Control Class
Defines the properties, methods, and events that are shared by all ASP.NET server controls.
For a list of all members of this type, see Control Members.
System.Object
System.Web.UI.Control
Derived classes
[Visual Basic] Public Class Control Implements IComponent, IDisposable, IParserAccessor, _ IDataBindingsAccessor [C#] public class Control : IComponent, IDisposable, IParserAccessor, IDataBindingsAccessor [C++] public __gc class Control : public IComponent, IDisposable, IParserAccessor, IDataBindingsAccessor [JScript] public class Control implements IComponent, IDisposable, IParserAccessor, IDataBindingsAccessor
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Remarks
This is the primary class that you derive from when you develop custom ASP.NET server controls. Control does not have any user interface (UI) specific features. If you are authoring a control that does not have a UI, or combines other controls that render their own UI, derive from Control.
ASP.NET server controls include ASP.NET pages. Pages are instantiations classes derived from the Page class when a request for an ASP.NET page is processed. Also included are literal controls (strings of HTML and text that are not processed on the server), HTML server controls, Web server controls, and any custom server controls that you create or download.
Example
The following example demonstrates a custom server control that derives from the Control class. The InnerContent class overrides the Control.Render method, checks to see if the class has any child controls on the page and determines whether the first child of the control is a literal control. If both of these conditions are met, the overridden method writes the HTML string <H2>Your Message:, the contents of the literal control, and a closing </H2> tag to the Web Forms page.
[Visual Basic] Option Explicit Option Strict Imports System Imports System.Web Imports System.Web.UI Imports Microsoft.VisualBasic Namespace SimpleControlSamples Public Class InnerContent Inherits Control <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _ Protected Overrides Sub Render(output As HtmlTextWriter) If HasControls() And TypeOf Controls(0) Is LiteralControl Then output.Write("<H2>Your Message: " & CType(Controls(0), LiteralControl).Text & "</H2>") End If End Sub 'Render End Class 'InnerContent End Namespace 'SimpleControlSamples [C#] using System; using System.Web; using System.Web.UI; namespace SimpleControlSamples { public class InnerContent : Control { [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] protected override void Render(HtmlTextWriter output) { if ( (HasControls()) && (Controls[0] is LiteralControl) ) { output.Write("<H2>Your Message: " + ((LiteralControl) Controls[0]).Text + "</H2>"); } } } } [C++] #using <mscorlib.dll> #using <System.dll> #using <System.Web.dll> using namespace System; using namespace System::Web; using namespace System::Web::UI; public __gc class InnerContent : public Control { protected: [System::Security::Permissions::PermissionSet(System::Security::Permissions::SecurityAction::Demand, Name=S"FullTrust")] void Render(HtmlTextWriter* output) { if ( (HasControls()) && dynamic_cast<LiteralControl*>(Controls->Item[0]) ) { output->Write(S"<H2>Your Message: {0}</H2>", (dynamic_cast<LiteralControl*>(Controls->Item[0]))->Text); } } }; [JScript] import System; import System.Web; import System.Web.UI; import System.Security.Permissions; package SimpleControlSamples { public class InnerContent extends Control { protected override function Render(output : HtmlTextWriter) { var securityperm : SecurityPermission; securityperm = new SecurityPermission(SecurityPermissionFlag.SerializationFormatter); securityperm.Demand(); if ( (HasControls()) && (typeof(Controls[0]) == LiteralControl) ) { output.Write("<H2>Your Message: " + (LiteralControl(Controls[0])).Text + "</H2>"); } } } }
Requirements
Namespace: System.Web.UI
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
Assembly: System.Web (in System.Web.dll)
See Also
Control Members | System.Web.UI Namespace | Developing ASP.NET Server Controls | Page | TemplateControl | LiteralControl