C#屏幕截图

今天通过C#来实现一个简单的屏幕截图功能。实现思路，获取鼠标按下去的位置和鼠标左键释放的位置，计算这个区域的宽度和高度。然后通过 Graphics.CopyFromScreen 方法便可以获取到屏幕截图了。

下面通过C#+WPF来实现这个功能，代码如下：

XAML:

<Window x:Class="WPFCaptureScreenShot.CaptureWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="CaptureWindow"

        AllowsTransparency="True"

        WindowStyle="None"

        Background="Black"

        Opacity="0.1"

        WindowState="Maximized"

        MouseDown="CaptureWindow_MouseDown"

        MouseMove="CaptureWindow_MouseMove">

    <Canvas x:Name="CaptureCanvas">

    </Canvas>

</Window>

    public partial class CaptureWindow : Window

    {

        private double x;

        private double y;

        private double width;

        private double height;

        private bool isMouseDown = false;

        public CaptureWindow()

        {

            InitializeComponent();

        }

        private void CaptureWindow_MouseDown(object sender, MouseButtonEventArgs e)

        {

            isMouseDown = true;

            x = e.GetPosition(null).X;

            y = e.GetPosition(null).Y;

        }

        private void CaptureWindow_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)

        {

            if(isMouseDown)

            {

                // 1. 通过一个矩形来表示目前截图区域

                System.Windows.Shapes.Rectangle rect = new System.Windows.Shapes.Rectangle();

                double dx = e.GetPosition(null).X;

                double dy = e.GetPosition(null).Y;

                double rectWidth = Math.Abs(dx - x);

                double rectHeight = Math.Abs(dy - y);

                SolidColorBrush brush = new SolidColorBrush(Colors.White);

                rect.Width = rectWidth;

                rect.Height = rectHeight;

                rect.Fill = brush;

                rect.Stroke = brush;

                rect.StrokeThickness = ;

                if (dx < x)

                {

                    Canvas.SetLeft(rect, dx);

                    Canvas.SetTop(rect, dy);

                }

                else

                {

                    Canvas.SetLeft(rect, x);

                    Canvas.SetTop(rect, y);

                }

                CaptureCanvas.Children.Clear();

                CaptureCanvas.Children.Add(rect);

                if(e.LeftButton == MouseButtonState.Released)

                {

                    CaptureCanvas.Children.Clear();

                    // 2. 获得当前截图区域

                    width = Math.Abs(e.GetPosition(null).X - x);

                    height = Math.Abs(e.GetPosition(null).Y - y);

                    if(e.GetPosition(null).X > x)

                    {

                        CaptureScreen(x, y, width, height);

                    }

                    else

                    {

                        CaptureScreen(e.GetPosition(null).X, e.GetPosition(null).Y, width, height);

                    }

                    isMouseDown = false;

                    x = 0.0;

                    y = 0.0;

                    this.Close();

                }

            }

        }

        private void CaptureScreen(double x, double y, double width, double height)

        {

            int ix = Convert.ToInt32(x);

            int iy = Convert.ToInt32(y);

            int iw = Convert.ToInt32(width);

            int ih = Convert.ToInt32(height);

            System.Drawing.Bitmap bitmap = new Bitmap(iw, ih);

            using(System.Drawing.Graphics graphics = Graphics.FromImage(bitmap))

            {

                graphics.CopyFromScreen(ix, iy, , , new System.Drawing.Size(iw, ih));

                SaveFileDialog dialog = new SaveFileDialog();

                dialog.Filter = "Png Files|*.png";

                if (dialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)

                {

                    bitmap.Save(dialog.FileName, ImageFormat.Png);

                }

            }

        }

运行效果：

源代码可以点击这里下载。
如果你有其他方式实现，欢迎与我分享。如果对代码有疑问，可以在评论中指出。感谢阅读。