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Control.FindControl Method (String)

Searches the current naming container for a server control with the specified id parameter.

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

'Declaration
Public Overridable Function FindControl ( _
	id As String _
) As Control

Parameters

id
Type: System.String

The identifier for the control to be found.

Return Value

Type: System.Web.UI.Control
The specified control, or Nothing if the specified control does not exist.

Use FindControl to access a control from a function in a code-behind page, to access a control that is inside another container, or in other circumstances where the target control is not directly accessible to the caller. This method will find a control only if the control is directly contained by the specified container; that is, the method does not search throughout a hierarchy of controls within controls. For information about how to find a control when you do not know its immediate container, see How to: Access Server Controls by ID.

TopicLocation
How to: Reference ASP.NET Master Page ContentBuilding ASP .NET Web Applications
How to: Reference ASP.NET Master Page ContentBuilding ASP .NET Web Applications

The following example defines a Button1_Click event handler. When invoked, this handler uses the FindControl method to locate a control with an ID property of TextBox2 on the containing page. If the control is found, its parent is determined using the Parent property and the parent control's ID is written to the page. If TextBox2 is not found, "Control Not Found" is written to the page.

Security noteSecurity Note

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.


   Private Sub Button1_Click(sender As Object, MyEventArgs As EventArgs)
   ' Find control on page.
   Dim myControl1 As Control = FindControl("TextBox2")
   If (Not myControl1 Is Nothing)
      ' Get control's parent.
      Dim myControl2 As Control = myControl1.Parent
      Response.Write("Parent of the text box is : " & myControl2.ID)
   Else
      Response.Write("Control not found.....")
   End If
   End Sub

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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