asp.net 文件下载功能函数代码整理

代码如下:

public void FileDownLoadDel(string fullFilename) 
{ 
System.IO.Stream iStream = null; 
// Buffer to read 10K bytes in chunk: 
byte[] buffer = new Byte[10000]; 
// Length of the file: 
int length; 
// Total bytes to read: 
long dataToRead; 
// Identify the file to download including its path. 
string filepath = fullFilename; 
filepath = Server.MapPath(filepath); 
// Identify the file name. 
string filename = System.IO.Path.GetFileName(filepath); 

try 
{ 
// Open the file. 
iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open, 
System.IO.FileAccess.Read, System.IO.FileShare.Read); 

// Total bytes to read: 
dataToRead = iStream.Length; 
Response.ContentType = "application/octet-stream"; 
Response.AddHeader("Content-Disposition", "attachment; filename=" + filename); 
// Read the bytes. 
while (dataToRead > 0) 
{ 
// Verify that the client is connected. 
if (Response.IsClientConnected) 
{ 
// Read the data in buffer. 
length = iStream.Read(buffer, 0, 10000); 
// Write the data to the current output stream. 
Response.OutputStream.Write(buffer, 0, length); 
// Flush the data to the HTML output. 
Response.Flush(); 
buffer = new Byte[10000]; 
dataToRead = dataToRead - length; 
} 
else 
{ 
//prevent infinite loop if user disconnects 
dataToRead = -1; 
Response.Clear(); 
} 
} 
Response.End(); //没有这句会将该页面刷新后的内容追加写入文件中。 
} 
catch (Exception ex) 
{ 
// Trap the error, if any. 
//Response.Write("Error : " + ex.Message); 
//base.WriteLog("资料", "下载资料:" + ex.Message + "!", LogType.Error, this.GetType().ToString()); 
} 
finally 
{ 
if (iStream != null) 
{ 
//Close the file. 
iStream.Close(); 
} 
File.Delete(fullFilename); 
} 
}