c#中重定向windows控制台程序的输出信息

这个问题来自社区提问，代码保留一份用来以后回答

using System;
using System.ComponentModel;
using System.Windows.Forms;
namespace WindowsApplication4
...{
/**//// 

/// gui 类
/// 

public partial class Form1 : Form
...{
public Form1()
...{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
...{
//用子线程工作
new System.Threading.Thread(new System.Threading.ThreadStart(StartDownload))
.Start();
}
//开始下载
public void StartDownload()
...{
Downloader downloader = new Downloader();
downloader.onDownLoadProgress += new Downloader.dDownloadProgress(downloader_
onDownLoadProgress);
downloader.Start();
}
//同步更新ui
void downloader_onDownLoadProgress(long total, long current)
...{
if (this.InvokeRequired)
...{
this.Invoke(new Downloader.dDownloadProgress(downloader_onDownLoadProgress),
new object[] ...{ total, current });
}
else
...{
this.progressBar1.Maximum = (int)total;
this.progressBar1.Value = (int)current;
}
}
}
/**//// 

/// 下载类
/// 

public class Downloader
...{
//委托
public delegate void dDownloadProgress(long total,long current);
//事件
public event dDownloadProgress onDownLoadProgress;
//开始模拟工作
public void Start()
...{
for (int i = 0; i < 100; i++)
...{
if (onDownLoadProgress != null)
onDownLoadProgress(100, i);
System.Threading.Thread.Sleep(100);
}
}
}
}