Application.RemoveMessageFilter(IMessageFilter) Method

Definition

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

Removes a message filter from the message pump of the application.

public:
 static void RemoveMessageFilter(System::Windows::Forms::IMessageFilter ^ value);
public static void RemoveMessageFilter (System.Windows.Forms.IMessageFilter value);
static member RemoveMessageFilter : System.Windows.Forms.IMessageFilter -> unit
Public Shared Sub RemoveMessageFilter (value As IMessageFilter)

Parameters

value
IMessageFilter

The implementation of the IMessageFilter to remove from the application.

Examples

Before you can use a message filter, you must provide an implementation for the IMessageFilter interface. The following class creates a message filter called TestMessageFilter. This filter blocks all messages relating to the left mouse button.

// Creates a  message filter.
ref class TestMessageFilter: public IMessageFilter
{
public:
   [SecurityPermission(SecurityAction::LinkDemand, Flags = SecurityPermissionFlag::UnmanagedCode)]
   virtual bool PreFilterMessage( Message % m )
   {
      
      // Blocks all the messages relating to the left mouse button.
      if ( m.Msg >= 513 && m.Msg <= 515 )
      {
         Console::WriteLine( "Processing the messages : {0}", m.Msg );
         return true;
      }

      return false;
   }

};


// Creates a  message filter.
[SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
public class TestMessageFilter : IMessageFilter
{
    public bool PreFilterMessage(ref Message m)
    {
        // Blocks all the messages relating to the left mouse button.
        if (m.Msg >= 513 && m.Msg <= 515)
        {
            Console.WriteLine("Processing the messages : " + m.Msg);
            return true;
        }
        return false;
    }
}


' Creates a message filter.
<SecurityPermission(SecurityAction.LinkDemand, Flags := SecurityPermissionFlag.UnmanagedCode)> _
Public Class TestMessageFilter
    Implements IMessageFilter

    <SecurityPermission(SecurityAction.Demand)> _
    Public Function PreFilterMessage(ByRef m As System.Windows.Forms.Message) _
    As Boolean Implements IMessageFilter.PreFilterMessage
        ' Blocks all the messages relating to the left mouse button.
        If ((m.Msg >= 513) And (m.Msg <= 515)) Then
            Console.WriteLine("Processing the messages : " & m.Msg)
            Return True
        End If
        Return False
    End Function
End Class

Remarks

You can remove a message filter when you no longer want to capture Windows messages before they are dispatched.

Applies to

See also