Removing empty columns, also changes row count with code, Why?

It applies a filter to the dataview (empty column filter) and dataview then only contains rows where that column is empty. Datatable still contains all the rows. So set the datatable as the datasource not dataview.

Or remove the filter on the defaultview AFTER running your code to show all the rows.

I am setting the datatable as the datasource. How do you remove the filter on the defaultview after running the code.

        Dim Col As DataColumn
        For i As Integer = dt.Columns.Count - 1 To 0 Step -1
            Col = dt.Columns(i)
            If Col.DataType Is GetType(String) Then
                d = dt.DefaultView.Count
                dt.DefaultView.RowFilter = Col.ColumnName & "<>''"
                If dt.DefaultView.Count = 0 Then
                    dt.Columns.Remove(Col)
                End If
            End If
        Next

        dv = New DataView(dt)
        datagrid.DataSource = dt
        DataBind()

Do you not need that on web form? "dv = New DataView(dt)" I've always put that in my code, but maybe it's only needed on windows form datagrid.

Its not needed anywhere unless you need to filter and assign the filtered data to a grid or other control.