1、首先读取文件夹下的文件，可能同时存在多个文件
2、选中文件，然后点击下载，同时可以选择多个文件。
思路：通过生产压缩包的形式进行下载，然后再清楚压缩包，这样用户可以一次性全部下载下来。
一、获取目录下的所有文件，然后绑定到checkboxlist中 ，代码如下：
ckl_ck.Items.Clear();
DirectoryInfo TheFolder = new DirectoryInfo(Server.MapPath("Resource/Help"));
//遍历文件夹下的文件
foreach (FileInfo NextFile in TheFolder.GetFiles())
this.ckl_ck.Items.Add(NextFile.Name);
二、选中文件后，点击下载按钮。代码：
protected void Btn_down_Click(object sender, EventArgs e)
{
if (ckl_ck.Items.Count > )
{
List<string> listFJ = new List<string>();//保存附件路径
List<string> listFJName = new List<string>();//保存附件名字
for (int i = ; i < ckl_ck.Items.Count; i++)
{
if (ckl_ck.Items[i].Selected)
{
listFJ.Add(Server.MapPath("Resource/Help/") + ckl_ck.Items[i].Text);
listFJName.Add(ckl_ck.Items[i].Text);
} }
string time = DateTime.Now.Ticks.ToString();
ZipFileMain(listFJ.ToArray(), listFJName.ToArray(), Server.MapPath("Resource/Help/" + time + ".zip"), );//压缩文件
DownloadFile(Server.UrlEncode("附件.zip"), Server.MapPath("Resource/Help/" + time + ".zip"));//下载文件
}
}
private void DownloadFile(string fileName, string filePath)
{
FileInfo fileInfo = new FileInfo(filePath);
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();
File.Delete(filePath);//删除已下载文件
Response.End();
} /// <summary>
/// 压缩文件
/// </summary>
/// <param name="fileName">要压缩的所有文件（完全路径)</param>
/// <param name="fileName">文件名称</param>
/// <param name="name">压缩后文件路径</param>
/// <param name="Level">压缩级别</param>
public void ZipFileMain(string[] filenames, string[] fileName, string name, int Level)
{
ZipOutputStream s = new ZipOutputStream(File.Create(name));
Crc32 crc = new Crc32();
//压缩级别
s.SetLevel(Level); // 0 - store only to 9 - means best compression
try
{
int m = ;
foreach (string file in filenames)
{
//打开压缩文件
FileStream fs = File.OpenRead(file);//文件地址
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, , buffer.Length);
//建立压缩实体
ZipEntry entry = new ZipEntry(fileName[m].ToString());//原文件名
//时间
entry.DateTime = DateTime.Now;
//空间大小
entry.Size = fs.Length;
fs.Close();
crc.Reset();
crc.Update(buffer);
entry.Crc = crc.Value;
s.PutNextEntry(entry);
s.Write(buffer, , buffer.Length);
m++;
}
}
catch
{
throw;
}
finally
{
s.Finish();
s.Close();
}
}
三、系统中需要引用的dll http://download.csdn.net/detail/njxiaogui/8251031 需要下载。
四、运行效果如图：