C#鼠标拖动控件改变位置并绘制虚框

private Point downPoint;

private Rectangle downRectangle;

private Rectangle lastRectangle;

private void pictureBox1_MouseDown(object sender, MouseEventArgs e)

{

if (e.Button != MouseButtons.Left) return;

downPoint = e.Location;

downRectangle =

new Rectangle(0, 0, ((Control)sender).Width, pictureBox1.Height);

downRectangle.Offset(((Control)sender).PointToScreen(new Point(0, 0)));

ControlPaint.DrawReversibleFrame(

downRectangle, Color.White, FrameStyle.Thick);

lastRectangle = downRectangle;

}

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)

{

if (e.Button != MouseButtons.Left) return;

ControlPaint.DrawReversibleFrame(

lastRectangle, Color.White, FrameStyle.Thick);

Rectangle rectangle = downRectangle;

rectangle.Offset(e.X - downPoint.X, e.Y - downPoint.Y);

ControlPaint.DrawReversibleFrame(

rectangle, Color.White, FrameStyle.Thick);

lastRectangle = rectangle;

}

private void pictureBox1_MouseUp(object sender, MouseEventArgs e)

{

if (e.Button != MouseButtons.Left) return;

ControlPaint.DrawReversibleFrame(

lastRectangle, Color.White, FrameStyle.Thick);

pictureBox1.Location = new Point(

((Control)sender).Location.X + e.X - downPoint.X,

((Control)sender).Location.Y + e.Y - downPoint.Y);

}