C# 怎么获取剪切板里的图片

Form1窗体//截屏按钮   
private void tsb_Screenshots_Click(object sender, EventArgs e)
        {
            
                Form_Cutpic newCapture = new Form_Cutpic();
                Image img = new Bitmap(Screen.AllScreens[0].Bounds.Width, Screen.AllScreens[0].Bounds.Height);
                Graphics g = Graphics.FromImage(img);
                g.CopyFromScreen(new Point(0, 0), new Point(0, 0), Screen.AllScreens[0].Bounds.Size);
                newCapture.BackgroundImage = img;
                newCapture.Show();
                rtb_sent.Paste();     //这里粘贴出来的是上一次次复制的内容~不是这次复制的~，理论上应该这次复制的会把上次复制的内容的覆盖啊~？为什么会这样
            //this.rtb_sent.Paste(DataFormats.GetFormat(DataFormats.Bitmap)); 
            
         }
另一个（截图）窗体Form2
        //双击鼠标左键时，保存图片
        private void Form_Cutpic_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left && CatchFinished)
            {
                if (CatchRect.Contains(new Point(e.X, e.Y)))
                {
                    Bitmap CatchedBmp = new Bitmap(CatchRect.Width, CatchRect.Height);//新建一个于矩形等大的空白图片
                    Graphics g = Graphics.FromImage(CatchedBmp);
                    g.DrawImage(originBmp, new Rectangle(0, 0, CatchRect.Width, CatchRect.Height), CatchRect, GraphicsUnit.Pixel);
                    //把orginBmp中的指定部分按照指定大小画在画板上
                    Clipboard.SetImage(CatchedBmp);//将图片保存到剪贴板
                    //ATAQQaClient.Form_Message.[color=#808000]rtb_sent.Paste();——可以在这里直接把图片传到另一个窗体空间上吗？[/color]                    
                    CatchedBmp.Save(@"C:\Documents and Settings\Administrator\My Documents\My Pictures\my.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
                    g.Dispose();
                    CatchFinished = false;
                    this.BackgroundImage = originBmp;
                    CatchedBmp.Dispose();
                    this.DialogResult = DialogResult.OK;
                    this.Close();
                }
            }
我在做截图~截图窗体所有的代码~
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace ATAQQaClient
{
    public partial class Form_Cutpic : Form
    {
        private Point DownPoint = Point.Empty;//记录鼠标按下坐标，用来确定绘图起点
        private bool CatchFinished = false;//用来表示是否截图完成
        private bool CatchStart = false;//表示截图开始
        private Bitmap originBmp;//用来保存原始图像
        private Rectangle CatchRect;//用来保存截图的矩形        public Form_Cutpic()
        {
            InitializeComponent();
        }        private void Form_Cutpic_Load(object sender, EventArgs e)
        {
            this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint, true);
            this.UpdateStyles();
            //以上两句是为了设置控件样式为双缓冲，这可以有效减少图片闪烁的问题
            originBmp = new Bitmap(this.BackgroundImage);//BackgroundImage为全屏图片，我们另用变量来保存全屏图片        }        //单击鼠标右键退出截屏操作
        private void Form_Cutpic_MouseClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                this.DialogResult = DialogResult.OK;
                this.Close();
            }
            lbl_Screenshots.Visible = false;
        }        //按下鼠标时开始捕获
        private void Form_Cutpic_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (!CatchStart)
                {//如果捕捉没有开始
                    CatchStart = true;
                    DownPoint = new Point(e.X, e.Y);//保存鼠标按下坐标
                }
            }
        }        //移动鼠标时，改变截屏区域
        private void Form_Cutpic_MouseMove(object sender, MouseEventArgs e)
        {  
                lbl_Screenshots.Visible = true;
                if (CatchStart)
                {//如果捕捉开始
                    
                    Bitmap destBmp = (Bitmap)originBmp.Clone();//新建一个图片对象，并让它与原始图片相同
                    Point newPoint = new Point(DownPoint.X, DownPoint.Y);//获取鼠标的坐标
                    Graphics g = Graphics.FromImage(destBmp);//在刚才新建的图片上新建一个画板
                    Pen p = new Pen(Color.Blue, 1);
                    int width = Math.Abs(e.X - DownPoint.X), height = Math.Abs(e.Y - DownPoint.Y);//获取矩形的长和宽
                    if (e.X < DownPoint.X)
                    {
                        newPoint.X = e.X;
                    }
                    if (e.Y < DownPoint.Y)
                    {
                        newPoint.Y = e.Y;
                    }
                    CatchRect = new Rectangle(newPoint, new Size(width, height));//保存矩形                    lbl_Screenshots.Text = "矩形大小" + width.ToString() + "*" + height.ToString() + "\n" + "\n" + "快速双击完成截图";//显示矩形的大小
                    lbl_Screenshots.Location = new Point(DownPoint.X, DownPoint.Y - 37); //lbl控件位置设置                    g.DrawRectangle(p, CatchRect);//将矩形画在这个画板上
                    g.Dispose();//释放目前的这个画板
                    p.Dispose();
                    Graphics g1 = this.CreateGraphics();//重新新建一个Graphics类
                    //如果之前那个画板不释放，而直接g=this.CreateGraphics()这样的话无法释放掉第一次创建的g,因为只是把地址转到新的g了．如同string一样
                    g1 = this.CreateGraphics();//在整个全屏窗体上新建画板
                    g1.DrawImage(destBmp, new Point(0, 0));//将刚才所画的图片画到这个窗体上
                    //这个也可以属于二次缓冲技术，如果直接将矩形画在窗体上，会造成图片抖动并且会有无数个矩形．
                    g1.Dispose();
                    destBmp.Dispose();//要及时释放，不然内存将会被大量消耗
                
            }        }        //松开鼠标时，确定最终的截屏区域
        private void Form_Cutpic_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (CatchStart)
                {
                    CatchStart = false;
                    CatchFinished = true;
                }
            }        }        //双击鼠标左键时，保存图片
        private void Form_Cutpic_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left && CatchFinished)
            {
                if (CatchRect.Contains(new Point(e.X, e.Y)))
                {
                    Bitmap CatchedBmp = new Bitmap(CatchRect.Width, CatchRect.Height);//新建一个于矩形等大的空白图片
                    Graphics g = Graphics.FromImage(CatchedBmp);
                    g.DrawImage(originBmp, new Rectangle(0, 0, CatchRect.Width, CatchRect.Height), CatchRect, GraphicsUnit.Pixel);
                    //把orginBmp中的指定部分按照指定大小画在画板上
                    Clipboard.SetImage(CatchedBmp);//将图片保存到剪贴板
                    //ATAQQaClient.Form_Message.rtb_sent.Paste();
                    
                    CatchedBmp.Save(@"C:\Documents and Settings\Administrator\My Documents\My Pictures\my.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
                    g.Dispose();
                    CatchFinished = false;
                    this.BackgroundImage = originBmp;
                    CatchedBmp.Dispose();
                    this.DialogResult = DialogResult.OK;
                    this.Close();
                }
            }        }       
           }
}