C# 屏幕截图

C# 屏幕截图
c#实现屏幕截图
Graphics 类的CopyFromScreen方法可以拿到整个屏幕的截图，屏幕截图的实现主要就是用到了他

思路是首先将整个屏幕的图像截取下来，然后作为一个窗体的背景显示给用户，由用户选择要截取的区域
后，保存图片就可以了

复制代码

public partial class Form2 : Form
{
private bool down = false;
private Point firstPoint;
private Pen p = new Pen(Color.Red);
private Graphics gra;
private Rectangle rectangle;//存储用户截取的矩形
public Form2()
{
InitializeComponent();
}

    private void Form2_Load(object sender, EventArgs e){Image img = new Bitmap(Screen.AllScreens[0].Bounds.Width, Screen.AllScreens[0].Bounds.Height);//创建一个和屏幕同样大小的图像Graphics g = Graphics.FromImage(img);//绘制这个图像

//将屏幕绘制到此图像，第一，二个Point是屏幕要截取的左上角的坐标和绘制到图像的左上角的坐标（哪个是哪个就忘了）
g.CopyFromScreen(new Point(0, 0), new Point(0, 0), Screen.AllScreens[0].Bounds.Size);
this.BackgroundImage = img;
this.FormBorderStyle = FormBorderStyle.None;
this.Bounds = Screen.PrimaryScreen.Bounds;
gra = this.CreateGraphics();//主要为了用户截取方便
}

    private void Form2_MouseDown(object sender, MouseEventArgs e){if (e.Button == MouseButtons.Left){down = true;firstPoint = e.Location;}}private void Form2_MouseUp(object sender, MouseEventArgs e){if (e.Button == MouseButtons.Left){down = false;}if (e.Button == MouseButtons.Middle){Application.Exit();}}private void Form2_MouseMove(object sender, MouseEventArgs e){if (down){gra.DrawImage(this.BackgroundImage, 0, 0);rectangle = new Rectangle(Math.Min(firstPoint.X, e.X), Math.Min(e.Y, firstPoint.Y), Math.Abs(e.X - firstPoint.X), Math.Abs(e.Y - firstPoint.Y));gra.DrawRectangle(p, rectangle);}}private void Form2_DoubleClick(object sender, EventArgs e){if (rectangle.Width != 0 && rectangle.Height != 0){gra.DrawImage(this.BackgroundImage, 0, 0);Image im = new Bitmap(rectangle.Width, rectangle.Height);Graphics g = Graphics.FromImage(im);g.CopyFromScreen(rectangle.Location, new Point(0, 0), rectangle.Size);if (((MouseEventArgs)e).Button == MouseButtons.Left){Clipboard.SetImage(im);MessageBox.Show("图像已经复制到剪切板！","复制成功");Application.Exit();}if (((MouseEventArgs)e).Button == MouseButtons.Right){if (saveFileDialog1.ShowDialog() == DialogResult.OK){im.Save(saveFileDialog1.FileName);MessageBox.Show("图像已经保存到本地！","保存成功");Application.Exit();}}}}
}