IPostBackEventHandler Interface
Defines the method ASP.NET server controls must implement to handle post back events.
For a list of all members of this type, see IPostBackEventHandler Members.
[Visual Basic] Public Interface IPostBackEventHandler [C#] public interface IPostBackEventHandler [C++] public __gc __interface IPostBackEventHandler [JScript] public interface IPostBackEventHandler
Classes that Implement IPostBackEventHandler
| Class | Description |
|---|---|
| Button | Displays a push button control on the Web page. |
| Calendar | Displays a single month calendar that allows the user to select dates and move to the next or previous month. |
| HtmlAnchor | Allows programmatic access to the HTML <a> tag on the server. |
| HtmlButton | Allows programmatic access to the HTML <button> tag on the server. |
| HtmlInputButton | Allows programmatic access to the HTML <input type= button>, <input type= submit>, and <input type= reset> elements on the server. |
| HtmlInputImage | Allows programmatic access to the HTML <input type= image> element on the server. |
| ImageButton | A control that displays an image and responds to mouse clicks on the image. |
| LinkButton | Displays a hyperlink style button control on a Web page. |
Remarks
To create a server control that captures form submit information from the browser, you must implement this interface. For more information on how to use this interface, see Capturing Postback Events.
Example
[Visual Basic, C#, C++] The following example defines a custom button server control that causes post back, captures the post back event using the RaisePostBackEvent method, and raises a Click event on the server.
[Visual Basic] Imports System Imports System.Web.UI Imports System.Collections Imports System.Collections.Specialized Namespace CustomControls <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> Public Class MyButton Inherits Control Implements IPostBackEventHandler ' Define the Click event. Public Event Click As EventHandler ' Invoke delegates registered with the Click event. Protected Overridable Sub OnClick(e As EventArgs) RaiseEvent Click(Me, e) End Sub ' Define the method of IPostBackEventHandler that raises change events. Public Sub RaisePostBackEvent(eventArgument As String) _ Implements IPostBackEventHandler.RaisePostBackEvent OnClick(New EventArgs()) End Sub Protected Overrides Sub Render(output As HtmlTextWriter) output.Write("<INPUT TYPE = submit name = " & Me.UniqueID & _ " Value = 'Click Me' />") End Sub End Class End Namespace [C#] using System; using System.Web.UI; using System.Collections; using System.Collections.Specialized; namespace CustomControls { [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] public class MyButton: Control, IPostBackEventHandler { // Defines the Click event. public event EventHandler Click; //Invoke delegates registered with the Click event. protected virtual void OnClick(EventArgs e) { if (Click != null) { Click(this, e); } } // Define the method of IPostBackEventHandler that raises change events. public void RaisePostBackEvent(string eventArgument){ OnClick(new EventArgs()); } protected override void Render(HtmlTextWriter output) { output.Write("<INPUT TYPE = submit name = " + this.UniqueID + " Value = 'Click Me' />"); } } } [C++] #using <mscorlib.dll> #using <System.Web.dll> #using <System.dll> using namespace System; using namespace System::Web::UI; using namespace System::Collections; using namespace System::Collections::Specialized; [System::Security::Permissions::PermissionSet(System::Security::Permissions::SecurityAction::Demand, Name=S"FullTrust")] public __gc class MyButton: public Control, public IPostBackEventHandler { // Defines the Click event. public: __event EventHandler* Click; //Invoke delegates registered with the Click event. protected: virtual void OnClick(EventArgs* e) { if (Click != 0) { Click(this, e); } } // Define the method of IPostBackEventHandler that raises change events. public: void RaisePostBackEvent(String* eventArgument){ OnClick(new EventArgs()); } protected: void Render(HtmlTextWriter* output) { output->Write(S"<INPUT TYPE = submit name = {0} Value = 'Click Me' />", this->UniqueID); } };
[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Namespace: System.Web.UI
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
Assembly: System.Web (in System.Web.dll)
See Also
IPostBackEventHandler Members | System.Web.UI Namespace | Capturing Postback Events