Control.ControlCollection.Contains Method

This method enables you to determine whether a Control is a member of the collection before attempting to perform operations on the Control. You can use this method to confirm that a Control has been added to or is still a member of the collection.

The following code example removes a Control from the Control.ControlCollection of the derived class Panel if it is a member of the collection. The example requires that you have created a Panel, a Button, and at least one RadioButton control on a Form. The RadioButton controls are added to the Panel control, and the Panel control added to the Form. When the button is clicked, the radio button named removeButton is removed from the Control.ControlCollection.

    ' Remove the RadioButton control if it exists. 
    Private Sub RemoveButton_Click(ByVal sender As System.Object, _
		ByVal e As System.EventArgs) Handles RemoveButton.Click
        If Panel1.Controls.Contains(RemoveButton) Then
            Panel1.Controls.Remove(RemoveButton)
        End If 
    End Sub

.NET Framework

.NET Framework Client Profile

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.

Reference