c# - 截图并在表格中显示

Question

我尝试像描述的那样创建屏幕截图 here :

private Graphics takeScreenshot()
{
    //Create a new bitmap.
    var bmpScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
                                   Screen.PrimaryScreen.Bounds.Height,
                                   System.Drawing.Imaging.PixelFormat.Format32bppArgb);

    // Create a graphics object from the bitmap.
    var gfxScreenshot = Graphics.FromImage(bmpScreenshot);

    // Take the screenshot from the upper left corner to the right bottom corner.
    gfxScreenshot.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                                Screen.PrimaryScreen.Bounds.Y,
                                0,
                                0,
                                Screen.PrimaryScreen.Bounds.Size,
                                CopyPixelOperation.SourceCopy);

    return gfxScreenshot;
}

拍摄后如何在我的表格中显示？我试图在 pictureBox 中显示它:

Graphics screenshot = takeScreenshot();
pictureBox1.Image = screenshot;

但是我得到:

Severity Code Description Project File Line Suppression State Error CS0029 Cannot implicitly convert type 'System.Drawing.Graphics' to 'System.Drawing.Image' SRAT C:\Users\Edd\documents\visual studio 2017\Projects\SRAT\SRAT\Form1.cs 20 Active

和this answer说不可能转换它

Answer 1

Graphics 对象是一种图像包装器，可让您在图像上绘图。它们通常是临时的，实际上并不拥有您正在绘制的像素。

在您的情况下，gfxScreenshot 只是提供绘制到 bmpScreenshot 上的能力，这是图像实际存在于内存中的位置。

你应该扔掉 Graphics 并返回 Bitmap:

private Bitmap TakeScreenshot()
{
    //Create a new bitmap.
    var bmpScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
                                   Screen.PrimaryScreen.Bounds.Height,
                                   System.Drawing.Imaging.PixelFormat.Format32bppArgb);

    // Create a graphics object from the bitmap.
    using (var gfxScreenshot = Graphics.FromImage(bmpScreenshot))
    {    
        // Take the screenshot from the upper left corner to the right bottom corner.
        gfxScreenshot.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                                Screen.PrimaryScreen.Bounds.Y,
                                0,
                                0,
                                Screen.PrimaryScreen.Bounds.Size,
                                CopyPixelOperation.SourceCopy);    
    }

    return bmpScreenshot;
}

然后您可以将位图分配给 PictureBox:

Bitmap screenshot = TakeScreenshot();
pictureBox1.Image = screenshot;