private void UnregisterFilter()
{
if (_filter != null)
{
Application.RemoveMessageFilter(_filter);
_filter = null;
}
}
private void RegisterFilter()
{
if (_filter == null)
{
// Check that caller has permission to access unmanaged code
new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Assert();
try
{
_filter = new SeparatorMessageFilter(this);
Application.AddMessageFilter(_filter);
}
finally
{
// Always revert the assertion made above
CodeAccessPermission.RevertAssert();
}
}
}