I have an HTML page loaded in the webbrowser control. The HTML has a javascript function windows.print which tries to print from my browser. Please how can I pass the windows.print() function to print through Winforms C#. Or how can I pass the javascript object I want printed into the C# to be printed.
Please I am a beginner with C#, I would appreciate a detailed explanation. Thanks so much!
you can probably do something like this
namespace WindowsFormsApplication
{
// This first namespace is required for the ComVisible attribute used on the ScriptManager class.
using System.Runtime.InteropServices;
using System.Windows.Forms;
// This is your form.
public partial class Form1 : Form
{
// This nested class must be ComVisible for the JavaScript to be able to call it.
[ComVisible(true)]
public class ScriptManager
{
// Variable to store the form of type Form1.
private Form1 mForm;
// Constructor.
public ScriptManager(Form1 form)
{
// Save the form so it can be referenced later.
mForm = form;
}
// This method can be called from JavaScript.
public void MethodToCallFromScript()
{
// Call a method on the form.
mForm.DoSomething();
}
// This method can also be called from JavaScript.
public void AnotherMethod(string message)
{
MessageBox.Show(message);
}
}
// This method will be called by the other method (MethodToCallFromScript) that gets called by JavaScript.
public void DoSomething()
{
// Indicate success.
MessageBox.Show("It worked!");
}
// Constructor.
public Form1()
{
// Boilerplate code.
InitializeComponent();
// Set the WebBrowser to use an instance of the ScriptManager to handle method calls to C#.
webBrowser1.ObjectForScripting = new ScriptManager(this);
// Create the webpage.
webBrowser1.DocumentText = #"<html>
<head>
<title>Test</title>
</head>
<body>
<input type=""button"" value=""Go!"" onclick=""window.external.MethodToCallFromScript();"" />
<br />
<input type=""button"" value=""Go Again!"" onclick=""window.external.AnotherMethod('Hello');"" />
</body>
</html>";
}
}
}
Related
I have a JavaFX application that makes heavy use of a WebView. I am trying to insert an object into the DOM that the JavaScript code can use, and I need these objects to be available as new pages are loaded.
However, when I run the program, FirebugLite shows the object in the DOM, but the functions do not execute.
According to some Oracle documentation, this seems to be the appropriate way to provide upcalls from JavaScript to Java. I've also seen a few StackOverflow posts explaining the same thing.
What am I missing? I'm using Java 8, Update 51, 64-bit on Windows 7.
Java:
public class DemoApplication extends Application {
Debug debug;
#Override
public void start(final Stage stage) throws Exception {
debug = new Debug();
WebView browser = new WebView();
WebEngine webEngine = browser.getEngine();
webEngine.getLoadWorker().stateProperty().addListener(
new ChangeListener<Worker.State>() {
#Override
public void changed(ObservableValue<? extends Worker.State> observable, Worker.State oldValue, Worker.State newValue) {
if (newValue == Worker.State.SUCCEEDED) {
JSObject windowObject = (JSObject) webEngine.executeScript("window");
windowObject.setMember("Debug", debug);
}
}
}
);
webEngine.load("http://localhost:8080/page1.html");
stage.setScene(new Scene(browser));
stage.show();
}
}
public class Debug {
public void print(final Object text) {
System.err.println(text);
}
}
HTML/JavaScript:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<script type="text/javascript" src="https://getfirebug.com/firebug-lite.js"></script>
<script>
Debug.print("Hello");
</script>
</head>
<body>
Page 1
Page 2
</body>
</html>
Firebug Screenshot:
I believe what is happening is that WebEngine loads the page, the ChangeListener is invoked at various points (SCHEDULED, RUNNING, SUCCEEDED, etc.). Once the Worker.State.SUCCEEDED event happens, the page has already finished loading all content and has finished executing that content as well. So basically my calls to Debug.print() in the JavaScript code were happening early and calling on an object that was undefined or null.
That's my best guess anyway, because if I add a JavaScript function that is executed by the Java portion after adding in the objects, everything works as expected.
This is how I modified the JavaScript side:
<script>
// callback that uses java objects
window.ready = function() {
Debug.print("Hello");
}
</script>
And this is how I modified the Java side:
webEngine.getLoadWorker().stateProperty().addListener(
new ChangeListener<Worker.State>() {
#Override
public void changed(ObservableValue<? extends Worker.State> observable, Worker.State oldValue, Worker.State newValue) {
if (newValue == Worker.State.SUCCEEDED) {
JSObject windowObject = (JSObject) webEngine.executeScript("window");
windowObject.setMember("Debug", debug); // insert object
windowObject.call("ready"); // execute callback
}
}
}
);
The key changes here are the ready() function in the JavaScript, and invoking that function after injecting the objects on the Java side. This ensures those objects are available before being called.
I tried this on a few different pages and when going from page to page, when the ready() function was called Debug.print() executed properly, even when using WebEngine.reload(), or WebHistory.go().
Utilizing several code snippets I've attempted to hook up an ActiveX object with a Javascript event handler. I'm unable to identify why the event handler isn't being called.
Github Repository with project.
Update
By placing the javascript call to SayHello() in an 'onLoad' event, I was able to get the ActiveX event to fire. Now I'm looking toward the C# call, and how to hook it into the ActiveX object utilized by Javascript.
(This may also have relied on enable local scripts from the Advanced options of IE).
Message Continued
The event handler is done in the same form as described for this question.
<script for="MyObject" event="OnUpdateString(stuff)">
document.write("<p>" + stuff);
document.writeln("</p>");
</script>
Utilizing MSDN documentation I created a WinForms app that contains a WebBrowser control that acts as the ObjectForScripting (not related to the issue). This container makes a call out to the ActiveX event, but is unhandled by the Javascript. I'm including the C# Form code to be complete in the ActiveX interactions and to allow this to be a reference for future users of ActiveX and/or WebBrowser control.
This file is intended to be used with a new Windows Form project where a WebBrowser control was added to the main window.
C# Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Security.Permissions;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using ActiveXObjectSpace;
namespace TestActiveX
{
[PermissionSet(SecurityAction.Demand, Name = "FullTrust")]
[System.Runtime.InteropServices.ComVisibleAttribute(true)]
public partial class Form1 : Form
{
MyObject myObject = new MyObject();
public Form1()
{
InitializeComponent();
Text = "ActiveX Test";
Load += new EventHandler(Form1_Load);
}
private void Form1_Load(object sender, EventArgs e)
{
webBrowser1.AllowWebBrowserDrop = false;
webBrowser1.ObjectForScripting = this;
webBrowser1.Url = new Uri(#"C:\path\to\TestPage.html");
// Call ActiveX
myObject.SayHello("C# Launch");
}
public string ControlObject()
{
return "<p>Control Object Called.</p>";
}
}
}
Combining from the help of two other code snippets I created a the ActiveX object. Which, as noted, needs to be registered after being built.
C# ObjectX.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
/// http://blogs.msdn.com/b/asiatech/archive/2011/12/05/how-to-develop-and-deploy-activex-control-in-c.aspx
/// https://stackoverflow.com/questions/11175145/create-com-activexobject-in-c-use-from-jscript-with-simple-event
///
/// Register with %NET64%\regasm /codebase <full path of dll file>
/// Unregister with %NET64%\regasm /u <full path of dll file>
namespace ActiveXObjectSpace
{
/// <summary>
/// Provides the ActiveX event listeners for Javascript.
/// </summary>
[Guid("4E250775-61A1-40B1-A57B-C7BBAA25F194"), InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
public interface IActiveXEvents
{
[DispId(1)]
void OnUpdateString(string data);
}
/// <summary>
/// Provides properties accessible from Javascript.
/// </summary>
[Guid("AAD0731A-E84A-48D7-B5F8-56FF1B7A61D3"), InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
public interface IActiveX
{
[DispId(10)]
string CustomProperty { get; set; }
}
[ProgId("MyObject")]
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.AutoDual)]
[Guid("7A5D58C7-1C27-4DFF-8C8F-F5876FF94C64")]
[ComSourceInterfaces(typeof(IActiveXEvents))]
public class MyObject : IActiveX
{
public delegate void OnContextChangeHandler(string data);
new public event OnContextChangeHandler OnUpdateString;
// Dummy Method to use when firing the event
private void MyActiveX_nMouseClick(string index)
{
}
public MyObject()
{
// Bind event
this.OnUpdateString = new OnContextChangeHandler(this.MyActiveX_nMouseClick);
}
[ComVisible(true)]
public string CustomProperty { get; set; }
[ComVisible(true)]
public void SayHello(string who)
{
OnUpdateString("Calling Callback: " + who);
}
}
}
Last is the html page which is to be loaded by the browser or container. It loads the ActiveX object successfully and contains an event handler for OnUpdateString. It checks that the ActiveX provided function, SayHello, can be called and makes the call.
I'd expect the Javascript and C# call to be written to the document, but no such entries are written.
TestPage.html
<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>DemoCSharpActiveX webpage</title>
</head>
<body>
<script type="text/javascript">
window.objectLoadFailure = false;
</script>
<object id="MyObject" onerror="window.objectLoadFailure = true" classid="clsid:7A5D58C7-1C27-4DFF-8C8F-F5876FF94C64"></object>
<script for="MyObject" event="OnUpdateString(stuff)">
document.write("<p>" + stuff);
document.writeln("</p>");
</script>
<script type="text/javascript">
document.write("<p>Loaded ActiveX Object: " + !window.objectLoadFailure);
document.writeln("</p>");
if (typeof window.external.ControlObject !== "undefined") {
document.write(window.external.ControlObject());
}
var obj = document.MyObject;
if (typeof obj.SayHello !== "undefined") {
document.writeln("<p>Can Call say hello</p>")
}
obj.SayHello("Javascript Load");
</script>
</body>
</html>
The containing page shows this output
Output
Loaded ActiveX Object: true
Control Object Called.
Can Call say hello
Updated, as long as you can get the <object> instantiated from HTML (MyObject.object != null), the ultimate problem with your JavaScript event handler is simply that you kill the original HTML document with document.write before you call MyObject.SayHello("Javascript Load"), and replace it with <p>Loaded ActiveX Object: ...</p>. By then, all original JavaScript event handlers are gone.
Thus, the following works fine, the event gets fired and handled (with an alert):
<!DOCTYPE html>
<html>
<head>
<title>DemoCSharpActiveX webpage</title>
</head>
<body>
<script type="text/javascript">
window.objectLoadFailure = false;
</script>
<object id="MyObject" onerror="window.objectLoadFailure = true" classid="clsid:7A5D58C7-1C27-4DFF-8C8F-F5876FF94C64"></object>
<script type="text/javascript" for="MyObject" event="OnUpdateString">
alert("Hello from event handler");
</script>
<script type="text/javascript" for="window" event="onload">
alert("Hello from window.onload!");
alert(MyObject.object);
MyObject.SayHello("Javascript Load");
</script>
</body>
</html>
To make your original logic work, you can manipulate the DOM directly instead of using document.write. Or, at least call it after OnUpdateString has been fired and handled.
Now that I've seen the full source, I can tell quite a few things going wrong here.
You can hit a break point inside SayHello because you create MyObject from C# [MyObject myObject = new MyObject()] and call it from C# [myObject.SayHello("C# Launch")]. Remove that and you'll see it never gets invoked when you call it from JavaScript [obj.SayHello("Javascript Load")].
That leads to another issue: the <object> doesn't get create successfully, and even more so, none of your JavaScript scripts even run, because your test HTML file is served from the local file system (via file:// protocol). This is a security restriction. Try changing your script like below to see none of the alerts actually show up:
<script type="text/javascript" for="window" event="onload">
alert("Hello from window.onload!");
alert(MyObject.object) // null! object wasn't created...
document.write("<p>Loaded ActiveX Object: " + !window.objectLoadFailure);
document.writeln("</p>");
if (typeof window.external.ControlObject !== "undefined") {
document.write(window.external.ControlObject());
}
var obj = document.MyObject;
if (typeof obj.SayHello !== "undefined") {
document.writeln("<p>Can Call say hello</p>")
}
obj.SayHello("Javascript Load");
</script>
There're several ways of fixing it. The easiest one is probably to use "Mark of Web". The hardest one would be to provide a custom implementation of IInternetSecurityManager. I myself would use yet another method - Internet Feature Control - and disable FEATURE_LOCALMACHINE_LOCKDOWN, FEATURE_BLOCK_LMZ_SCRIPT, FEATURE_BLOCK_LMZ_OBJECT keys. You can use following code I adapted from my other related answer:
// static constructor, runs first
static Form1()
{
SetWebBrowserFeatures();
}
static void SetWebBrowserFeatures()
{
// don't change the registry if running in-proc inside Visual Studio
if (LicenseManager.UsageMode != LicenseUsageMode.Runtime)
return;
var appName = System.IO.Path.GetFileName(System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName);
var featureControlRegKey = #"HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\FeatureControl\";
Registry.SetValue(featureControlRegKey + "FEATURE_BROWSER_EMULATION",
appName, GetBrowserEmulationMode(), RegistryValueKind.DWord);
// enable the features which are "On" for the full Internet Explorer browser
Registry.SetValue(featureControlRegKey + "FEATURE_ENABLE_CLIPCHILDREN_OPTIMIZATION",
appName, 1, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_AJAX_CONNECTIONEVENTS",
appName, 1, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_GPU_RENDERING",
appName, 1, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_WEBOC_DOCUMENT_ZOOM",
appName, 1, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_NINPUT_LEGACYMODE",
appName, 0, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_LOCALMACHINE_LOCKDOWN",
appName, 0, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_BLOCK_LMZ_SCRIPT",
appName, 0, RegistryValueKind.DWord);
Registry.SetValue(featureControlRegKey + "FEATURE_BLOCK_LMZ_OBJECT",
appName, 0, RegistryValueKind.DWord);
}
static UInt32 GetBrowserEmulationMode()
{
int browserVersion = 0;
using (var ieKey = Registry.LocalMachine.OpenSubKey(#"SOFTWARE\Microsoft\Internet Explorer",
RegistryKeyPermissionCheck.ReadSubTree,
System.Security.AccessControl.RegistryRights.QueryValues))
{
var version = ieKey.GetValue("svcVersion");
if (null == version)
{
version = ieKey.GetValue("Version");
if (null == version)
throw new ApplicationException("Microsoft Internet Explorer is required!");
}
int.TryParse(version.ToString().Split('.')[0], out browserVersion);
}
if (browserVersion < 7)
{
throw new ApplicationException("Unsupported version of Microsoft Internet Explorer!");
}
UInt32 mode = 11000; // Internet Explorer 11. Webpages containing standards-based !DOCTYPE directives are displayed in IE11 Standards mode.
switch (browserVersion)
{
case 7:
mode = 7000; // Webpages containing standards-based !DOCTYPE directives are displayed in IE7 Standards mode.
break;
case 8:
mode = 8000; // Webpages containing standards-based !DOCTYPE directives are displayed in IE8 mode.
break;
case 9:
mode = 9000; // Internet Explorer 9. Webpages containing standards-based !DOCTYPE directives are displayed in IE9 mode.
break;
case 10:
mode = 10000; // Internet Explorer 10.
break;
}
return mode;
}
Now, your scripts do run, but the <object> still doesn't get created (alert(MyObject.object) shows null). Finally, you'd need to implement IObjectSafety interface on your ActiveX object and site-lock it to only your very own HTML pages. Without proper IObjectSafety the object won't be getting created under default IE security settings. Without site-locking it might become a huge security threat, as any malicious script possibly could create and use your object outside the context of your application.
Updated to address the comment:
I've updated the project with your provided example, note that I had
made a change such that there is a C# button and a Javascript button
to fire the event. The JS button works, but C# does not fire. I'm
looking for a "Hello from: C# button" alert.
In your code, the myObject instance gets created and accessed exclusively from C#:
MyObject myObject = new MyObject();
// ...
private void button1_Click(object sender, EventArgs e)
{
// Call ActiveX
myObject.SayHello("C# Button");
}
This instance has nothing to do with the <object id="MyObject" onerror="window.objectLoadFailure = true" classid="clsid:7A5D58C7-1C27-4DFF-8C8F-F5876FF94C64"></object> instance that you create from HTML. They're two separate, unrelated objects. Your event handlers only work for the latter <object> instance. You don't even subscribe to any events on the new MyObject() instance.
If I understand your goal correctly, you need this:
private void button1_Click(object sender, EventArgs e)
{
// Call ActiveX
//myObject.SayHello("C# Button");
this.webBrowser1.Document.InvokeScript("eval",
new[] { "MyObject.SayHello('C# Button')" });
}
Now, the JavaScript event handler would get invoked and you'd see the "C# Button" alert.
I am calling an static web method, the method is written in an aspx.cs file having two public classes:
public class Employee
{
public string EmployeeNumber;
public string FullName;
public string LoginName;
public string EmailID;
public string Phone;
}
public partial class CustomWebMethods : LayoutsPageBase
{
[WebMethod]
public static List<Employee> GetEmployeeDetails(string employeeLoginName)
{
List<Employee> lstEmployeeDetail = new List<Employee>();
//do something
return lstEmployeeDetail;
}
}
If I keep the public class employee in the same page then ajax call is working fine.
But if I move the employee to another class library project and add reference of that project, ajax call is not working. Why?
Javascript method not able to call the web method at all.
This is because of WebMethod attribute internal works. When you mark some method with this attribute, it will be available through PageName.aspx/MethodName url.
Then, after moving this method to outer library, you moving it from the page methods too, and after that it's not available.
So, if you want to refactor your code, you have to add the WebService to your project, from that class you can call methods from other library.
You can also create a javascript proxy on your client like this:
<asp:ServiceReference InlineScript="true" Path="~/CustomersService.asmx"/>
Or use the ScriptManager for it, like this:
<asp:ScriptManager ID="sm" runat="server" EnablePageMethods="true" />
After that you can use this proxy instead of ajax call.
<script type="text/javascript">
function Add()
{
var x = $get("txtX").value;
var y = $get("txtY").value;
PageMethods.Add(x, y, OnWSAdd);
}
function OnWSAdd(result)
{
$get("spanAddResult").innerHTML += result;
}
</script>
Old, but great article about Understanding ASP.NET AJAX Web Services.
How do I conditionally invoke JavaScript from a bean in JSF 2?
I have a class that uses PrimeFaces which uploads user files to a particular folder, but if the user attempts to upload a file with the same name as one that is already present, I want JavaScript in this case to open up a box on the screen asking the user if he wants to overwrite the old file, or cancel the operation. If no file with that name is present, then JavaScript is not called.
I know how to test that a folder has a particular file in it, it is just that I need to know how to invoke JavaScript conditionally.
I would most appreciate any advice on this.
I have looked at variopus resources online, but still cannot get the application to work correctly. basically, this is what I have done, in an included xhtml page I have the following code for the file upload:
<p:fileUpload id="fileUpload" fileUploadListener="#{filters.upload}"
allowTypes="#{filters.uploadTypes}" invalidFileMessage="#{filters.uploadBadType}"
sizeLimit="#{filters.uploadSize}" invalidSizeMessag="#{filters.uploadBadSize}"
update="fileUpload fileTable uploadMessage" description="Select Text File"
disabled="#{filters.disableFileUploadButton}"/>
<!--- Then further in the same file is this: -->
<p:remoteCommand name="remoteCommandOverwrite" actionListender="#{filters.execOverwrite}"/>
The parent xhtml page that includes the above I have the foolowing JavaScript:
<script type="text/javascript">
function popupConfirm() {
var overwrite = confirm('Warning: This will overwrite the existing file - Do you confirm this?');
if (overwrite) remoteCommandOverwrite([{name: overwrite, value: true}]);
}
</script>
In my bean I have the following code in three methods:
public void upload(FileUploadEvent event) {
FacesMessage msg = new FacesMessage("Success! ", event.getFile().getFileName() + " is uploaded.");
FacesContext.getCurrentInstance().addMessage(null, msg);
overwrite = false;
// Do what you want with the file
try {
copyFile(event.getFile().getFileName(), event.getFile().getInputstream());
} catch (IOException e) {
e.printStackTrace();
}
}
public void copyFile(String fileName, InputStream in) {
// Initialization etc.
File file = new File(uploadFull + fileName);
if (file.exists()) {
RequestContext.getCurrentInstance().execute("popupConfirm()");
// Then test to see if overwrite is true or false, and act accordingly
}
// Then I am supposed to get the value of overwrite here:
public void execOverwrite() {
System.out.println("### execOverwrite() ###");
FacesContext context = FacesContext.getCurrentInstance();
Map<String, String> map = context.getExternalContext().getRequestParameterMap();
String soverwrite = (String) map.get("overwrite");
if (soverwrite.equals("true")) {
overwrite = true;
System.out.println("overwrite: true");
}
}
What I am trying to do is first to invoke conditionally the JavaScript function popupConfirm(). On clicking the "Upload" button that is invoked if the codition is true, which is what I want. This is then supposed to call
That works and brings up the confirm() box, but the is never called, so the method execOverwrite() in my bean is also never called, and I cannot pick up the return value and pass it to the code inside the method copyFile(). What is going wrong?
I put this problem on the back burner for about a week, and have just got back to it. I got it to work, and can pass a value back to the bean, but somehow I need to resume execution from the place where JavaScript is called.
To sumarize, my JavaScript contains the following code:
<script type="text/javascript">
function popupConfirm() {
var overwrite = confirm('Warning: This will overwrite the existing file - Do you confirm this?');
if (overwrite) remoteCommandOverwrite([{name: 'overwrite', value: 'true'}]);
}
</script>
And in the xhtml code I have:
<p:fileUpload id="fileUpload" fileUploadListener="#{filters.upload}" ...../>
<!-- Other code -->
<p:remoteCommand name="remoteCommandOverwrite" actionListener="#{filters.execOverwrite}"/>
Then on clicking the file upload button after clicking the choose file button, the code in the JavaScript, as listed above, is executed:
RequestContext.getCurrentInstance().execute("popupConfirm()");
Then on clicking "OK" in the dialog box, this method in the same bean is called:
public void execOverwrite() {
FacesContext context = FacesContext.getCurrentInstance();
Map<String, String> map = context.getExternalContext().getRequestParameterMap();
String soverwrite = map.get("overwrite");
if (soverwrite.equals("true")) {
overwrite = true; }
}
}
where the flag "overwrite" will eventually be tested to see if it is true.
Using various print statements I check that this works. However, the code does not resume executing after encountering the statement: RequestContext.getCurrentInstance().execute("popupConfirm()"); regardless of whether I enter "OK" or "Cancel" in the dialog, which is what i want it to do. It looks as if a callback of some type is required, and would most appreciate some ideas.
According to your tag, you are using PrimeFaces, so there is an easy way to invoke a javascript function from a server side event managed bean method when the browser has completed processing the server response. PrimeFaces gives you a utility class called RequestContext.
public void doActionListenerMethod() {
if (!isValid()) {
RequestContext.getCurrentInstance().execute("MyJSObject.doClientSideStuff()");
}
}
The following will execute the string argument as a Javascript when JSF has finished rendering on the client.
I have read WebBrowser Control from .Net — How to Inject Javascript, Is it possible to call Javascript method from C# winforms and many others. Those examples were returns function value or alert window (synchronous calls). I have to get result from event handler (async call):
<script type="text/javascript">
window.onload = function() {
var o = new M.Build(document.getElementById("ZID"));
M.Events.observe(o, o.Events.Success, function() {
// I have to get some value!!
});
M.Events.observe(o, o.Events.Fault, function() {
// I have to get some value!!
});
}
</script>
Calling C# from JavaScript
Simply put, you can expose a C# object
to the WebBrowser that the JavaScript
can call directly The WebBrowser
class exposes a property called
ObjectForScripting that can be set by
your application and becomes the
window.external object within
JavaScript. The object must have the
ComVisibleAttribute set true
C#:
[System.Runtime.InteropServices.ComVisibleAttribute(true)]
public class ScriptInterface
{
public void callMe()
{
… // Do something interesting
}
}
webBrowser1.ObjectForScripting = new ScriptInterface();
Javascript:
window.external.callMe();
Calling JavaScript in a WebBrowser control from C#
This is code I have. In the DocumentCompleted event ('cause I'm getting a page from online)
var wb = (WebBrowser)sender
//Lots of other stuff
object obj = wb.Document.InvokeScript("MyFunctionName");
Create a function that returns whatever value you need and invoke away.
You can also inject a script into the page
string js = "function MyFunctionName(){alert('Yea!');}";
HtmlElement el = wb.Document.CreateElement("script");
IHTMLScriptElement element2 = (IHTMLScriptElement)el.DomElement;
element2.text = js;
head.AppendChild(el);
which can then be invoked. That's what I've done.
If your webBrowser control is in a form, you can do the following:
[System.Runtime.InteropServices.ComVisibleAttribute(true)]
public class Form1
{
public Form1()
{
InitializeComponent();
webBrowser1.ObjectForScripting = this;
}
public void CallMe()
{
//.... this method can be called in javascript via window.external.CallMe();
}
}