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asp.net中如何实现多个文件同时下载
来源：长沙北大青鸟 发布日期：2017-04-06如何实现asp.net多个文件同时下载?先要读取文件夹下的文件，可能同时存在多个文件;然后选中文件，然后点击下载，同时可以选择多个文件。通过生产压缩包的形式进行下载，然后再清除压缩包，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()) |
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 > 0) { 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 = 0; 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"), 9);//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 = 0; 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, 0, 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, 0, buffer.Length); m++; } } catch { throw; } finally { s.Finish(); s.Close(); } } |
三、系统中需要引用的dll 需要下载。
引用文件dll：ICSharpCode.SharpZipLib.dll
1. 合成下载文件夹
| Protected Sub btn_down_click(ByVal sender As Object, ByVal e As EventArgs) Handles btn_Down.Click If txtBz.Text.Trim = "" Then Page.ClientScript.RegisterClientScriptBlock(Me.[GetType](), "", "alert('请填写下载备注！');", True) Exit Sub End If Dim i As Integer Dim selcount As Integer = 0 Dim fileList As List(Of String) = New List(Of String)() If rptList.Items.Count > 0 Then For i = 0 To rptList.Items.Count - 1 Dim chk As CheckBox = rptList.Items(i).FindControl("cbkItem") If chk IsNot Nothing AndAlso chk.Checked Then selcount += 1 Dim filePath As HiddenField = rptList.Items(i).FindControl("hfUrl") Dim fileName As HiddenField = rptList.Items(i).FindControl("hfFileName") If filePath IsNot Nothing Then Dim root As String = Request.PhysicalApplicationPath Dim tmpUrl = root + filePath.Value fileList.Add(tmpUrl + "|" + fileName.Value) '最后结果为：路径|名称 End If End If Next End If Dim time As String = DateTime.Now.Ticks.ToString() Dim baseFolder As String = HttpContext.Current.Request.MapPath("~/UploadFile/TempWorkFlow/") If Not Directory.Exists(baseFolder) Then Directory.CreateDirectory(baseFolder) End If If selcount = 0 Then Page.ClientScript.RegisterClientScriptBlock(Me.[GetType](), "", "alert('请选择要下载的文件！');", True) Exit Sub Else ZipFileMain(fileList.ToArray(), baseFolder & time & ".zip", 9) '压缩文件 DownloadFile(Server.UrlEncode("附件.zip"), baseFolder & time & ".zip") 'Response.Redirect("Download.aspx?FileName=" & Server.UrlEncode("附件.zip") & "&FilePath=" & baseFolder & time & ".zip") End If End Sub |
2. 压缩下载函数
| ''' <summary> ''' 压缩文件 ''' </summary> ''' <param name="fileName">要压缩的所有文件（完全路径)</param> ''' <param name="name">压缩后文件路径</param> ''' <param name="Level">压缩级别</param> Public Shared Sub ZipFileMain(filenames As String(), name As String, Level As Integer) Dim s As New ZipOutputStream(File.Create(name)) Dim crc As New Crc32() '压缩级别 s.SetLevel(Level) ' 0 - store only to 9 - means best compression Try For Each file__1 As String In filenames '打开压缩文件 Dim fs As FileStream = File.OpenRead(file__1.Split("|"c)(0)) '文件地址 Dim buffer As Byte() = New Byte(fs.Length - 1) {} fs.Read(buffer, 0, buffer.Length) '建立压缩实体 Dim entry As New ZipEntry(file__1.Split("|"c)(1)) '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, 0, buffer.Length) Next Catch 'Throw Finally s.Finish() s.Close() End Try End Sub |
3. 压缩下载函数
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<table class="table table-hover table-bordered table-striped"> |
四、运行效果如图：
