Add all files form Folder to ZipFile using C# and VB.Net in ASP.Net

Hi amritha444,

Instead of adding files directly using AddFile, add binary data using AddEntry to Zip.

Refer below code.

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { 
            new DataColumn("Id", typeof(int)),
            new DataColumn("Name", typeof(string)),
            new DataColumn("Country",typeof(string)) });
        dt.Rows.Add(1, "John Hammond", "United States");
        dt.Rows.Add(2, "Mudassar Khan", "India");
        dt.Rows.Add(3, "Suzanne Mathews", "France");
        dt.Rows.Add(4, "Robert Schidner", "Russia");

        gvUsers.DataSource = dt;
        gvUsers.DataBind();
    }
}

protected void ExportToZip(object sender, EventArgs e)
{
    List<string> folderPaths = new List<string>();
    for (int i = 0; i < gvUsers.Rows.Count; i++)
    {
        DataTable dt = new DataTable();
        foreach (TableCell cell in gvUsers.HeaderRow.Cells)
        {
            dt.Columns.Add(cell.Text);
        }

        GridViewRow row = gvUsers.Rows[i] as GridViewRow;
        dt.Rows.Add();
        for (int j = 0; j < row.Cells.Count; j++)
        {
            dt.Rows[dt.Rows.Count - 1][j] = row.Cells[j].Text;
        }
        string folderPath = Server.MapPath("~/Files/");
        if (!Directory.Exists(folderPath))
        {
            Directory.CreateDirectory(folderPath);
        }
        string fileName = folderPath + "File" + i + ".xlsx";
        SaveInExcel(dt, fileName);
        folderPaths.Add(fileName);
    }

    ZipFile zip = new ZipFile();
    zip.AlternateEncodingUsage = ZipOption.AsNecessary;
    foreach (string filepath in folderPaths)
    {
        byte[] bytes = File.ReadAllBytes(filepath);
        string fileName = Path.GetFileName(filepath);
        zip.AddEntry(fileName, bytes);
    }
    foreach (string filepath in folderPaths)
    {
        if (File.Exists(filepath))
        {
            File.Delete(filepath);
        }
    }
    Response.Clear();
    Response.BufferOutput = false;
    string zipName = String.Format("Zip_{0}.zip", DateTime.Now.ToString("yyyy-MMM-dd-HHmmss"));
    Response.ContentType = "application/zip";
    Response.AddHeader("content-disposition", "attachment; filename=" + zipName);
    zip.Save(Response.OutputStream);      
    Response.End();
}

private void SaveInExcel(DataTable dt, string fileName)
{
    XLWorkbook wb = new XLWorkbook();
    wb.Worksheets.Add(dt, "ExcelFile");
    wb.SaveAs(fileName);
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = New DataTable
        dt.Columns.AddRange(New DataColumn() {
                            New DataColumn("Id", GetType(System.Int32)),
                            New DataColumn("Name", GetType(System.String)),
                            New DataColumn("Country", GetType(System.String))})
        dt.Rows.Add(1, "John Hammond", "United States")
        dt.Rows.Add(2, "Mudassar Khan", "India")
        dt.Rows.Add(3, "Suzanne Mathews", "France")
        dt.Rows.Add(4, "Robert Schidner", "Russia")
        gvUsers.DataSource = dt
        gvUsers.DataBind()
    End If
End Sub

Private Sub SaveInExcel(ByVal dt As DataTable, ByVal fileName As String)
    Dim wb As XLWorkbook = New XLWorkbook
    wb.Worksheets.Add(dt, "ExcelFile")
    wb.SaveAs(fileName)
End Sub

Protected Sub ExportToZip(ByVal sender As Object, ByVal e As EventArgs)
    Dim folderPaths As List(Of String) = New List(Of String)
    Dim i As Integer = 0
    Do While (i < gvUsers.Rows.Count)
        Dim dt As DataTable = New DataTable
        For Each cell As TableCell In gvUsers.HeaderRow.Cells
            dt.Columns.Add(cell.Text)
        Next
        Dim row As GridViewRow = CType(gvUsers.Rows(i), GridViewRow)
        dt.Rows.Add()
        Dim j As Integer = 0
        Do While (j < row.Cells.Count)
            dt.Rows((dt.Rows.Count - 1))(j) = row.Cells(j).Text
            j = (j + 1)
        Loop

        Dim folderPath As String = Server.MapPath("~/Files/")
        If Not Directory.Exists(folderPath) Then
            Directory.CreateDirectory(folderPath)
        End If

        Dim fileName As String = (folderPath & "File" & i & ".xlsx")
        SaveInExcel(dt, fileName)
        folderPaths.Add(fileName)
        i = (i + 1)
    Loop

    Dim zip As ZipFile = New ZipFile()
    zip.AlternateEncodingUsage = ZipOption.AsNecessary
    For Each filepath As String In folderPaths
        Dim bytes As Byte() = File.ReadAllBytes(filepath)
        Dim fileName As String = Path.GetFileName(filepath)
        zip.AddEntry(fileName, bytes)
    Next

    For Each filepath As String In folderPaths

        If File.Exists(filepath) Then
            File.Delete(filepath)
        End If
    Next
    Response.Clear()
    Response.BufferOutput = False
    Dim zipName As String = String.Format("Zip_{0}.zip", DateTime.Now.ToString("yyyy-MMM-dd-HHmmss"))
    Response.ContentType = "application/zip"
    Response.AddHeader("content-disposition", ("attachment; filename=" + zipName))
    zip.Save(Response.OutputStream)
    Response.End()
End Sub