windows.UI.Popups.MessageDialog(message);
Debug.WriteLine("type=" + type + " ,message=" + message);
if (type.Equals("typeConfirm"))
{
dialog.Commands.Add(new UICommand(
"Yes",
new UICommandInvokedHandler(this.CommandInvokedHandler)));
dialog.Commands.Add(new UICommand(
"Cancel",
new UICommandInvokedHandler(this.CommandInvokedHandler)));
dialog.DefaultCommandIndex = 0;
dialog.CancelCommandIndex = 1;
}
var result = await dialog.ShowAsync();
if (result.Label.Equals("Yes"))
{
// return true;
}
else
{
// return false
}
}
the problem is that confirm js function will always return false
before user clicked the yes or no.
i can get user choosed button. but it's too late.
js function "confirm" will never return true in this situation.
anyone can help me?
thanks.
This will not work. JS runs on single thread, and will not wait for the result of the c# call. So the alert will not wait for the result from the MessageDialog.
Please note that webview in winrt project more suitable for displaying some static html. If you do want to pop up a MessageDialog act as a confirm dialog, then you need to complete all rest work that you previous do in javascript in your c# code.
For example, if you want to change some text of a html control, you need to prepare a complete html string, then check command status in CommandInvokedHandler callback and let webview navigate to(webView.NavigateToString) the new html string.
If you need to receive notifications and data in your app code sent from WebView-hosted script, you need to handle the ScriptNotify event. You can refer to this sample (The scenario6).
I currently have a listbox (part of a search criteria) that represents a list of strings that are retrieved one at a time via a pop-up window. However when the pop-up window closes the selected String is never added to the listbox. (I have confirmed that the hidden variable is updated and if you navigate away from the page after a search is performed and navigate back, the list box correctly shows Strings I had selected from the pop up previously). Any help would be greatly appreciated!
<script type="text/javascript">
function selectBook(bookId, extendedBookName) {
var idInput = jQuery("#myForm\\:bookNames");
if (idInput.val() == "") {
idInput.val(extendedBookName);
} else {
idInput.val(idInput.val() + '###' + extendedBookName);
}
}
</script>
...
<h:form id="myForm">
...
<ui:define name="form-fields">
<h:selectOneListbox id="booksListBox" size="3" style="width:470px">
<s:selectItems var="_var" value="#{bean.searchCriteria.bookNames}" label="#{_var}" noSelectionLabel="" />
</h:selectOneListbox>
<h:outputLink onclick="return openNewWindow('#{bean.booksLookupUrl}?#{bean.bookLookupParameters}', 'book');"
target="_blank">
<h:inputHidden id="bookNames" value="#{bean.searchCriteria.bookNames}" converter="StringListConverter"/>
<h:outputText value="Add"/>
</h:outputLink>
</ui:define>
...
</h:form>
This is javaScript that belongs to the lookup window. This calls the selectBook function
function selectBook(bookId, extendedBookName) {
var extendedName = unescape(extendedBookName);
window.opener.selectBook(bookId, extendedName);
window.close();
}
And for my Java code...
public class BookSearchCriteria implements Serializable {
...
private List<String> bookNames = new ArrayList<String>();
public List<String> getBookNames() {
return bookNames;
}
public void setBookNames(List<String> bookNames) {
this.bookNames = bookNames;
}
The StringListConverter code...
#FacesConverter("myStringListConverter")
public class StringListConverter implements Converter {
// this is used as a regex, so choose other separator carefully
private static final String MY_SEPARATOR = "###";
#Override
public Object getAsObject(FacesContext context, UIComponent component,
String value) {
if (value == null) {
return new ArrayList<String>();
}
return new ArrayList<String>(Arrays.asList(value.split(MY_SEPARATOR)));
}
#Override
public String getAsString(FacesContext context, UIComponent component,
Object value) {
if (value == null) {
return "";
}
return join((List<String>) value, MY_SEPARATOR);
}
/**
* Joins a String list, src: http://stackoverflow.com/q/1751844/149872
*
* #param list
* #param conjunction
* #return
*/
public static String join(List<String> list, String conjunction) {
StringBuilder sb = new StringBuilder();
boolean first = true;
for (String item : list) {
if (first) {
first = false;
} else {
sb.append(conjunction);
}
sb.append(item);
}
return sb.toString();
}
}
I don't really understand why you want to populate your listBox using a popup.
But if you modify the underlying bean values, you need to rerender the <h:selectOneListbox/> to reflect these changes. If you are using (or can use) the richfaces framework it can be done quite easily through an ajax call.
The ajax4jsf component called <a4j:jsFunction/> can do the job. For example in your parent page add :
<a4j:jsFunction name="refreshListbox" reRender="booksListBox" limitToList="true"/>
and in your popup just call this js function when a new book value is selected :
<script type="text/javascript">
window.opener.refreshListbox();
</script>
You could also use a <rich:modalPanel> instead of a popup to stay in the same page and interact more easily with your jsf components.
The page in the popup window is running some server-side Java code that creates new options for the dropdown menu. This has no absolutely no effect on the parent page until the parent page is reloaded and regenerated by the server. To avoid reloading the page, you need to create and select the new option using client-side JavaScript/jQuery code.
Assuming that the HTML code for the resulting option should look something like <option value="bookId">extendedBookName</option>, you can use this:
<script>
function addBook(bookId, extendedBookName) {
var newOption = jQuery('<option>').val(bookId).text(extendedBookName);
var idInput = jQuery('#myForm\\:bookNames');
idInput.append(newOption).val(bookId);
}
</script>
Demo: http://jsfiddle.net/5Cwjk/
Or, if the selection from the popup window is not guaranteed to be new, then you'll want to dynamically determine whether creating an option is necessary before doing so to avoid duplicates:
<script>
function addBook(bookId, extendedBookName) {
var idInput = jQuery('#myForm\\:bookNames');
if (idInput.val(bookId).val() != bookId) {
var newOption = jQuery('<option>').val(bookId).text(extendedBookName);
idInput.append(newOption).val(bookId);
}
}
</script>
Demo: http://jsfiddle.net/nTtY9/1/