Response.WriteFile实现文件下载

/// <summary>
    /// Response.AddHeader实现下载
    /// </summary>
    /// <param name="filePath">完整的文件路径</param>
    /// <param name="fileName">文件名</param>
    private void DownFile(string filePath, string fileName)
    {
        FileInfo fileInfo = new FileInfo(filePath);
        Response.Clear();
        Response.ClearContent();
        Response.ClearHeaders();
        Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
        Response.AddHeader("Content-Length", fileInfo.Length.ToString());
        Response.AddHeader("Content-Transfer-Encoding", "binary");
        Response.ContentType = "application/octet-stream";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
        Response.WriteFile(fileInfo.FullName);
        Response.Flush();
        Response.End();
    }