.net 根据文件地址下载文件

前端代码:
<a href="/Test/getFilePath">
后台代码：
public class Test{
public string getFilePath(){
return "http://192.168.0.1//upload//文件1.doc";
}}

public ActionResult getFilePath(string a_id)
        {
            string path = _DocClient.IGetDocAnnexSevicReturnByReceive(a_id);//获取文件地址
            System.Net.HttpWebRequest httpWebRequest = null;
            string filename = path.Substring(path.LastIndexOf("/") + 1, path.Length - path.LastIndexOf("/") - 1);//获取文件名
            httpWebRequest = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(path);
            System.Net.HttpWebResponse httpWebResponse = (System.Net.HttpWebResponse)httpWebRequest.GetResponse();
            System.IO.Stream sr = httpWebResponse.GetResponseStream();
            return File(sr, "text/html", filename);
           
        }