ASP.NET批量下载文件的方法

本文实例讲述了asp.net批量下载文件的方法。分享给大家供大家参考。具体方法如下：

一、实现步骤

在用户操作界面，由用户选择需要下载的文件，系统根据所选文件，在服务器上创建用于存储所选文件的临时文件夹，将所选文件拷贝至临时文件夹。然后调用 rar程序，对临时文件夹进行压缩，然后输出到客户端。最后删除临时文件夹。
 
二、代码实现
 
1、asp.net批量下载 核心代码

//遍历服务器指定文件夹下的所有文件
string path = "uploads/image/";
string serverpath = server.mappath(path);
//创建临时文件夹
string tempname = datetime.now.tostring("yyyymmddhhmmss");
string tempfolder = path.combine(serverpath, tempname);
directory.createdirectory(tempfolder);
directoryinfo folder = new directoryinfo(serverpath);
foreach (fileinfo file in folder.getfiles())
{
 string filename = file.name;
 file.copy(serverpath + "/" + filename, tempfolder + "/" + filename);
}
//zkhelper.jshelper.alert("图片拷贝成功!");
//产生rar文件，及文件输出
rarsave(tempfolder, tempname);
downloadrar(tempfolder + "\\\\" + tempname + ".rar");

 
2、rarsave(string tempfolder, string tempname) 方法

/// <summary>
/// 生成rar文件
/// </summary>
/// <param name="path">存放复制文件的目录</param>
/// <param name="rarpatch">rar文件存放目录</param>
/// <param name="rarname">rar文件名</param>
private void rarsave(string rarpatch, string rarname)
{
    string the_rar;
    registrykey the_reg;
    object the_obj;
    string the_info;
    processstartinfo the_startinfo;
    process the_process;
    try
    {
 the_reg = registry.classesroot.opensubkey(@"winrar");
 the_obj = the_reg.getvalue("");
 the_rar = the_obj.tostring();
 the_reg.close();
 the_rar = the_rar.substring(1, the_rar.length - 7);
 the_info = " a " + rarname + " -r";
 the_startinfo = new processstartinfo();
 the_startinfo.filename = "winrar";//the_rar;
 the_startinfo.arguments = the_info;
 the_startinfo.windowstyle = processwindowstyle.hidden;
 //打包文件存放目录
 the_startinfo.workingdirectory = rarpatch;
 the_process = new process();
 the_process.startinfo = the_startinfo;
 the_process.start();
 the_process.waitforexit();
 the_process.close();
    }
    catch (exception)
    {
 throw;
    }
}

 
3、downloadrar(string file)方法

/// <summary>
/// 下载生成的rar文件
/// </summary>
private void downloadrar(string file)
{
    fileinfo fileinfo = new fileinfo(file);
    response.clear();
    response.clearcontent();
    response.clearheaders();
    response.addheader("content-disposition", "attachment;filename=" + fileinfo.name);
    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();
    string temppath = file.substring(0, file.lastindexof("\\\\"));
    //删除临时目录下的所有文件
    deletefiles(temppath);
    //删除空目录
    directory.delete(temppath);
    response.end();
}

4、deletefiles(string temppath) 方法

/// <summary>
/// 删除临时目录下的所有文件
/// </summary>
/// <param name="temppath">临时目录路径</param>
private void deletefiles(string temppath)
{
    directoryinfo directory = new directoryinfo(temppath);
    try
    {
 foreach (fileinfo file in directory.getfiles())
 {
     if (file.attributes.tostring().indexof("readonly") != -1)
     {
  file.attributes = fileattributes.normal;
     }
     file.delete(file.fullname);
 }
    }
    catch (exception)
    {
 throw;
    }
}

希望本文所述对大家的asp.net#程序设计有所帮助。