您保持一个新的位图设置在PictureBox和previous位图是永远不会处理。一段时间后，系统运行短GDI处理和/或内存（运行你code，我消耗的存储器的一个演出下15秒）。

You keep setting a new bitmap to the picturebox, and the previous bitmap is never disposed. After a while, the system runs short of GDI handles and/or memory (running your code, I consumed one gig of memory in under 15 seconds).

您可以简单地重用现有的位图：

You can simply reuse your existing bitmap:

Rectangle bounds = Screen.GetBounds(Point.Empty);

Image bitmap = pictureBox1.Image ?? new Bitmap(bounds.Width, bounds.Height);

using (Graphics graphics = Graphics.FromImage(bitmap))
{
    graphics.CopyFromScreen(0, 0, 0, 0, new Size(bounds.Width, bounds.Height));

    if (pictureBox1.Image == null)
    {
        pictureBox1.Image = bitmap;
    }
    else
    {
        pictureBox1.Refresh();
    }

}

您也不必重新 pictureBox1.SizeMode 在每次迭代。

You also don't have to reset pictureBox1.SizeMode on each iteration.

另外，您也可以手动处置previous位图：

Alternatively, you can dispose the previous bitmap manually:

Rectangle bounds = Screen.GetBounds(Point.Empty);
Bitmap bitmap = new Bitmap(bounds.Width, bounds.Height);
using (Graphics graphics = Graphics.FromImage(bitmap))
{
    graphics.CopyFromScreen(0, 0, 0, 0, new Size(bounds.Width, bounds.Height));

    using (Image prev_bitmap = pictureBox1.Image)
    {
        pictureBox1.Image = bitmap;
    }
}