asp.net 上传下载输出二进制流实现代码_.net

asp.net 上传下载输出二进制流实现代码

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(); 
} 
} 
}