直接绘制到 PictureBox

Question

我正在开发一个 屏幕共享应用程序 ，它不断运行循环并从套接字接收小帧。下一步是将它们绘制到 PictureBox 中。当然，我使用线程是因为我不想冻结 ui.

这是我的代码：

 Bitmap frame = byteArrayToImage(buff) as Bitmap;//a praticular bitmap im getting from a socket.
 Bitmap current =  (Bitmap)pictureBox1.Image;
 var graphics = Graphics.FromImage(current);
 graphics.DrawImage(frame, left, top);//left and top are two int variables of course.
 pictureBox1.Image = current;

但现在我收到一个错误：

Object is already in use elsewhere.

这一行var graphics = Graphics.FromImage(current);

试图Clone它，创建一个New Bitmap(current)。仍然没有成功。

Answer 1

Invalidate() 您的 PictureBox 以便它重新绘制自己：

Bitmap frame = byteArrayToImage(buff) as Bitmap;
using (var graphics = Graphics.FromImage(pictureBox1.Image))
{
    graphics.DrawImage(frame, left, top);
}
pictureBox1.Invalidate();

如果你需要它是线程安全的，那么：

pictureBox1.Invoke((MethodInvoker)delegate {
    Bitmap frame = byteArrayToImage(buff) as Bitmap;
    using (var graphics = Graphics.FromImage(pictureBox1.Image))
    {
        graphics.DrawImage(frame, left, top);
    }
    pictureBox1.Invalidate();
});

直接绘制到 PictureBox

Draw directly to PictureBox

c#

multithreading

picturebox

invoke