.CSV to DataGridView Rows coming up blank in VB.NET

Question

Here is the CSV data I am trying to import into my VB.NET app:

Raw Data

But when I run it through the app it only populates the last row:

Output

Answer 1

I would not suggest trying to read the data via a StreamReader, instead use the OleDb class while passing the connection string for a CSV file.

Here is a quick example of a function that returns a DataTable based on the contents of the CSV file:

Private Function ConvertCSVToDataTable(ByVal path As String) As DataTable
    Dim dt As DataTable = New DataTable()
    Using con As OleDb.OleDbConnection = New OleDb.OleDbConnection()
        Try
            con.ConnectionString = String.Format("Provider={0};Data Source={1};Extended Properties=""Text;HDR=YES;FMT=Delimited""", "Microsoft.Jet.OLEDB.4.0", IO.Path.GetDirectoryName(path))
            Using cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM " & IO.Path.GetFileName(path), con)
                Using da As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(cmd)
                    con.Open()
                    da.Fill(dt)
                    con.Close()
                End Using
            End Using
        Catch ex As Exception
            Console.WriteLine(ex.ToString())
        Finally
            If con IsNot Nothing AndAlso con.State = ConnectionState.Open Then
                con.Close()
            End If
        End Try
    End Using

    Return dt
End Function

Then here is how you'd bind your DataGridView:

DataGridView1.DataSource = Me.ConvertCSVToDataTable(ofd.FileName)

Update

Since you want to specify the data type of the DataColumn, declare a DataTable and assign it to the custom function, but then go in after the fact and change the data type of the specific columns. Here is a quick (free-typed and untested) example:

Dim csv As DataTable = Me.ConvertCSVToDataTable(ofd.FileName)
With csv.Columns
    .Items(0).DataType = GetType(Int32)
    .Items(1).DataType = GetType(Int32)
    .Items(4).DataType = GetType(Int32)
    .Items(5).DataType = GetType(Int32)
End With

DataGridView1.DataSource = csv