In my asp.net application I used the async javascript callback.
The requirement is once the user enters the Postal code an async javascript callback function should be called. And the server side code must return me the city with respect to the postal code.
The coding I did is:
<asp:TextBox ID="txtPostCode" runat="server" CssClass="textbox" onchange="javascript: getCityAndStreet();" BorderStyle="Ridge" Height="20px" style="margin-left: 10px" Width="442px"></asp:TextBox>
This textbox onchange it will call the javascript function getCityAndStreet()
function getCityAndStreet()
{
var postalCode = document.getElementById('<%=txtPostCode.ClientID%>');
CallServer(postalCode.value, "");
}
function ReceiveCityAndStreet(rValue,context)
{
alert(rValue);
var city = document.getElementById('<%= txtCity.ClientID%>');
city.value = rValue;
}
Here the CallServer is the server side runtime javascript which is registered as below
protected void Page_Init(object sender, EventArgs e)
{
String cbReference = Page.ClientScript.GetCallbackEventReference(this, "arg", "ReceiveCityAndStreet", "context",true);
String callbackScript;
callbackScript = "function CallServer(arg, context)" + "{ " + "alert('Entered inside CallServer' + arg);" + cbReference + ";}";
Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "CallServer", callbackScript, true);
}
I implemented the ICallBackHandler and by this I got 2 methods:
string ICallbackEventHandler.GetCallbackResult()
{
return cityAndStreet;
}
void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
{
txtStreet.Enabled = true;
txtCity.Enabled = true;
cityAndStreet = eventArgument;
}
in page_load function I just disabled the txtStreet.Enabled. txtCity.Enabled text boxes and on the raise callbackevent I am enabling it.
The issue here is the RaiseCallBackEvent is not working. I mean its not been triggered implicitly.
(This application is not accessed directly in the browser it is accessed through the SharePoint site)
I think the problem is that your button actually does postback when you click on it. You do not need postback because you are calling server using AJAX. Try changing onchage handler to this:
onchange="getCityAndStreet();return false;"
This will cause your button not to trigger postback.
EDIT: Also i want to mention that you cannot change controls in RaiseCallBackEvent method. It is not an actual postback. You need to enable text fields using javascript in onSuccess method.
Related
I'm using the javascript from the answer in this question in a project of mine:
Adding Hyperlinks to ValidationSummary
It works really great. I've added it to the bottom of my masterpage (for some reason, even though it is inside $(document).ready, Page_Validators is null if i place it in the head section)
Anyway! I'm also adding some custom validators programatically on postback using this code:
public static CustomValidator ReturnErrorMessage(string message, string validationGroup, string controlToValidate = "")
{
CustomValidator control = new CustomValidator();
control.ID = "cv" + controlToValidate;
control.IsValid = false;
control.Text = " ";
control.ValidationGroup = validationGroup;
control.ErrorMessage = message;
control.ControlToValidate = controlToValidate;
return control;
}
However whenever I add a CustomValidator like that, in a button event, page_load or whatever, Page_Validators will be overridden and the errormessage will revert to the message without a anchor.
What gives? Am I doing something wrong or can someone explain what is happening?
I've tried debugging it and it does set the values correctly, but then it just reset afterwards.
I've tried for the heck of it and in $(document).ready set all validators as isvalid = false, and that gets overwritten too.
Im using asp.net 4.5 unobtrusive validation, but it does not make a difference if I turn it off.
Adding the javascript in code using Page.ClientScript.RegisterStartupScript at some point after the validator has been created does not work either.
If I don't add any validators in code everything works as expected.
I'm aware I can just add the anchor tags manually, but this is a lot of work to update existing validators instead of just tossing in a small script, so I'm hoping to get this to work.
You can use this code to test this:
using System;
using System.Web.UI.WebControls;
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
CustomValidator control = new CustomValidator();
control.ID = "cv" + txtName.ClientID;
control.IsValid = false;
control.Text = " ";
control.ValidationGroup = "errorGroup";
control.ErrorMessage = "Error message";
control.ControlToValidate = txtName.ClientID;
Form.Controls.Add(control);
}
}
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="jquery-3.3.1.min.js"></script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtName" runat="server"></asp:TextBox>
<asp:ValidationSummary ID="vsSummary" runat="server" ValidationGroup="errorGroup" ForeColor="Red" HeaderText="Error!" />
</div>
</form>
<script>
$(document).ready(function() {
var validators = Page_Validators; // returns collection of validators on page
$(validators).each(function() {
//get target control and current error validation message from each validator
//[0] is needed when using aspnet 4.5 unobtrusive validation
var validator = $(this)[0];
var errorMsg = validator.errormessage;
var targetControl = validator.controltovalidate;
//make link only if theres a control to target
if (targetControl) {
var errorMsgWithLink = "<a href='#" + targetControl + "' style='color: #FF3232;'> " + errorMsg + "</a>";
//update error message with anchor tag
validator.errormessage = errorMsgWithLink;
}
});
});
</script>
</body>
</html>
If you want you can try implementing your own 'CustomValidationSummary' control by following the same design pattern as mentioned at Reference Source by Microsoft, and modify the render method to include anchor tag to wrap error text, before it is passed into the writer method at line number 462.
I ended up using a extension method, adding the anchor tag in the method
public static void AddValidator(this Page p, string message, string validationGroup, string controlToValidate = "", bool addAnchorTags = true)
{
CustomValidator control = new CustomValidator();
control.ID = "cv" + controlToValidate;
control.IsValid = false;
control.Text = " ";
control.ValidationGroup = validationGroup;
control.ControlToValidate = controlToValidate;
if (addAnchorTags && !string.IsNullOrEmpty(controlToValidate))
{
control.ErrorMessage = "<a href='#" + controlToValidate + "' style='color: #FF3232;'> " + message + "</a>";
}
else
{
control.ErrorMessage = message;
}
p.Validators.Add(control);
}
I'm trying to open a ajaxToolkit:ModalPopupExtender with JavaScript but when I run my code and I call the function from the code behind this crash and show this error.
JavaScript runtime error: Unable to get property 'show' of undefined
or null reference
this is my JavaScript:
<script>
function closeChangeArea() {
$find('ModalChangeArea').hide();
}
function showChangeArea() {
$find('ModalChangeArea').show();
}
</script>
and this is my code:
protected void Btn_Click_Ch_Area(object sender, EventArgs e)
{
LinkButton lb = (LinkButton)sender;
GridViewRow gr = (GridViewRow)lb.NamingContainer;
Label ToolChange = (Label)gr.FindControl("Lbl_toolg");
Txt_Tool_Reasign.Text = ToolChange.Text;
ScriptManager.RegisterStartupScript(this, this.GetType(), "Pop", "showChangeArea();", true);
}
this is my ModalPoupExtender
<ajaxToolkit:ModalPopupExtender
ID="ModalChangeArea"
runat="server"
TargetControlID="hid"
PopupControlID="ChangeArea"
RepositionMode="RepositionOnWindowResizeAndScroll"
DropShadow="true"
PopupDragHandleControlID="moveArea">
</ajaxToolkit:ModalPopupExtender>
In asp.net control id is dynamically appended with container, in that case you will not get the control using $find to get control use clientid of asp.net control or set ClientIdMode = "Static".
Try below code to access element.
$find('<%= ModalChangeArea.ClientID %>').show();
$find('<%= ModalChangeArea.ClientID %>').hide();
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 have a small problem . If page is refreshed using F5 , TextBox should preserve its old value . In Page_Load() , if i keep // Loading(); then TextBox1 preserve its old value.
As soon as i remove comment , it loose value in TextBox1 .
Please tell me the reason behind it and What should be done to avoid it .
<script type="text/javascript">
function TextBox1_TextChanged() {
<%
Session["HitCount1"] = TextBox1.Text ;
%>
}
function getMyvalSession() {
var ff = "Loading Value";
return ff;
}
</script>
<body>
<form id="form1" runat="server">
<asp:TextBox ID="TextBox1" Name="TextBox1" runat="server"
AutoPostBack='true' onchange="TextBox1_TextChanged()"></asp:TextBox>
<%
string x = null;
x = Session["HitCount1"].ToString().Trim();
if ((x.Equals(null)) || (x.Equals("")))
{
// Session Variable is either empty or null .
}
else
{
TextBox1.Text = Session["HitCount1"].ToString();
}
%>
</form>
</body>
protected void Page_Load(object sender, EventArgs e)
{
// Loading();
}
void Loading()
{
String csname = "OnSubmitScript";
Type cstype = this.GetType();
// Get a ClientScriptManager reference from the Page class.
ClientScriptManager cs = Page.ClientScript;
// Check to see if the OnSubmit statement is already registered.
if (!cs.IsOnSubmitStatementRegistered(cstype, csname))
{
string cstext = " document.getElementById(\"TextBox1\").value = getMyvalSession() ; ";
cs.RegisterOnSubmitStatement(cstype, csname, cstext);
}
}
Combining inline server-side code and code-behind code is generally a bad idea. I would recommend just using the code-behind code.
This code:
function TextBox1_TextChanged() {
<%
Session["HitCount1"] = TextBox1.Text ;
%>
}
... is not going to have the effect of the (server-side) Session entry "HitCount1" getting set to Textbox1.Text, because TextBox1_TextChanged is a client-side function, and your assignment statement is going to happen on the server side. At run time, the chunk of server code will have been removed by the compiler, so TextBox1_TextChanged will be an empty function.
The rule of thumb: Things happen on the client, or they happen on the server on postback, or they happen on the server via Ajax calls. You can't mix client and server code together.
My recommendation: switch to doing everything in code-behind. When you have it working, if you have too many postbacks, investigate Ajax calls.
I am trying to get the value of the href as i need to pass a variable in query string
<a id="CA" class="CA" href='<%#"mysecondpage.aspx?ID=" + Td1.InnerText %>'
onclick="return popitup(this.href)" runat="server">comment</a>
I have to open a popup in which the "mysecondpage" should be open with a value inside a query string but this.href returns blank value and i dont know why it is not working as it worked inside itemtemplate (gridview) i have used table and filled data with angularJS repeat.
this is my popitup function:
function popitup(url) {
alert(url);
// window.open(url+id,'popup', 'width=700,height=800,scrollbars=no,resizable=no');
return false;
}
You are using a DataBinding expression <%# %>. So you have to call DataBind() in the Page_Load explicitly.
protected void Page_Load(object sender, EventArgs e)
{
DataBind();
}
If you are using Jquery,
Try this I hope it will help you
$(document).ready(function(){
$('#CA').on('click' function(event){
event.preventDefault();
var url = $(this).attr('href');
alert(url);
});
});
Get back to me if is not working