Upload a CSV file into a Gridview

You have a CSV file and you would like to display it in a Gridview.

This bit of code was born out of a desire to allow user's to see their CSV contents inside of a Gridview. Once the user had a chance to see it they could click a button to move to the next step.

This following code will take the CSV and turn it into a dataTable that will be able then bound to a Gridview. This makes it easy to further manipulate your data or even saving the dataTable to session for future use.

THE CODE:

1. Drop a FileUpload control on your canvas as well as a Button for submitting the file and a Gridview control.
2. Then add the System.IO, your Variables, and the Click Event to the Button.
   
   Imports System.IO

   Partial Public Class _Default
   Inherits System.Web.UI.Page

   Dim streamRdr As StreamReader
   Dim fileLines As String()
   Dim line As String

   Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click

   If FileUpload1.HasFile Then

   Dim fileExt As String

   fileExt = System.IO.Path.GetExtension(FileUpload1.FileName)

   If fileExt = ".csv" Or fileExt = ".CSV" Then

   'Make variables needed
   Dim objStream As Stream
   Dim fileLen As Integer

   'Get the length of the file.
   fileLen = FileUpload1.PostedFile.ContentLength

   'Create a byte array to hold the contents of the file.
   Dim Input(fileLen) As Byte

   'Move byte array into a stream, then start it at beginning and pass it to method.
   objStream = FileUpload1.PostedFile.InputStream
   objStream.Read(Input, 0, fileLen)
   objStream.Position = 0

   'Manage File
   importToDG(objStream)

   End If

   End If

   End Sub

   NOTICE above, we verify that we are getting a CSV file in and then we create a stream to hold the incoming file.
   
   We then get the length, create a byte array to temporarily hold the contents, move it into the stream, then reset the stream's position.
   
   Finally we call our next method 'importToDG' and send in the stream.

3. Create the import Sub - you will need to create a Datatable, a row, and the columns that match your CSV. You need to put your CSV info into a datatable for the Gridview can bind to it.
   
   Private Sub importToDG(ByVal fileStream As Stream)

   streamRdr = New StreamReader(FileStream)

   Dim myDTable As DataTable = New DataTable
   Dim myDRow As DataRow = myDTable.NewRow
   Dim schoolID, distID, schoolName, Address, Address2, Phone, City, State, Zip _
   As New DataColumn
   schoolID.ColumnName = "SchoolID"
   distID.ColumnName = "DistrictID"
   Phone.ColumnName = "Phone"
   schoolName.ColumnName = "schoolName"
   Address.ColumnName = "Address"
   Address2.ColumnName = "Address2"
   City.ColumnName = "City"
   State.ColumnName = "State"
   Zip.ColumnName = "Zip"
   myDTable.Columns.Add(schoolID)
   myDTable.Columns.Add(distID)
   myDTable.Columns.Add(schoolName)
   myDTable.Columns.Add(Address)
   myDTable.Columns.Add(Address2)
   myDTable.Columns.Add(Phone)
   myDTable.Columns.Add(City)
   myDTable.Columns.Add(State)
   myDTable.Columns.Add(Zip)

   'Now set the streamreader back to beginning.
   streamRdr.DiscardBufferedData()
   streamRdr.BaseStream.Seek(0, SeekOrigin.Begin)
   streamRdr.BaseStream.Position = 0

   Dim i As Integer = 0 'Skip the first row.

   While Not streamRdr.EndOfStream

   line = streamRdr.ReadLine 'Read first line
   fileLines = line.Split(",") 'Split the line up by the delimeter

   If i > 0 Then
   myDRow.ItemArray = fileLines
   myDTable.Rows.Add(myDRow)
   myDRow = myDTable.NewRow
   End If

   i += 1

   End While

   GridView1.DataSource = myDTable
   GridView1.DataBind()

   End Sub

   End Class

Take notice that above I skipped the first row of my file. That is because our CSV's had column names as the first row... DO NOT DO THIS
unless you need to skip the row for a reason.

See full detail: http://www.vbdotnetheaven.com/UploadFile/tvance929/106182009115344AM/1.aspx