C#Process执行批处理后如何获取返回值？

代码如下   
p.StartInfo = new System.Diagnostics.ProcessStartInfo(path, pwd);
 p.Start();
其中path是个BAT的路径！
我想要得到执行后的返回值来判断批处理运行期间是否错误？
请问如何做呢？
批处理程序内容如下:
@echo off
for /f "delims=" %%a in (PCList.config) do net use \\%%a\ipc$ /delete
for /f "delims=" %%a in (PCList.config) do net use \\%%a\ipc$ %1 /user:administrator
pause

// Define the namespaces used by this sample.
using System;
using System.Text;
using System.Globalization;
using System.IO;
using System.Diagnostics;
using System.Threading;
using System.ComponentModel;
namespace ProcessAsyncStreamSamples
{
    class ProcessNetStreamRedirection
    {
        // Define static variables shared by class methods.
        private static StreamWriter streamError =null;
        private static String netErrorFile = "";
        private static StringBuilder netOutput = null;
        private static bool errorRedirect = false;
        private static bool errorsWritten = false;
        public static void RedirectNetCommandStreams()
        {
            String netArguments;
            Process netProcess;
            // Get the input computer name.
            Console.WriteLine("Enter the computer name for the net view command:");
            netArguments = Console.ReadLine().ToUpper(CultureInfo.InvariantCulture);
            if (String.IsNullOrEmpty(netArguments))
            {
                // Default to the help command if there is not an input argument.
                netArguments = "/?";
            }
            // Check if errors should be redirected to a file.
            errorsWritten = false;
            Console.WriteLine("Enter a fully qualified path to an error log file");
            Console.WriteLine("  or just press Enter to write errors to console:");
            netErrorFile = Console.ReadLine().ToUpper(CultureInfo.InvariantCulture);
            if (!String.IsNullOrEmpty(netErrorFile))
            {
                errorRedirect = true;
            }
            // Note that at this point, netArguments and netErrorFile
            // are set with user input.  If the user did not specify
            // an error file, then errorRedirect is set to false.
            // Initialize the process and its StartInfo properties.
            netProcess = new Process();
            netProcess.StartInfo.FileName = "Net.exe";
            // Build the net command argument list.
            netProcess.StartInfo.Arguments = String.Format("view {0}",
                netArguments);
            // Set UseShellExecute to false for redirection.
            netProcess.StartInfo.UseShellExecute = false;
            // Redirect the standard output of the net command.
            // This stream is read asynchronously using an event handler.
            netProcess.StartInfo.RedirectStandardOutput = true;
            netProcess.OutputDataReceived += new DataReceivedEventHandler(NetOutputDataHandler);
            netOutput = new StringBuilder();
            if (errorRedirect)
            {
                // Redirect the error output of the net command.
                netProcess.StartInfo.RedirectStandardError = true;
                netProcess.ErrorDataReceived += new DataReceivedEventHandler(NetErrorDataHandler);
            }
            else
            {
                // Do not redirect the error output.
                netProcess.StartInfo.RedirectStandardError = false;
            }
            Console.WriteLine("\nStarting process: net {0}",
                netProcess.StartInfo.Arguments);
            if (errorRedirect)
            {
                Console.WriteLine("Errors will be written to the file {0}",
                    netErrorFile);
            }
            // Start the process.
            netProcess.Start();
            // Start the asynchronous read of the standard output stream.
            netProcess.BeginOutputReadLine();
            if (errorRedirect)
            {
                // Start the asynchronous read of the standard
                // error stream.
                netProcess.BeginErrorReadLine();
            }
            // Let the net command run, collecting the output.
            netProcess.WaitForExit();
            if (streamError != null)
            {
                // Close the error file.
                streamError.Close();
            }
            else
            {
                // Set errorsWritten to false if the stream is not
                // open.   Either there are no errors, or the error
                // file could not be opened.
                errorsWritten = false;
            }
            if (netOutput.Length > 0)
            {
                // If the process wrote more than just
                // white space, write the output to the console.
                Console.WriteLine("\nPublic network shares from net view:\n{0}\n",
                    netOutput);
            }
            if (errorsWritten)
            {
                // Signal that the error file had something
                // written to it.
                String [] errorOutput = File.ReadAllLines(netErrorFile);
                if (errorOutput.Length > 0)
                {
                    Console.WriteLine("\nThe following error output was appended to {0}.",
                        netErrorFile);
                    foreach (String errLine in errorOutput)
                    {
                        Console.WriteLine("  {0}", errLine);
                    }
                }
                Console.WriteLine();
            }
            netProcess.Close();
        }
        private static void NetOutputDataHandler(object sendingProcess,
            DataReceivedEventArgs outLine)
        {
            // Collect the net view command output.
            if (!String.IsNullOrEmpty(outLine.Data))
            {
                // Add the text to the collected output.
                netOutput.Append(Environment.NewLine + "  " + outLine.Data);
            }
        }
        private static void NetErrorDataHandler(object sendingProcess,
            DataReceivedEventArgs errLine)
        {
            // Write the error text to the file if there is something
            // to write and an error file has been specified.
            if (!String.IsNullOrEmpty(errLine.Data))
            {
                if (!errorsWritten)
                {
                    if (streamError == null)
                    {
                        // Open the file.
                        try
                        {
                            streamError = new StreamWriter(netErrorFile, true);
                        }
                        catch (Exception e)
                        {
                            Console.WriteLine("Could not open error file!");
                            Console.WriteLine(e.Message.ToString());
                        }
                    }
                    if (streamError != null)
                    {
                        // Write a header to the file if this is the first
                        // call to the error output handler.
                        streamError.WriteLine();
                        streamError.WriteLine(DateTime.Now.ToString());
                        streamError.WriteLine("Net View error output:");
                    }
                    errorsWritten = true;
                }
                if (streamError != null)
                {
                    // Write redirected errors to the file.
                    streamError.WriteLine(errLine.Data);
                    streamError.Flush();
                }
            }
        }
    }
} 

string arg = string.Format(backupFmt, server, user, pwd, database, file);
  Process p = new Process();
  p.StartInfo.FileName = "cmd.exe";
  p.StartInfo.UseShellExecute = false;
  p.StartInfo.WorkingDirectory = location + @"bin";
  p.StartInfo.Arguments = arg;
  p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
  p.StartInfo.CreateNoWindow = true;
  p.StartInfo.RedirectStandardInput = true;
  p.StartInfo.RedirectStandardOutput = true; p.Start();
  StreamWriter sw = p.StandardInput;
  sw.WriteLine(arg);
  sw.WriteLine(Environment.NewLine);
  sw.Close();
#if DEBUG
  StreamReader sr = p.StandardOutput;
string str = sr.ReadToEnd();
if(!string.IsNullOrEmpty(str))
{
Console.WriteLine("restore file:" + file);
Console.WriteLine("message:" + str);
}
sr.Close();#endif
  p.WaitForExit();
  p.Close();

在C#中运行一个dos命令，并截取输出、输出流的问题，这个问题我以前在Java中实现过，由于在C#中没有遇到过类似的 情况，为了避免每次别人问都要一遍一遍演示的情况，特地做了一个简单的例子，实现在WinForm中ping一个网站，并且将ping的结果显示在一个文本框中。

private void btnExecute_Click(object sender, EventArgs e)
        {
            tbResult.Text = "";
            ProcessStartInfo start = new ProcessStartInfo("Ping.exe");//设置运行的命令行文件问ping.exe文件，这个文件系统会自己找到
            //如果是其它exe文件，则有可能需要指定详细路径，如运行winRar.exe
            start.Arguments = txtCommand.Text;//设置命令参数
            start.CreateNoWindow = true;//不显示dos命令行窗口
            start.RedirectStandardOutput = true;//
            start.RedirectStandardInput = true;//
            start.UseShellExecute = false;//是否指定操作系统外壳进程启动程序
            Process p=Process.Start(start);
            StreamReader reader = p.StandardOutput;//截取输出流
            string line = reader.ReadLine();//每次读取一行
            while (!reader.EndOfStream)
            {
                tbResult.AppendText(line+" ");
                line = reader.ReadLine();
            }
            p.WaitForExit();//等待程序执行完退出进程
            p.Close();//关闭进程
            reader.Close();//关闭流
        }