Download nhiều file cho một lần Click trong Asp.net

By Unknown - Monday, August 3, 2015 - No Comments

(How to download multi files in ASP.Net) – Khi có 1 danh sách các file cần Download, nếu phải kích vào từng File để Download thì mất rất nhiều thời gian cho người dùng. Vậy có cách nào để có thể chọn các file cần và Click một lần là toàn bộ các file này sẽ được Download. Bài viết dưới đây sẽ hướng dẫn các bạn thực hiện điều đó.

Xem những Video hay dành cho thiếu nhi - Nghe trên Youtube

- B1: Tạo Project trong Microsoft Visual Studio 2010

- B2: Download thư viện SharpZipLib.dll và References vào Project

- B3: Mở file Default.aspx dưới dạng HTML và nhập mã HTML
C# Code

<%@ Page Title="Download Multiple Files in ASP.Net using C# and VB.Net" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="DownloadMultipleFiles._Default" %>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

<tr>

<td>

<asp:label id="lblHeader" runat="server" Text="Download Multiple Files"></asp:label>

</div>

<tr>

<td>

<asp:LinkButton id="cmdDownload" runat="server" CssClass="btn btn-small" OnClick="cmdDownload_Click" Causesvalidation="false">

</asp:LinkButton>

</td>

</tr>

<tr>

<td>

<asp:GridView ID="grvObject" runat="server" AllowPaging="true" PageSize="8"

CssClass="GridStyle" BorderColor="#cbcbcb" BorderStyle="solid"

BorderWidth="1" AutoGenerateColumns="false" width="100%" onrowdatabound="grvObject_RowDataBound">

<asp:TemplateField>

<asp:CheckBox ID="chkAll" runat="server" />

</HeaderTemplate>

<asp:CheckBox ID="chkSelect" runat="server" />

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="Name" SortExpression="Name">

<asp:Label ID="lblFileName" Visible="false" runat="server"></asp:Label>

<asp:Literal runat="server" ID="ltlFileItem"></asp:Literal>

</ItemTemplate>

</asp:TemplateField>

<asp:BoundField DataField="CreationTime" HeaderText="Creation Time" SortExpression="CreationTime" />

<asp:BoundField DataField="LastWriteTime" HeaderText="Date Modified" SortExpression="LastWriteTime" />

<asp:TemplateField HeaderText="Size" SortExpression="Size" ItemStyle-HorizontalAlign="Right">

<%# DisplaySize((long?) Eval("Size")) %>

</ItemTemplate>

</asp:TemplateField>

</Columns>

</asp:GridView>

</td>

</tr>

</table>

</div>

</td>

</tr>

</table>

</asp:Content>

VB.NET Code

<%@ Page Title="Download Multiple Files in ASP.Net using C# and VB.Net" Language="vb" MasterPageFile="~/Site.Master" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="DownloadMultipleFiles._Default" %>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

<tr>

<td>

<asp:label id="lblHeader" runat="server" Text="Download Multiple Files"></asp:label>

</div>

<tr>

<td>

<asp:LinkButton id="cmdDownload" runat="server" CssClass="btn btn-small" Causesvalidation="false">

</asp:LinkButton>

</td>

</tr>

<tr>

<td>

<asp:GridView ID="grvObject" runat="server" AllowPaging="true" PageSize="8"

CssClass="GridStyle" BorderColor="#cbcbcb" BorderStyle="solid"

BorderWidth="1" AutoGenerateColumns="false" width="100%">

<asp:TemplateField>

<asp:CheckBox ID="chkAll" runat="server" />

</HeaderTemplate>

<asp:CheckBox ID="chkSelect" runat="server" />

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="Name" SortExpression="Name">

<asp:Label ID="lblFileName" Visible="false" runat="server"></asp:Label>

<asp:Literal runat="server" ID="ltlFileItem"></asp:Literal>

</ItemTemplate>

</asp:TemplateField>

<asp:BoundField DataField="CreationTime" HeaderText="Creation Time" SortExpression="CreationTime" />

<asp:BoundField DataField="LastWriteTime" HeaderText="Date Modified" SortExpression="LastWriteTime" />

<asp:TemplateField HeaderText="Size" SortExpression="Size" ItemStyle-HorizontalAlign="Right">

<%# DisplaySize(CType(Eval("Size"), Nullable(Of Long))) %>

</ItemTemplate>

</asp:TemplateField>

</Columns>

</asp:GridView>

</td>

</tr>

</table>

</div>

</td>

</tr>

</table>

</asp:Content>

- B4: Trong Visual Studio tạo 1 Class có tên: FileSystemItem và nhập đoạn Code phía dưới cho Class này.
C# Code

using Microsoft.VisualBasic;

using System;

using System.Collections;

using System.Collections.Generic;

using System.Data;

using System.Diagnostics;

using System.IO;

public class FileSystemItem

{

public FileSystemItem(FileInfo file)

{

this.Name = file.Name;

this.FullName = file.FullName;

this.Size = file.Length;

this.CreationTime = file.CreationTime;

this.LastAccessTime = file.LastAccessTime;

this.LastWriteTime = file.LastWriteTime;

}

public string Name { get; set; }

public string FullName { get; set; }

public Nullable<long> Size { get; set; }

public DateTime CreationTime { get; set; }

public DateTime LastAccessTime { get; set; }

public DateTime LastWriteTime { get; set; }

}

VB.NET Code

Imports System.IO

Public Class FileSystemItem

Public Sub New(ByVal file As FileInfo)

Me.Name = file.Name

Me.FullName = file.FullName

Me.Size = file.Length

Me.CreationTime = file.CreationTime

Me.LastAccessTime = file.LastAccessTime

Me.LastWriteTime = file.LastWriteTime

End Sub

Public Property Name As String

Public Property FullName As String

Public Property Size As Nullable(Of Long)

Public Property CreationTime As DateTime

Public Property LastAccessTime As DateTime

Public Property LastWriteTime As DateTime

End Class

- B5: Viết Code cho file Default.aspx
C# Code

//Visit http://www.laptrinhdotnet.com for more ASP.NET Tutorials

using Microsoft.VisualBasic;

using System;

using System.Collections;

using System.Collections.Generic;

using System.Data;

using System.IO;

using System.Diagnostics;

using System.Web.UI;

using System.Web.UI.WebControls;

using ICSharpCode.SharpZipLib.Zip;

namespace DownloadMultipleFiles

{

public partial class _Default : System.Web.UI.Page

{

#region "Private Members"

string FilePath = "";

#endregion

#region "Private Methods"

private void SetFilePath()

{

FilePath = MapPath("~/Upload/");

if (!Directory.Exists(FilePath))

{

Directory.CreateDirectory(FilePath);

}

protected string DisplaySize(long? size)

{

if (size == null)

return string.Empty;

else

{

if (size < 1024)

return string.Format("{0:N0} bytes", size.Value);

else

return String.Format("{0:N0} KB", size.Value / 1024);

}

private string GetFullyQualifiedFolderPath(string folderPath)

{

if (folderPath.StartsWith("~"))

{

return Server.MapPath(folderPath);

}

else

{

return folderPath;

}

#endregion

#region "GridView Methods"

protected void grvObject_RowDataBound(object sender, System.Web.UI.WebControls.GridViewRowEventArgs e)

{

if (e.Row.RowType == DataControlRowType.DataRow)

{

FileSystemItem item = (FileSystemItem)e.Row.DataItem;

Label lblFileName = (Label)e.Row.FindControl("lblFileName");

if (lblFileName != null)

{

lblFileName.Text = item.FullName;

}

Literal ltlFileItem = (Literal)e.Row.FindControl("ltlFileItem");

if (lblFileName != null)

{

ltlFileItem.Text = item.Name;

}

#endregion

#region "Bind Data"

private void BindData()

{

DirectoryInfo currentDirInfo = new DirectoryInfo(GetFullyQualifiedFolderPath(FilePath));

dynamic folders = currentDirInfo.GetDirectories();

dynamic files = currentDirInfo.GetFiles();

var fsItems = new List<FileSystemItem>(folders.Length + files.Length);

foreach (var file in files)

fsItems.Add(new FileSystemItem(file));

grvObject.DataSource = fsItems;

grvObject.DataBind();

}

#endregion

#region "Event Handles"

protected void Page_Load(object sender, System.EventArgs e)

{

try

{

if (!IsPostBack)

{

SetFilePath();

BindData();

}

catch

{

}

private void DownloadFile(string filepath)

{

if (!string.IsNullOrEmpty(filepath))

{

System.IO.FileInfo file = new System.IO.FileInfo(filepath);

if (file.Exists)

{

Response.Clear();

Response.ClearContent();

Response.ClearHeaders();

Response.BufferOutput = false;

Response.ContentType = "application/zip";

Response.AddHeader("content-disposition", "attachment; filename=" + file.Name);

Response.WriteFile(file.FullName);

file.Delete();

Response.End();

}

else

{

Response.Write("This file does not exist.");

}

else

{

Response.Write("Please provide a file to download.");

}

protected void cmdDownload_Click(object sender, System.EventArgs e)

{

try

{

SetFilePath();

int intCount = grvObject.Rows.Count;

CheckBox chkSelect = default(CheckBox);

Label lblLabel = default(Label);

int i = 0;

if (intCount > 0)

{

string sZipFileName = string.Format("Zip_{0}.zip", DateTime.Now.ToString("yyyy-MM-dd-HHmmss"));

ZipOutputStream s = new ZipOutputStream(File.Create(FilePath + "\\" + sZipFileName));

s.SetLevel(9);

byte[] buffer = null;

buffer = new byte[4097];

for (i = 0; i <= intCount - 1; i++)

{

chkSelect = (CheckBox)grvObject.Rows[i].FindControl("chkSelect");

lblLabel = (Label)grvObject.Rows[i].FindControl("lblFileName");

if ((chkSelect != null) & (lblLabel != null))

{

string FileName = "";

if (lblLabel != null)

{

FileName = lblLabel.Text;

}

if (!string.IsNullOrEmpty(FileName) && chkSelect.Checked)

{

ZipEntry entry = new ZipEntry(Path.GetFileName(FileName));

entry.DateTime = DateTime.Now;

s.PutNextEntry(entry);

FileStream fs = File.OpenRead(FileName);

int sourceBytes = 1;

while (!((sourceBytes <= 0)))

{

sourceBytes = fs.Read(buffer, 0, buffer.Length);

s.Write(buffer, 0, sourceBytes);

}

fs.Close();

}

s.Finish();

s.Close();

DownloadFile(FilePath + "\\" + sZipFileName);

}

catch

{

return;

}

finally

{

}

#endregion

}

VB.Net Code

'Visit http://www.laptrinhdotnet.com for more ASP.NET Tutorials

Imports System.IO

Imports ICSharpCode.SharpZipLib.Zip

Imports ICSharpCode.SharpZipLib.Checksums

Imports ICSharpCode.SharpZipLib.GZip

Namespace DownloadMultipleFiles

Public Class _Default

Inherits System.Web.UI.Page

#Region "Private Members"

Private FilePath As String = ""

#End Region

#Region "Private Methods"

Private Sub SetFilePath()

FilePath = MapPath("~/Upload")

If Not Directory.Exists(FilePath) Then

Directory.CreateDirectory(FilePath)

End If

End Sub

Protected Function DisplaySize(ByVal size As Nullable(Of Long)) As String

If size Is Nothing Then

Return String.Empty

Else

If size < 1024 Then

Return String.Format("{0:N0} bytes", size.Value)

Else

Return String.Format("{0:N0} KB", size.Value / 1024)

End If

End Function

Private Function GetFullyQualifiedFolderPath(ByVal folderPath As String) As String

If folderPath.StartsWith("~") Then

Return Server.MapPath(folderPath)

Else

Return folderPath

End If

End Function

#End Region

#Region "GridView Methods"

Protected Sub grvObject_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles grvObject.RowDataBound

If e.Row.RowType = DataControlRowType.DataRow Then

Dim item As FileSystemItem = CType(e.Row.DataItem, FileSystemItem)

Dim lblFileName As Label = CType(e.Row.FindControl("lblFileName"), Label)

If Not lblFileName Is Nothing Then

lblFileName.Text = item.FullName

End If

Dim ltlFileItem As Literal = CType(e.Row.FindControl("ltlFileItem"), Literal)

If Not lblFileName Is Nothing Then

ltlFileItem.Text = item.Name

End If

End Sub

#End Region

#Region "Bind Data"

Private Sub BindData()

Dim currentDirInfo As New DirectoryInfo(GetFullyQualifiedFolderPath(FilePath))

Dim folders = currentDirInfo.GetDirectories()

Dim files = currentDirInfo.GetFiles()

Dim fsItems As New List(Of FileSystemItem)(folders.Length + files.Length)

For Each file In files

fsItems.Add(New FileSystemItem(file))

grvObject.DataSource = fsItems

grvObject.DataBind()

End Sub

#End Region

#Region "Event Handles"

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

Try

If Page.IsPostBack = False Then

SetFilePath()

BindData()

End If

Catch ex As Exception

End Try

End Sub

Private Sub DownloadFile(ByVal filepath As String)

If filepath <> "" Then

Dim file As New System.IO.FileInfo(filepath)

If file.Exists Then

Response.Clear()

Response.ClearContent()

Response.ClearHeaders()

Response.BufferOutput = False

Response.ContentType = "application/zip"

Response.AddHeader("content-disposition", "attachment; filename=" + file.Name)

Response.WriteFile(file.FullName)

file.Delete()

Response.End()

Else

Response.Write("This file does not exist.")

End If

Else

Response.Write("Please provide a file to download.")

End If

End Sub

Private Sub cmdDownload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdDownload.Click

Try

SetFilePath()

Dim intCount As Integer = grvObject.Rows.Count

Dim chkSelect As CheckBox

Dim lblLabel As Label

Dim i As Integer

If intCount > 0 Then

Dim sZipFileName As String = String.Format("Zip_{0}.zip", DateTime.Now.ToString("yyyy-MM-dd-HHmmss"))

Dim s As ZipOutputStream = New ZipOutputStream(File.Create(FilePath & "\" & sZipFileName))

s.SetLevel(9)

Dim buffer() As Byte

ReDim buffer(4096)

For i = 0 To intCount - 1

chkSelect = CType(grvObject.Rows(i).FindControl("chkSelect"), CheckBox)

lblLabel = CType(grvObject.Rows(i).FindControl("lblFileName"), Label)

If Not chkSelect Is Nothing And Not lblLabel Is Nothing Then

Dim FileName As String = ""

If Not lblLabel Is Nothing Then

FileName = lblLabel.Text

End If

If FileName <> "" AndAlso chkSelect.Checked Then

Dim entry As ZipEntry = New ZipEntry(Path.GetFileName(FileName))

entry.DateTime = DateTime.Now

s.PutNextEntry(entry)

Dim fs As FileStream = File.OpenRead(FileName)

Dim sourceBytes As Integer = 1

Do Until (sourceBytes <= 0)

sourceBytes = fs.Read(buffer, 0, buffer.Length)

s.Write(buffer, 0, sourceBytes)

Loop

fs.Close()

End If

s.Finish()

s.Close()

DownloadFile(FilePath & "\" & sZipFileName)

End If

Catch ex As Exception

Exit Sub

Finally

End Try

End Sub

#End Region

End Class

End Namespace

Chạy Project, mỗi khi lựa chọn file và kích nút Download, toàn bộ các file được chọn sẽ được ZIP thành 1 file và Download về PC của người dùng.

Chúc các bạn thành công!

Quang Bình

News Ticker