第一种: Bitmap desktopBmp = new Bitmap(Screen.AllScreens[0].Bounds.Width, Screen.AllScreens[0].Bounds.Height); using (Graphics gBmp = Graphics.FromImage(desktopBmp)) { gBmp.CopyFromScreen(new Point(0, 0), new Point(0, 0), desktopBmp.Size); } this.BackgroundImage = desktopBmp; 第二种: private void button1_Click(object sender, EventArgs e) { 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); ScreenBody body = new ScreenBody(); body.BackgroundImage = img; body.Show(); } 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 ZhuoMianJieTu { public partial class ScreenBody : Form { public ScreenBody() { InitializeComponent(); } private Graphics MainPainter; //主画笔 private Pen pen; //就是笔咯 private bool isDowned; //判断鼠标是否按下 private bool RectReady; //矩形是否绘制完成 private Image baseImage; //基本图形(原来的画面) private Rectangle Rect; //就是要保存的矩形 private Point downPoint; //鼠标按下的点 int tmpx; int tmpy; private void ScreenBody_DoubleClick(object sender, EventArgs e) { if (((MouseEventArgs)e).Button == MouseButtons.Left && Rect.Contains(((MouseEventArgs)e).X, ((MouseEventArgs)e).Y)) { //保存的时候有很多种方法的......我这里只用了这种 Image memory = new Bitmap(Rect.Width, Rect.Height); Graphics g = Graphics.FromImage(memory); g.CopyFromScreen(Rect.X + 1, Rect.Y + 1, 0, 0, Rect.Size); Clipboard.SetImage(memory); this.Close(); } } private void ScreenBody_MouseDown(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { isDowned = true; if (RectReady == false) { Rect.X = e.X; Rect.Y = e.Y; downPoint = new Point(e.X, e.Y); } if (RectReady == true) { tmpx = e.X; tmpy = e.Y; } } if (e.Button == MouseButtons.Right) { if (RectReady != true) { this.Close(); return; } MainPainter.DrawImage(baseImage, 0, 0); RectReady = false; } } private void ScreenBody_MouseUp(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { isDowned = false; RectReady = true; } } private void ScreenBody_MouseMove(object sender, MouseEventArgs e) { if (RectReady == false) { if (isDowned == true) { Image New = DrawScreen((Image)baseImage.Clone(), e.X, e.Y); MainPainter.DrawImage(New, 0, 0); New.Dispose(); } } if (RectReady == true) { if (Rect.Contains(e.X, e.Y)) { //this.Cursor = Cursors.Hand; if (isDowned == true) { //和上一次的位置比较获取偏移量 Rect.X = Rect.X + e.X - tmpx; Rect.Y = Rect.Y + e.Y - tmpy; //记录现在的位置 tmpx = e.X; tmpy = e.Y; MoveRect((Image)baseImage.Clone(), Rect); } } } } private void ScreenBody_Load(object sender, EventArgs e) { this.WindowState = FormWindowState.Maximized; MainPainter = this.CreateGraphics(); pen = new Pen(Brushes.Blue); isDowned = false; baseImage = this.BackgroundImage; Rect = new Rectangle(); RectReady = false; } private void DrawRect(Graphics Painter, int Mouse_x, int Mouse_y) { int width = 0; int heigth = 0; if (Mouse_y < Rect.Y) { Rect.Y = Mouse_y; heigth = downPoint.Y - Mouse_y; } else { heigth = Mouse_y - downPoint.Y; } if (Mouse_x < Rect.X) { Rect.X = Mouse_x; width = downPoint.X - Mouse_x; } else { width = Mouse_x - downPoint.X; } Rect.Size = new Size(width, heigth); Painter.DrawRectangle(pen, Rect); } private Image DrawScreen(Image back, int Mouse_x, int Mouse_y) { Graphics Painter = Graphics.FromImage(back); DrawRect(Painter, Mouse_x, Mouse_y); return back; } private void MoveRect(Image image, Rectangle Rect) { Graphics Painter = Graphics.FromImage(image); Painter.DrawRectangle(pen, Rect.X, Rect.Y, Rect.Width, Rect.Height); //DrawRects(Painter); MainPainter.DrawImage(image, 0, 0); image.Dispose(); } } }