void MyRectangleDc(Point pt1, Point pt2)
{
Apis.MoveToEx(hdc, pt1.X, pt1.Y, IntPtr.Zero);
//Apis.LineTo(hdc, pt2.X, pt2.Y);
int left, top, right, bottom;
left = pt1.X;
top = pt1.Y;
right = pt2.X;
bottom = pt2.Y;
Apis.Rectangle(hdc, left, top, right, bottom);
}
protected override void OnMouseDown(System.Windows.Forms.MouseEventArgs e)
{
base.OnMouseDown(e);
if (!isStart)
{
isStart = true;
current = new Point(e.X, e.Y);
temp = new Point(e.X, e.Y);
hdc = Apis.GetDC(this.Handle);
Apis.SetROP2(hdc, R2.R2_NOTXORPEN);
}
else
{
MyRectangle(current, temp);
MyRectangle(current, new Point(e.X, e.Y));
Apis.ReleaseDC(this.Handle, hdc);
}
}