C# javascript文件下载时改变文件名

 在项目中有时会出现下载文件的问题，服务器上保存的文件也许是已GUID命名的文件，但在下载时，也许需要指定一个文件名。我项目中就用到了，到这里做下笔记：
首先在页面上放一个<iframe>标签：

<iframe id="ifrLoad" frameborder="0" name="weidu" scrolling="no" width="100%" height="100%">        </iframe>

再在js中写如下方法：

function FileDownLoad(filePath, fileName) {    document.getElementById("ifrLoad").setAttribute("src", encodeURI("FileDownLoad.aspx?filePath=" + filePath + "&fileName=" + fileName));}

注意文件名如果是中文要记得用：js 的encodeURI（）方法进行编码传输

再到FileDownLoad.aspx页面后台代码进行转码操作，直接贴代码：

public partial class FileDownLoad : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            string filePath = Request.Params["filePath"];            string fileName = HttpUtility.UrlDecode(Request.Params["fileName"]);            if (filePath != null)            {                BigFileDownload(fileName, filePath);            }        }        /// <summary>        /// 文件下载        /// </summary>        /// <param name="FileName">文件名</param>        /// <param name="FilePath">路径</param>        public void BigFileDownload(string FileName, string FilePath)        {            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 = System.Web.HttpContext.Current.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=" + System.Web.HttpUtility.UrlEncode(FileName));//System.Text.UTF8Encoding.UTF8.GetBytes(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;                    }                }            }            catch (Exception ex)            {                // Trap the error, if any.                string message = ex.Message;                this.Page.ClientScript.RegisterStartupScript(GetType(), "Message", "<script>alert('Error : " + message + "');</script>");            }            finally            {                if (iStream != null)                {                    //Close the file.                    iStream.Close();                }            }        } }

这样当点击文件列表进行下载时：就会将以你传入的文件名作为下载的文件名

<td style="width: 60%; height: 25px">    <a href="javascript:void(0)"  onclick="FileDownLoad('../File/aseaglnsdf234dkfauoiomsadfk.doc','新设立外商投资企业区域分布情况报告（国家工商行政管理总局）.doc')">新设立外商投资企业区域分布情况报告（国家工商行政管理总局）</a></td>

 

效果图如下：

 

实际上服务器上存的文件是：guid命名的文件
效果图如下：

 

以上内容摘自http://www.cnblogs.com/joey0210/archive/2011/09/02/2163659.html

在实际运用过程中，可以通过新的aspx页面来达到下载或者生成一个新的文件的目的。