FindControl Method (String)
.NET Framework Class Library
Page..::.FindControl Method (String)

Searches the page naming container for a server control with the specified identifier.

Namespace:  System.Web.UI
Assembly:  System.Web (in System.Web.dll)
 Syntax
Visual Basic (Declaration) 
Public Overrides Function FindControl ( _
    id As String _
) As Control
Visual Basic (Usage) 
Dim instance As Page
Dim id As String
Dim returnValue As Control

returnValue = instance.FindControl(id)
C# 
public override Control FindControl(
    string id
)
Visual C++ 
public:
virtual Control^ FindControl(
    String^ id
) override
JScript 
public override function FindControl(
    id : String
) : 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 nullNothingnullptra null reference (Nothing in Visual Basic) if the specified control does not exist.
 Remarks

The FindControl method can be used to access a control whose ID is not available at design time. The method searches only the page's immediate, or top-level, container; it does not recursively search for controls in naming containers contained on the page. To access controls in a subordinate naming container, call the FindControl method of that container.
 Examples

The following code example demonstrates how to use the FindControl method to locate controls inside templates. In this example, two Repeater controls are defined; each shows a different way to catch the Click event of a LinkButton inside the repeater item template.

Visual Basic 
<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  Private Class RepeaterObject

    Private _string As String

    Public Sub New(ByVal label As String)
      _string = label
    End Sub

    Public Property RepeaterLabel() As String
      Get
        Return _string
      End Get
      Set(ByVal value As String)
        _string = value
      End Set
    End Property

  End Class


  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

    If (Not IsPostBack) Then

      Dim al As New ArrayList()
      al.Add(New RepeaterObject("foo1"))
      al.Add(New RepeaterObject("foo2"))
      al.Add(New RepeaterObject("foo3"))
      Repeater1.DataSource = al
      Repeater2.DataSource = al
      DataBind()
    End If

  End Sub


  ' This occurs for Repeater1 and originates from LinkButton onClick.
  Protected Sub OnMyCommand1(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.CommandEventArgs)
    Dim b As LinkButton = sender
    If Not (b Is Nothing) Then
      Dim c As Label = CType(b.Parent.FindControl("foo"), Label)
      If Not (c Is Nothing) Then
        c.Text = "text changed in handler"
        c.ForeColor = System.Drawing.Color.Green
      End If
    End If

  End Sub

  ' This occurs for Repeater2 and comes from the Repeater onItemCommand.
  Protected Sub OnMyCommand2(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.RepeaterCommandEventArgs)
    Dim l As Label = CType(e.Item.FindControl("foo"), Label)
    If Not (l Is Nothing) Then
      l.Text = "text changed in handler"
      l.ForeColor = System.Drawing.Color.Red
    End If
  End Sub

</script>

<html  >
<head runat="server">
    <title>Page FindControl Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <asp:Panel ID="Panel1" runat="server" >
        This repeater sample shows the bubbled event and FindControl when the repeater item OnCommand event occurs.<br />
        <asp:Repeater ID="Repeater1" runat="server">
            <ItemTemplate>
                <asp:Label runat="server" ID="foo" Text='<%#Eval("RepeaterLabel")%>' />&nbsp;
                <asp:LinkButton ID="LinkButton1" Text="Change" runat="server" OnCommand="OnMyCommand1" /> <br />
            </ItemTemplate>
        </asp:Repeater>
        <hr />

        This repeater shows the bubbled event and FindControl when the repeater OnItemCommand event occurs. <br />
        <asp:Repeater ID="Repeater2" runat="server" OnItemCommand="OnMyCommand2">
            <ItemTemplate>
                <asp:Label runat="server" ID="foo" Text='<%#Eval("RepeaterLabel")%>' />&nbsp;
                <asp:LinkButton ID="LinkButton2" Text="Change" runat="server" /> <br />
            </ItemTemplate>
        </asp:Repeater>
    </asp:Panel>

    </div>
    </form>
</body>
</html>
C# 
<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  private class RepeaterObject
  {
    private string _string;

    public RepeaterObject(string label)
    {
      _string = label;
    }

    public string RepeaterLabel
    {
      get { return _string; }
      set { _string = value; }
    }
  }

  protected void Page_Load()
  {
    if (!IsPostBack)
    {
      ArrayList al = new ArrayList();

      al.Add(new RepeaterObject("foo1"));
      al.Add(new RepeaterObject("foo2"));
      al.Add(new RepeaterObject("foo3"));
      Repeater1.DataSource = al;
      Repeater2.DataSource = al;
      DataBind();
    }
  }


  // This occurs for Repeater1 and originates from LinkButton onClick.
  protected void OnMyCommand1(object sender, CommandEventArgs e)
  {
    LinkButton b = sender as LinkButton;
    if (b != null)
    {
      Label c = (Label)b.Parent.FindControl("foo");
      if (c != null)
      {
        c.Text = "text changed in handler";
        c.ForeColor = System.Drawing.Color.Green;
      }
    }
  }

  // This occurs for Repeater2 and comes from the Repeater onItemCommand.
  protected void OnMyCommand2(object sender, RepeaterCommandEventArgs e)
  {
    Label l = (Label)e.Item.FindControl("foo");
    if (l != null)
    {
      l.Text = "text changed in handler";
      l.ForeColor = System.Drawing.Color.Red;
    }
  }
</script>

<html  >
<head runat="server">
    <title>Page FindControl Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

    <asp:Panel ID="Panel1" runat="server" >
        This repeater sample shows the bubbled event and FindControl when the repeater item OnCommand event occurs.<br />
        <asp:Repeater ID="Repeater1" runat="server">
            <ItemTemplate>
                <asp:Label runat="server" ID="foo" Text='<%#Eval("RepeaterLabel")%>' />&nbsp;
                <asp:LinkButton Text="Change" runat="server" OnCommand="OnMyCommand1" /> <br />
            </ItemTemplate>
        </asp:Repeater>
        <hr />

        This repeater shows the bubbled event and FindControl when the repeater OnItemCommand event occurs. <br />
        <asp:Repeater ID="Repeater2" runat="server" OnItemCommand="OnMyCommand2">
            <ItemTemplate>
                <asp:Label runat="server" ID="foo" Text='<%#Eval("RepeaterLabel")%>' />&nbsp;
                <asp:LinkButton Text="Change" runat="server" /> <br />
            </ItemTemplate>
        </asp:Repeater>
    </asp:Panel>

    </div>
    </form>
</body>
</html>
 Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
 Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0
 See Also

Reference

Page Class
Page Members
FindControl Overload
System.Web.UI Namespace
ID
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