asp.netmvc如何实现文件下载.doc

文档介绍：
public static bool DownloadFile(HttpContext httpContext, string filePath, long speed)
{
bool ret = true;
try
{
#region--验证：HttpMethod，请求的文件是否存在
switch (())
{ //目前只支持GET和HEAD方法
case "GET":
case "HEAD":
break;
default:
= 501;
return false;
}
if (!(filePath))
{
= 404;
return false;
}
#endregion

#region 定义局部变量
long startBytes = 0;
int packSize = 1024 * 10; //分块读取，每块10K bytes
string fileName = (filePath);
FileStream myFile = new FileStream(filePath, , , );
BinaryReader br = new BinaryReader(myFile);
long fileLength = ;

int sleep = (int)( * packSize / speed);//毫秒数：读取下一数据块的时间间隔
string lastUpdateTiemStr = (filePath).ToString("r");
string eTag = (fileName, ) + lastUpdateTiemStr;//便于恢复下载时提取请求头;
#endregion