文件上传这个我看来有两种上传方法：一、上传到服务器上把文件地址存入数据库中 二、直接把文件以字节数存储

第一种方式比较常见：可以使用文件流的形式把文件写入到服务器端。

今天主要说明第二种方法：

因为我做的是web项目，所以上传工具就用到了FileUpload控件如何实现的呢，不废话上代码

default.aspx

　　这里把文件上传单独放到一个页面，我们利用iframe来加载【附件 AttachFileUpload】的页面

AttachFileUpload.aspx

　　AttachFileUpload.aspx.cs

protected void btnFileUpload_Click(object sender, EventArgs e)        {            string l_strFullName = fuFileUpload.PostedFile.FileName;            string l_strFileName = l_strFullName.Substring(l_strFullName.LastIndexOf("\\") + 1);            try            {                byte[] l_bytFile = fuFileUpload.f.FileBytes;                Session["FileName"] = l_strFileName;                Session["FileData"] = l_bytFile;                ClientScript.RegisterStartupScript(this.GetType(), "ShowMsgAndRefresh", "parent.ShowMsgAndRefresh()", true);            }            catch            {                return;            }        }

Default.aspx.cs

/// 
        /// 附件下载        /// 
        ///         ///         protected void lbtnAttachFiles_Click(object sender, EventArgs e)        {            string l_strFileName = Session["FileName"].ToString();            byte[] l_bytFileData = Session["FileData"] as byte[];            HttpContext.Current.Response.Clear();            l_strFileName = System.Web.HttpUtility.UrlEncode(l_strFileName);            HttpContext.Current.Response.ContentType = "application/octet-stream";            HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + l_strFileName);            if (l_bytFileData.Length == 0)            {                l_bytFileData = System.Text.Encoding.Unicode.GetBytes(" ");            }            HttpContext.Current.Response.BinaryWrite(l_bytFileData);            HttpContext.Current.Response.Flush();            HttpContext.Current.Response.End();        }        /// 
        /// 附件添加删除处理        /// 
        ///         ///         protected void btnRecordDelete_Click(object sender, EventArgs e)        {            if (btnRecordDelete.Text.Trim() == "附件")            {                ClientScript.RegisterStartupScript(this.Page.GetType(), "OpenFileDialogAndInsert", "");            }            else if (btnRecordDelete.Text.Trim() == "删除")            {                Session["FileName"] = string.Empty;                Session["FileData"] = null;                lbtnAttachFiles.Text = Session["FileName"].ToString();                //lbtnAttachFiles.ToolTip = Session["FileName"].ToString();                btnRecordDelete.Text = "附件";            }        }        /// 
        /// 附件添加完成后的处理        /// 
        ///         ///         protected void btnHidView_Click(object sender, EventArgs e)        {            lbtnAttachFiles.Text = Session["FileName"].ToString();            //lbtnAttachFiles.ToolTip = Session["FileName"].ToString();            if (!string.IsNullOrEmpty(lbtnAttachFiles.Text.Trim()))            {                btnRecordDelete.Text = "删除";            }        }