topmost window form steal focus

Hi everyone, I develop a window form application that shows message like msn alert at the right corner of desktop. I set form's topmost property to true but it steals other application's focus while I work on them. I don't want application steal the focus that is annoying. How can I solve this problem . Any suggestion?

Best regards.

From stackoverflow

• Override the Form's CreateParams and ShowWithoutActivation properties, like this:

  protected override CreateParams CreateParams
  {
    get
    {
      CreateParams baseParams = base.CreateParams;
  
      // WS_EX_NOACTIVATE = 0x08000000,
      // WS_EX_TOOLWINDOW = 0x00000080,
      baseParams.ExStyle |= ( int )( 
        Win32.ExtendedWindowStyles.WS_EX_NOACTIVATE | 
        Win32.ExtendedWindowStyles.WS_EX_TOOLWINDOW );
  
      return baseParams;
    }
  }
  
  protected override bool ShowWithoutActivation
  {
    get { return true; }
  }