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RadConfirm Dialog

The RadConfirm dialog presents a message and displays "OK" and "Cancel" buttons for the user. As with the other RadWindow dialogs, the message is not limited to text: you can supply a string of HTML for richer formatting.

Unlike its regular browser counterpart, this version of the confirm dialog is non-blocking, so the rest of the page continues processing even before the dialog closes. Because the dialog is non-blocking it's designed to respond via a callback.

In order to use this dialog you need to have a RadWindowManager on the page.

At a minimum, the RadConfirm function takes two arguments, and HTML string with the message, and the name of a callback function that deals with the results. The callback takes a single parameter, whose value is True or False, depending on whether the user clicks "OK" or "Cancel". Additionally you can provide parameters to set the width, height, title and image URL.

The RadConfirm returns the client result as an argument in its Callback function only, as opposed to the standard browser confirm() function - the radconfirm() function returns a reference to the RadWindow dialog that is created and not the result.

To see when and how you can replace the standard confirm method with radconfirm, examine the Confirm Dialog Integration live demo.

Calling RadConfirm via JavaScript

The minimum required to show the RadConfirm is a message and the callback function:

<telerik:RadWindowManager ID="RadWindowManager1" runat="server">
<script type="text/javascript">
    function confirmCallBackFn(arg)
        radalert("Confirm returned the following result: " + arg);
<button onclick="radconfirm('Are you sure?', confirmCallBackFn); return false;">Show radconfirm</button>

The full syntax of the radconfirm() function is as follows:

var oConfirm = radconfirm(text, callBackFn, oWidth, oHeight, callerObj, oTitle, imgUrl);

Here is an example with all the parameters set:

<telerik:RadWindowManager ID="RadWindowManager1" runat="server">
<script type="text/javascript">
    function showRadConfirm() {
        var width, height = "150px";
        var title = "Confirm title"
        var text = "Are you sure?";
        var imgUrl = "";
        radconfirm(text, callBackFn, width, height, null, title, imgUrl);
    function callBackFn(arg) {
        radalert("Confirm returned the following result: " + arg);
<button onclick="showRadConfirm(); return false;">Show radconfirm</button>

where you can set optional width, height, title and image URL for the RadConfirm dialog.

This method also returns a reference to the RadAlert object (which is essentially a RadWindow), so you can use the RadWindow's client-side API on it to further change it (titlebar icon, behaviors, etc.)

Calling RadConfirm from the code-behind

Since Q1 2011 the RadWindowManager offers a built-in server-side method to call the RadConfirm:

    protected void Page_Load(object sender, EventArgs e)
        RadWindowManager RadWindowManager1 = new RadWindowManager();
        RadWindowManager1.RadConfirm("Are you sure?", "confirmCallBackFn", 300, 200, null, "My Confirm", "myConfirmImage.png");

        string script = "function confirmCallBackFn(arg){ radalert(\"Confirm returned the following result: \" + arg); };";
        ScriptManager.RegisterStartupScript(Page, Page.GetType(), "key", script, true);

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    Dim RadWindowManager1 As RadWindowManager = New RadWindowManager()
    RadWindowManager1.RadConfirm("Are you sure?", "confirmCallBackFn", 300, 200, Nothing, "My Confirm", "myConfirmImage.png")
    Dim script As String = "function confirmCallBackFn(arg){ radalert(""Confirm returned the following result: "" + arg); };"
    ScriptManager.RegisterStartupScript(Page, Page.[GetType](), "key", script, True)
End Sub   

Strings passed into this method must be properly formatted and escaped for HTML and JavaScript. Please see the related article Calling the Predefined Dialogs from the Server Methods.

The callback function is a client-side JavaScript function which is executed when the dialog is closed.

The Caller object parameter should have a null (Nothing) value, as it exists only for backwards compatibility.

If you change the default image the new one you provide should be 32px by 32px for best results. The string you pass to change the image URL can be:

  • an absolute URL, or a relative URL that can be resolved on the client (i.e. "~/" is not allowed). This will set the image the URL points to
  • an empty string - this will remove the default image and leave the space empty
  • null - the behavior is the same as if no argument is provided - i.e. the default image is kept

The appearance of the confirm dialog is controlled by two things: the Skin property of the RadWindowManager, and the values you pass in as arguments to RadConfirm. The arguments can include the HTML string you pass in as a message, the width, the height, and the Title string. The Skin property controls not only the appearance of the popup's title bar, but also the layout of the dialog: its icon, button style, and so on. This dialog layout and appearance is controlled by the confirm dialog template associated with the Skin. For details on how to customize the template, see Templates.

See Also

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