1、控制器运行一个Process进程，等待不等待的问题

        public static async void Execute(string para, string ffmpegPath, string timestr, string Id, string targetUrl)
        {
           await Task.Run(() =>
            {
                CreTimeStr = timestr;
                rowId = Id;
                compPath = targetUrl;
                Process p = new Process();
                p.StartInfo.FileName = ffmpegPath;
                p.StartInfo.Arguments = para;  //执行参数
                p.StartInfo.UseShellExecute = false;
                p.StartInfo.RedirectStandardInput = true;
                p.StartInfo.RedirectStandardOutput = true;
                p.StartInfo.RedirectStandardError = true;//把外部程序错误输出写到StandardError流中
                p.ErrorDataReceived += new DataReceivedEventHandler(p_ErrorDataReceived);
                p.OutputDataReceived += new DataReceivedEventHandler(p_OutputDataReceived);
                using (p)
                {
                    p.Start();
                    p.BeginErrorReadLine();//开始异步读取
                    p.WaitForExit();//阻塞等待进程结束
                    p.Close();//关闭进程
                }
            });
        }