VS2010 C#环境变量自动配置及运行CMD命令不显示结果

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.IO;

namespace PathWindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            button1_Click(null,null);
           
        }

        public string SetPath(string pathName,string pathValue,string delete)  //删除delete 要大写，再加到后面。
        {
           
            string pathlist;
            pathlist = Environment.GetEnvironmentVariable(pathName, EnvironmentVariableTarget.Machine);
            if (pathlist == null)
            {
                Environment.SetEnvironmentVariable(pathName, pathValue, EnvironmentVariableTarget.Machine);
            }
            else
            {
                string temp="";
                string[] list = pathlist.Split(";");
                foreach (string item in list)
                {
                    if (!item.ToUpper().Contains(delete) && item != pathValue && item!="")
                        temp += item+";";
                }
                Environment.SetEnvironmentVariable(pathName, temp +  pathValue + ";", EnvironmentVariableTarget.Machine);
          
            }
            return pathName + "=" + Environment.GetEnvironmentVariable(pathName, EnvironmentVariableTarget.Machine);
        }
        public string SetPath(string pathName, string pathValue)//删除原来的并新增
        {
             Environment.SetEnvironmentVariable(pathName, pathValue, EnvironmentVariableTarget.Machine);         
            return pathName + "=" + Environment.GetEnvironmentVariable(pathName, EnvironmentVariableTarget.Machine);
        }
     private void ExcuteDosCommand(string cmd)  
        {  
            try  
            {  
               Process p = new Process();  
               p.StartInfo.FileName = "cmd";  
               p.StartInfo.UseShellExecute = false;  
               p.StartInfo.RedirectStandardInput = true;  
               p.StartInfo.RedirectStandardOutput = true;  
               p.StartInfo.RedirectStandardError = true;  
               p.StartInfo.CreateNoWindow = true;            
               p.OutputDataReceived += new DataReceivedEventHandler(sortProcess_OutputDataReceived);  
               p.Start();  
               StreamWriter cmdWriter = p.StandardInput;  
               p.BeginOutputReadLine();  
               if (!String.IsNullOrEmpty(cmd))  
               {  
                   cmdWriter.WriteLine(cmd);
                  
               }
              
               cmdWriter.Close();  
               p.WaitForExit();  
               p.Close();    
            }  
            catch(Exception ex)  
            {  
               MessageBox.Show("执行命令失败，请检查输入的命令是否正确！"+ex.ToString());  
            }  
        }  
   
        private void sortProcess_OutputDataReceived(object sender,DataReceivedEventArgs e)  
        {  
            if(!String.IsNullOrEmpty(e.Data))  
            {  
               this.BeginInvoke(new Action(() => { 
                   
                   textBox1.Text += e.Data + System.Environment.NewLine;
               }));                    
            }  
        }  

        private void button1_Click(object sender, EventArgs e)
        {
            button1.Enabled = false;
            textBox1.Text = "";
            textBox1.Text += "开始设置JAVA变量" + System.Environment.NewLine;
            //  textBox1.Text += SetPath("JAVA_HOME", @"C:Program FilesJavajdk1.8.0_60") + System.Environment.NewLine; 
            textBox1.Text += SetPath("JAVA_HOME", @"C:Program FilesJavajdk1.8.0_05") + System.Environment.NewLine;  //32位
            textBox1.Text += SetPath("CLASSPATH", @".;%JAVA_HOME%lib;%JAVA_HOME%lib	ools.jar") + System.Environment.NewLine;
            textBox1.Text += SetPath("Path", @"%JAVA_HOME%in;%JAVA_HOME%jrein", "JAVA") + System.Environment.NewLine;
            textBox1.Text += "设置完毕" + System.Environment.NewLine;
    
            //      ExcuteDosCommand("java -version");  //为什么不显示结果？？
            button1.Enabled = true;
            
        }
    }
}