Szerkesztés

Megosztás a következőn keresztül:

Control.ControlCollection.Contains(Control) Method

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll

Determines whether the specified control is a member of the collection.

public:
 bool Contains(System::Windows::Forms::Control ^ control);
public bool Contains (System.Windows.Forms.Control control);
public bool Contains (System.Windows.Forms.Control? control);
member this.Contains : System.Windows.Forms.Control -> bool
Public Function Contains (control As Control) As Boolean

Parameters

control
Control

The Control to locate in the collection.

Returns

Boolean

true if the Control is a member of the collection; otherwise, false.

Examples

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:
   void removeButton_Click( Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      if ( panel1->Controls->Contains( removeButton ) )
      {
         panel1->Controls->Remove( removeButton );
      }
   }

// Remove the RadioButton control if it exists.
private void removeButton_Click(object sender, System.EventArgs e)
{
   if(panel1.Controls.Contains(removeButton))
   {
      panel1.Controls.Remove(removeButton);
   }
}

' 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

Remarks

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.

Applies to

See also