private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
bool ret;
uint pointId;
PointerInputType inputType = PointerInputType.PEN;
POINTER_PEN_INFO penInfo = new POINTER_PEN_INFO();
switch (msg)
{
case API.WM_POINTERENTER:
case API.WM_POINTERUPDATE:
case API.WM_POINTERDOWN:
case API.WM_POINTERUP:
case API.WM_POINTERLEAVE:
pointId = API.GET_POINTERID_WPARAM((uint)wParam.ToInt32());
ret = API.GetPointerType(pointId, ref inputType);
if (!ret)
{
break;
}
if (inputType == PointerInputType.PEN)
{
ret = API.GetPointerPenInfo(pointId, ref penInfo);
if (!ret)
{
break;
}
ProcessPenPoint(msg, penInfo,
API.GET_X_LPARAM((uint)lParam.ToInt32()),
API.GET_Y_LPARAM((uint)lParam.ToInt32()));
}
handled = true;
break;
default:
break;
}
return(IntPtr.Zero);
}
public static extern bool GetPointerPenInfo(uint pointerId, [In, Out] ref POINTER_PEN_INFO penInfo);
private void ProcessPenPoint(int msg, POINTER_PEN_INFO penInfo, uint x, uint y)
{
Point pt = this.PointFromScreen(new Point(x, y));
float pressure = penInfo.pressure;
pressure /= 1024;
StylusPoint sp = new StylusPoint(pt.X, pt.Y, pressure);
switch (msg)
{
case API.WM_POINTERENTER:
if ((penInfo.penFlags & PenFlags.ERASER) > 0 ||
(penInfo.penFlags & PenFlags.INVERTED) > 0)
{
inkCanvas1.EditingMode = InkCanvasEditingMode.EraseByStroke;
}
else
{
inkCanvas1.EditingMode = InkCanvasEditingMode.Ink;
}
break;
case API.WM_POINTERDOWN:
isDown = true;
if (inkCanvas1.EditingMode == InkCanvasEditingMode.Ink)
{
stroke = new Stroke(new StylusPointCollection(new StylusPoint[] { sp }), inkCanvas1.DefaultDrawingAttributes);
inkCanvas1.Strokes.Add(stroke);
}
else if (inkCanvas1.EditingMode == InkCanvasEditingMode.EraseByStroke)
{
points = new List <Point>();
points.Add(pt);
}
break;
case API.WM_POINTERUPDATE:
if (isDown)
{
if (inkCanvas1.EditingMode == InkCanvasEditingMode.Ink)
{
stroke.StylusPoints.Add(sp);
}
else if (inkCanvas1.EditingMode == InkCanvasEditingMode.EraseByStroke)
{
points.Add(pt);
StrokeCollection sc = inkCanvas1.Strokes.HitTest(points, inkCanvas1.EraserShape);
inkCanvas1.Strokes.Remove(sc);
}
}
break;
case API.WM_POINTERUP:
isDown = false;
if (inkCanvas1.EditingMode == InkCanvasEditingMode.Ink)
{
stroke.StylusPoints.Add(sp);
}
break;
}
}
