利用Rectangle根据鼠标移动画框

 

public partial class Form4 : Form 
    { 
        private Point point=new Point(0,0); 
        private System.Drawing.Rectangle rectangle=new Rectangle(0,0,0,0); 
        private bool isdrawselect; 
        public Form4() 
        { 
            InitializeComponent(); 
        } 
        private void Form4_Load(object sender, EventArgs e) 
        { 
         
        } 
        private void Form4_MouseDown(object sender, MouseEventArgs e) 
        { 
            point = e.Location; 
            isdrawselect = true; 
        } 
        private void Form4_MouseMove(object sender, MouseEventArgs e) 
        { 
            if (isdrawselect) 
            { 
                rectangle.Height = Math.Abs(e.Y - point.Y); 
                rectangle.Width = Math.Abs(e.X - point.X) ; 
                rectangle.X = e.X > point.X ? point.X : e.X; 
                rectangle.Y = e.Y > point.Y ? point.Y : e.Y; 
                System.Drawing.Graphics gp = CreateGraphics(); 
                gp.Clear(BackColor); 
                gp.DrawRectangle(Pens.Red, rectangle); 
                label5.Text = "height=" + rectangle.Height; 
                label6.Text = "width=" + rectangle.Width; 
            } 
            label1.Text = "X=" + e.X; 
            label2.Text = "Y=" + e.Y; 
            label3.Text = "point.X="+point.X; 
            label4.Text = "point.Y="+point.Y; 
        } 
        private void Form4_MouseUp(object sender, MouseEventArgs e) 
        { 
            isdrawselect = false; 
        } 

    }