c# winfrom鼠标圈选矩形框

//鼠标圈选框变量 bool MouseIsDown = false; Rectangle MouseRect = Rectangle.Empty; private void form_drawGraph_Engross_MouseMove(object sender, MouseEventArgs e) { if (MouseIsDown) ResizeToRectangle(e.Location); } private void form_drawGraph_Engross_MouseUp(object sender, MouseEventArgs e) { //鼠标圈选框 this.Capture = false; Cursor.Clip = Rectangle.Empty; MouseIsDown = false; DrawRectangle(); MouseRect = Rectangle.Empty; } #region 鼠标圈选矩形 private void ResizeToRectangle(Point p) { DrawRectangle(); MouseRect.Width = p.X - MouseRect.Left; MouseRect.Height = p.Y - MouseRect.Top; DrawRectangle(); } private void DrawRectangle() { R