asp.net 上传下载输出二进制流实现代码_实用技巧

复制代码 代码如下:

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Data.SqlClient;
using System.IO;
namespace Delegate
{
public partial class ReadStream : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
/// <summary>
/// 将上传的文件转换成二进制流保存在数据库
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Button1_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["sql"].ToString());
string strSql="insert into test(timage)values(@images)";//保存二进制流的方式需参数的形式
SqlCommand cmd = new SqlCommand(strSql, conn);
conn.Open();
string filepath = Server.MapPath("~/");
filepath += FileUpload1.FileName;
FileUpload1.SaveAs(filepath);
FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read);//读取文件
BinaryReader br = new BinaryReader(fs);
byte[] photo = br.ReadBytes((int)fs.Length);
br.Close();
fs.Close();
cmd.Parameters.Add("@images", SqlDbType.Binary, photo.Length);//设置参数
cmd.Parameters["@images"].Value = photo;//设置值
if (cmd.ExecuteNonQuery() == 1)
{
Response.Write("添加成功！");
}
conn.Close();
}
protected void Button2_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["sql"].ToString());
conn.Open();
string strSql = "select top 1 timage from test";
SqlCommand cmd = new SqlCommand(strSql, conn);
SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
if (dr.Read())
{
byte[] by = (byte[])dr[0];
Response.AddHeader("Content-Disposition", "attachment; filename=ceshi.txt");//设置读取的文件头
Response.AddHeader("Content-Length", by.Length.ToString());
Response.ContentType = "text/plain";//设置输出类型 这里可以保存在数据库中 动态实现类型
Response.OutputStream.Write(by, 0, by.Length); //输出
Response.Flush();
}
conn.Close();
}
}
}