ASP.NET下文件批量下载应用
1.场景描述
在B/S环境下，客户提出批量导出员工照片功能。具体为：选中一个部门或者单位，系统能够批量下载所选单元的照片，下载到用户客户端。
2.解决思路
由于系统中员工的照片存储在服务器硬盘上，因此，应该有两种方式供用户选择：其一，写一个C/S客户端，利用客户端功能，实现客户端批量下载操作。其二，在现有ASP.NET环境下，将所需照片文件合并成一个文件下载到用户客户端。比较而言，两种思路的难度都不大，但是考虑到系统的统一性，最终决定采用方案二，将文件打包后下载。
3.实现步骤
在用户操作界面，由用户选择员工，系统根据所选人员，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。
4.部分关键代码
创建临时文件夹
string Folder = DateTime.Now.ToString("HHMMss");
string tempFolder = Path.Combine(ImagesPath, Folder);
Directory.CreateDirectory(tempFolder);
var empList = rs.ToList();
拷贝照片文件
foreach (var x in empList)
{
File.Copy(ImagesPath @"\" x.ID ".jpg", tempFolder @"\" x.DeptName "-" x.Name "-" x.ID ".jpg");
}
产生RAR文件，及文件输出
RARsave(tempFolder, tempFolder, Folder);
ResponseFile(tempFolder @"\" Folder ".rar");
public void RARsave(string patch, 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);
Directory.CreateDirectory(patch);
//命令参数
//the_Info = " a " rarName " " @"C:Test?70821.txt"; //文件压缩
the_Info = " a " rarName " " patch " -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 ex)
{
throw ex;
}
}
protected void ResponseFile(string fileName)
{
FileInfo fileInfo = new FileInfo(fileName);
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();
string tempPath = fileName.Substring(0, fileName.LastIndexOf("\\"));
DelDir(tempPath);
Directory.Delete(tempPath);
Response.End();
}
关键词标签：ASP.NET
