Page.FindControl(String) Method Definition Parameters Returns Examples Examples of ASP.NET C# page Examples of ASP.NET VB page Remarks Applies to See also Sources and References
Page.FindControl(String) Method
Definition
Namespace:System.Web.UIAssembly:
System.Web.dll
Searches the page naming container for a server control with the specified identifier.
Public Overrides Function FindControl (id As String) As Control
Parameters
idString
The identifier for the control to be found.
Returns
Control
The specified control, or null if the specified control does not exist.
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.
Examples of ASP.NET C# page
Examples of ASP.NET C# page
ASP.NET Code Input:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head runat="server">
<title>Sample Page</title>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<%@ Page Language="C#" %>
<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("RepeaterObject1"));
al.Add(new RepeaterObject("RepeaterObject2"));
al.Add(new RepeaterObject("RepeaterObject3"));
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("Label1");
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("Label1");
if (l != null)
{
l.Text = "text changed in handler";
l.ForeColor = System.Drawing.Color.Red;
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>Page FindControl Example</h3>
<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="Label1" Text='<%#Eval("RepeaterLabel")%>' />
<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="Label1" Text='<%#Eval("RepeaterLabel")%>' />
<asp:LinkButton Text="Change" runat="server" /> <br />
</ItemTemplate>
</asp:Repeater>
</asp:Panel>
</div>
</form>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head runat="server">
<title>Sample Page</title>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<%@ Page Language="vb" %>
<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("RepeaterObject1"))
al.Add(New RepeaterObject("RepeaterObject2"))
al.Add(New RepeaterObject("RepeaterObject3"))
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("Label1"), 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("Label1"), Label)
If Not (l Is Nothing) Then
l.Text = "text changed in handler"
l.ForeColor = System.Drawing.Color.Red
End If
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>Page FindControl Example</h3>
<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="Label1" Text='<%#Eval("RepeaterLabel")%>' />
<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="Label1" Text='<%#Eval("RepeaterLabel")%>' />
<asp:LinkButton Text="Change" runat="server" /> <br />
</ItemTemplate>
</asp:Repeater>
</asp:Panel>
</div>
</form>
</body>
</html>
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.