Control.ID Property

Gets or sets the programmatic identifier assigned to the server control.

Namespace: System.Web.UI
Assembly: System.Web (in system.web.dll)

public virtual string ID { get; set; }
/** @property */
public String get_ID ()

/** @property */
public void set_ID (String value)

public function get ID () : String

public function set ID (value : String)

Not applicable.

Property Value

The programmatic identifier assigned to the control.

Setting this property on a server control provides you with programmatic access to the server control's properties, events, and methods. This property can be set by Web developers by declaring an ID attribute in the opening tag of an ASP.NET server control.

If this property is not specified for a server control, either declaratively or programmatically, you can obtain a reference to the control through its parent control's Controls property.


Only combinations of alphanumeric characters and the underscore character ( _ ) are valid values for this property. Including spaces or other invalid characters will cause an ASP.NET page parser error.

void Page_Init(object sender,EventArgs e)
   // Add a event Handler for 'Init'.
   myControl.Init += new System.EventHandler(Control_Init);

void Control_Init(object sender,EventArgs e)
  Response.Write("The ID of the object initially : " + myControl.ID);      
  // Change the ID property.
   Response.Write("<br />The changed ID : " + myControl.ID);

void Page_Init(Object sender,EventArgs e)
    // Add a event Handler for 'Init'.
    myControl.add_Init(new System.EventHandler(Control_Init));
} //Page_Init

void Control_Init(Object sender,EventArgs e)
    get_Response().Write("The ID of the object initially : " 
  + myControl.get_ID());
    // Change the ID property.
    get_Response().Write("<br />The changed ID : " + myControl.get_ID());
} //Control_Init

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0