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:
public Form1()
{
InitializeComponent();
}
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();
}
希望本文所述对大家的C#程序设计有所帮助。