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);
}
本文来自Delphi之窗，原文地址：http://www.52delphi.com/