How to import and Export to excel?, ASP.NET samples and tutorials

How to import and Export to excel?, ASP.NET samples and tutorials:
How to import and Export to excel?

This example shows how you can import the content of an excel sheet to a datagrid and export from a datagrid to an excel sheet, no automation is required.
The application is explained with the help of File Field HTML component. Author: ManojRajan



Posted Date: 20 Apr, 2004 .NET Classes used :

System.Data.DataSetSystem.Data.OleDb.OleDbDataAdapterSystem.Data.OleDb.System.IO.StringWriterSystem.Web.UI.HtmlTextWriter
This application uses a FileField (UploadFile)(HTML control) , One label (lblMessage), Button (btnSubmit), Button (btnExportToExcel), DataGrid (DataGrid1), This also explains how to upload a file.

Imports System
Imports System.Data
Imports System.Data.OleDb
Imports System.IO

Code :

Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
Dim intFileNameLength As Integer
Dim strFileNamePath As String
Dim strFileNameOnly As String

If Not (UploadFile.PostedFile Is Nothing) Then
strFileNamePath = UploadFile.PostedFile.FileName

intFileNameLength = InStr(1, StrReverse(strFileNamePath), "\")

strFileNameOnly = Mid(strFileNamePath, (Len(strFileNamePath) - intFileNameLength) + 2)
Dim paths = Server.MapPath("/excelreading/")

paths = paths & "Excel/"

'If File.Exists(paths & strFileNameOnly) Then
'lblMessage.Text = "Image of Similar name already Exist,Choose other name"
'Else
If UploadFile.PostedFile.ContentLength > 40000 Then
lblMessage.Text = "The Size of file is greater than 4 MB"
ElseIf strFileNameOnly = "" Then
Exit Sub
Else
strFileNameOnly = Session("AdminID") & "-" & Session("Acountry") & "-" & Format(Date.Today, "mm-dd-yyyy").Replace("/", "-") & ".xls"
UploadFile.PostedFile.SaveAs(paths & strFileNameOnly)
lblMessage.Text = "File Upload Success."
Session("Img") = strFileNameOnly
End If
End If
'End If

Dim myDataset As New DataSet()
Dim strConn As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & Server.MapPath("/excelreading/") & "excel/" & strFileNameOnly & ";" & _
"Extended Properties=Excel 8.0;"

''You must use the $ after the object you reference in the spreadsheet
Dim myData As New OleDbDataAdapter("SELECT * FROM [Sheet1$]", strConn)
myData.TableMappings.Add("Table", "ExcelTest")
myData.Fill(myDataset)

DataGrid1.DataSource = myDataset.Tables(0).DefaultView
DataGrid1.DataBind()
End Sub

Private Sub btnExportToExcel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExportToExcel.Click
' Set the content type to Excel.
Response.ContentType = "application/vnd.ms-excel"
' Remove the charset from the Content-Type header.
Response.Charset = ""
' Turn off the view state.
Me.EnableViewState = False

Dim tw As New System.IO.StringWriter()
Dim hw As New System.Web.UI.HtmlTextWriter(tw)

' Get the HTML for the control.
DataGrid1.RenderControl(hw)
' Write the HTML back to the browser.
Response.Write(tw.ToString())
' End the response.
Response.End()
lblMessage.Text = "For any more information , feel free to contact ...!!!"
End Sub