Control.RenderChildren Method
Outputs the content of a server control's children to a provided HtmlTextWriter object, which writes the content to be rendered on the client.
[Visual Basic] Protected Overridable Sub RenderChildren( _ ByVal writer As HtmlTextWriter _ ) [C#] protected virtual void RenderChildren( HtmlTextWriter writer ); [C++] protected: virtual void RenderChildren( HtmlTextWriter* writer ); [JScript] protected function RenderChildren( writer : HtmlTextWriter );
Parameters
- writer
- The HtmlTextWriter object that receives the rendered content.
Remarks
This method notifies ASP.NET to render any Active Server Pages (ASP) code on the page. If no ASP code exists on the page, this method renders any child controls for the server control.
Example
[Visual Basic, C#, C++] The following example overrides the RenderChildren method in a custom server control. It determines whether the current control has any child controls in its ControlCollection object. If it does, it uses the Count property to iterate through the collection. As it encounters each child control, it uses the RenderControl method to render the parent control, and all of its child controls, to the containing page.
[Visual Basic, C#, C++] The overridden Render method then calls the overridden RenderChildren method.
[Visual Basic] ' Override default implementation to Render children according to needs. Protected Overrides Sub RenderChildren(output As HtmlTextWriter) If HasControls() Then ' Render Children in reverse order. Dim i As Integer For i = Controls.Count - 1 To 0 Step -1 Controls(i).RenderControl(output) Next End If End Sub 'RenderChildren Protected Overrides Sub Render(output As HtmlTextWriter) output.Write(("<br>Message from Control : " + Message)) output.Write(("Showing Custom controls created in reverse" + "order")) ' Render Controls. RenderChildren(output) End Sub End Class [C#] // Override default implementation to Render children according to needs. protected override void RenderChildren(HtmlTextWriter output) { if (HasControls()) { // Render Children in reverse order. for(int i = Controls.Count - 1; i >= 0; --i) { Controls[i].RenderControl(output); } } } protected override void Render(HtmlTextWriter output) { output.Write("<br>Message from Control : " + Message); output.Write("Showing Custom controls created in reverse" + "order"); // Render Controls. RenderChildren(output); } } [C++] // Override default implementation to Render children according to needs. protected: void RenderChildren(HtmlTextWriter* output) { if (HasControls()) { // Render Children in reverse order. for(int i = Controls->Count - 1; i >= 0; --i) { Controls->Item[i]->RenderControl(output); } } } void Render(HtmlTextWriter* output) { output->Write(S"<br>Message from Control : {0}", Message); output->Write(S"Showing Custom controls created in reverse order"); // Render Controls. RenderChildren(output); } };
[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
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
See Also
Control Class | Control Members | System.Web.UI Namespace | Render | RenderControl