protected override void OnRefresh()
{
RotaryKnob rotary = Visual as RotaryKnob;
if (rotary != null)
{
_imageRect.Width = rotary.Width;
_imageRect.Height = rotary.Height;
_image = ConfigManager.ImageManager.LoadImage(rotary.KnobImage);
_brush = new ImageBrush(_image);
_center = new Point(rotary.Width / 2d, rotary.Height / 2d);
}
else
{
_image = null;
_brush = null;
}
}
protected override void OnRender(System.Windows.Media.DrawingContext drawingContext)
{
RotaryKnob rotary = Visual as RotaryKnob;
if (rotary != null)
{
drawingContext.PushTransform(new RotateTransform(rotary.KnobRotation, _center.X, _center.Y));
drawingContext.DrawImage(_image, _imageRect);
if (rotary.VisualizeDragging)
{
double length = (rotary.DragPoint - _center).Length;
drawingContext.DrawLine(HeadingPen, _center, _center + new Vector(0d, -length));
}
drawingContext.Pop();
if (rotary.VisualizeDragging)
{
drawingContext.DrawLine(DragPen, _center, rotary.DragPoint);
}
}
}