c# - 对象当前正在别处使用 - 当 image.save

Question

使用以下代码，我们得到错误“对象当前正在别处使用”

private void CaptureDone(System.Drawing.Bitmap e)
        {
            try
            {
                this.pictureBox.Image = e;
                 if (isSending)
                    ThreadPool.QueueUserWorkItem(new WaitCallback(SendVideoBuffer), pictureBox.Image);
            }
            catch (Exception) { }
        }

     void SendVideoBuffer(object bufferIn)
            {
    TcpClient tcp = new TcpClient(ConfigurationSettings.AppSettings[0].ToString(), 6000);
                           NetworkStream ns = tcp.GetStream();
                           if (ns != null)
                           {
                               System.Drawing.Image buffer = (System.Drawing.Image)bufferIn;
                               buffer.Save(ns, System.Drawing.Imaging.ImageFormat.Jpeg);// error comes here
                               ns.Close();
                               tcp.Close();
                            }
           }

请给点建议。

Answer 1

GDI+ 图像不是线程安全的，您需要获取对象上的锁。

void SendVideoBuffer(object bufferIn) 
    { 

 var tcp = new TcpClient(ConfigurationSettings.AppSettings[0].ToString(), 6000); 
                   var ns = tcp.GetStream(); 
                   if (ns != null) 
                   { 
                       var buffer = (System.Drawing.Image)bufferIn;
                       lock(buffer) 
                            buffer.Save(ns, System.Drawing.Imaging.ImageFormat.Jpeg);
                       ns.Close(); 
                       tcp.Close(); 
        }
}