asp.net lists all documents in a folder including files in subdirectories

 
protected void Page_Load(object sender, EventArgs e) 
{ 
// Specify the destination folder  
string directory = @"C:\Windows\Microsoft.NET\Framework\v3.5"; 

IterationFile(directory); 
} 

private void IterationFile(string path) 
{ 
DirectoryInfo di = new DirectoryInfo(path); 

// Output the current directory.  
Response.Write(di.ToString() + "<br />"); 
// Gets all the files in the current directory  
FileInfo[] fiArray = di.GetFiles(); 

// Each cycle 1 A file  
for (int i = 0; i < fiArray.Length; i++) 
{ 
Response.Write(fiArray[i].ToString() + "<br/>"); 
} 

// At the end of each directory, write 1 A blank line.  
Response.Write("----------------------------------------------------------------------------<br/>"); 
// Gets all subdirectories in the current directory  
DirectoryInfo[] diArray = di.GetDirectories(); 

// Each cycle 1 A directory  
for (int j = 0; j < diArray.Length; j++) 
{ 
IterationFile(diArray[j].FullName); 
} 
}