c#图像截取实例

本文实例讲述了c#图像截取的实现方法。分享给大家供大家参考。具体如下：

图像截取的相关代码如下：

private void button1_Click(object sender, EventArgs e)

{

Image pic = new Bitmap(this.Width, this.Height);

Graphics graphic = Graphics.FromImage(pic);

graphic.CopyFromScreen(new Point(this.Location.X, this.Location.Y), new Point(0, 0), new Size(this.Width, this.Height));

pic.Save(@”d:/test.jpeg”, ImageFormat.Jpeg);

graphic.Dispose();

}

[System.Runtime.InteropServices.DllImportAttribute(“gdi32.dll”)]

private static extern bool BitBlt(

IntPtr hdcDest, //目标设备的句柄

int nXDest, // 目标对象的左上角的X坐标

int nYDest, // 目标对象的左上角的X坐标

int nWidth, // 目标对象的矩形的宽度

int nHeight, // 目标对象的矩形的长度

IntPtr hdcSrc, // 源设备的句柄

int nXSrc, // 源对象的左上角的X坐标

int nYSrc, // 源对象的左上角的X坐标

System.Int32 dwRop // 光栅的操作值

);

[System.Runtime.InteropServices.DllImportAttribute(“gdi32.dll”)]

private static extern IntPtr CreateDC(

string lpszDriver, // 驱动名称

string lpszDevice, // 设备名称

string lpszOutput, // 无用，可以设定位”NULL”

IntPtr lpInitData // 任意的打印机数据

);

private void Form1_SizeChanged(object sender, EventArgs e)

{

}

private void button2_Click(object sender, EventArgs e)

{

this.Hide();

IntPtr dc1 = CreateDC(“DISPLAY”, null,

null, (IntPtr)null);

//创建显示器的DC

Graphics g1 = Graphics.FromHdc(dc1);

//由一个指定设备的句柄创建一个新的Graphics对象

Bitmap MyImage =

new Bitmap(Screen.PrimaryScreen.Bounds.Width,

Screen.PrimaryScreen.Bounds.Height, g1);

//根据屏幕大小创建一个与之相同大小的Bitmap对象

Graphics g2 = Graphics.FromImage(MyImage);

//获得屏幕的句柄

IntPtr dc3 = g1.GetHdc();

//获得位图的句柄

IntPtr dc2 = g2.GetHdc();

//把当前屏幕捕获到位图对象中

BitBlt(dc2, 0, 0, Screen.PrimaryScreen.Bounds.Width,

Screen.PrimaryScreen.Bounds.Height,

dc3, 0, 0, 13369376);

//把当前屏幕拷贝到位图中

g1.ReleaseHdc(dc3);

//释放屏幕句柄

g2.ReleaseHdc(dc2);

//释放位图句柄

Bitmap img = new Bitmap(MyImage, 800, 600);

//缩放图片到800*600

img.Save(“d:\\MyJpeg.jpg”, ImageFormat.Jpeg);

MessageBox.Show(“已经把当前屏幕保存到” +

“C:\\MyJpeg.jpg文件中！”);

this.Show();

}

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