posted on Saturday, October 02, 2004 1:55 PM by taylorza

CWaitCursor for .NET

Being mostly a middle tier type I have not done much front end UI stuff for quite sometime. But lately I have been doing some Windows Forms development and I have been making extensive use of the following piece of code that I developed years ago.

class CursorManager : IDisposable
{
  private bool _disposed = false;
  private Control _owner;
  private Cursor _prevCursor;
  public CursorManager(Cursor cursor) : this(null, cursor)
  {
  }

  public CursorManager(Control owner, Cursor cursor)
  {
    _owner = owner;
    if ( _owner != null )
    {
      _prevCursor = _owner.Cursor;
      _owner.Cursor = cursor;
    }
    else
    {
      _prevCursor = Cursor.Current;
      Cursor.Current = cursor;
    }
  }

  ~CursorManager()
  {
    Dispose();
  }

  public void Dispose()
  {
    if (!_disposed)
    {
      if ( _owner != null )
        _owner.Cursor = _prevCursor;
      else
        Cursor.Current = _prevCursor;

      _disposed = true;
    }

    GC.SuppressFinalize(this);
  }
}

as elegant as the C++ solution. The C# using statement brings some elegance to this technique, while the current VB.NET syntax is not quite so sleek the VB.NET 2.0 will provide the same elegance as the C# syntax.

C#

using (new CursorManager(this, Cursors.WaitCursor))
{
  DoLongOperation();
}

VB.NET

Dim waitCursor As CursorManager
Try
  waitCursor = New CursorManager(Me, Cursors.WaitCursor)
  DoLongOperation()
Finally
  If Not waitCursor Is Nothing Then waitCursor.Dispose()
End Try

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