public void OnKeyDown(System.Windows.Input.KeyEventArgs e) { if (ImageSurface == null || !ImageSurface.Focused) { return; } switch (e.Key) { case Key.Escape: if (ImageSurface.IsDrawingZoomRect) { ImageSurface.IsDrawingZoomRect = false; ImageSurface.ZoomRect(false); ImageSurface.Invalidate(); e.Handled = true; } else if (IsFullScreen) { ToggleFullscreen(); ImageSurface.Invalidate(); e.Handled = true; } break; case Key.Left: if (ImageSurface.Focused) { ImageSurface.OnLeft(); e.Handled = true; } break; case Key.Right: if (ImageSurface.Focused) { ImageSurface.OnRight(); e.Handled = true; } break; case Key.Up: if (ImageSurface.Focused) { ImageSurface.OnUp(); e.Handled = true; } break; case Key.Down: if (ImageSurface.Focused) { ImageSurface.OnDown(); e.Handled = true; } break; case Key.Add: if (ImageSurface.Focused) { ImageSurface.Zoom(15f, true, true); } break; case Key.Subtract: if (ImageSurface.Focused) { ImageSurface.Zoom(-15f, true, true); } break; default: break; } }