DataGridView

[sc5502]

Background- Front end Visual Studio 2013 using visual basic, back end MS SQL Server 2012 and I am new to visual basic.

I am using a data grid view. The code is below. The line of code

DGV_CurrentRatings.Columns.Item("ID_Evaluations").Width = 0

generates the following error message: "Object reference not set to an instance of an object." What am I doing wrong?

 Dim strSQL As String
 
        strSQL = "Select * FROM Evaluations WHERE FY='" & my_CurrentFY & "' AND MD_Delete='0' AND ID_Supplier=" & my_IDSupplier & " Order By FY DESC, QTR"
 
 
        Try
            Dim connectionString As String = SQL_ConnectionStr2
 
            Dim connection As New SqlConnection(connectionString)
            Dim dataadapter As New SqlDataAdapter(strSQL, connection)
            Dim ds As New DataSet()
            connection.Open()
            dataadapter.Fill(ds, "Authors_table")
            connection.Close()
            DGV_CurrentRatings.DataSource = ds
            DGV_CurrentRatings.DataMember = "Authors_table"
            DGV_CurrentRatings.Columns.Item("ID_Evaluations").Width = 0
            DGV_CurrentRatings.Columns.Item("ID_Supplier").Width = 0
            DGV_CurrentRatings.Columns.Item("FYStatus").Width = 0
            DGV_CurrentRatings.Columns.Item("StatusDateTime").Width = 0
            DGV_CurrentRatings.Columns.Item("EvalStatus").Width = 0
            DGV_CurrentRatings.Columns.Item("EvalStatusDate").Width = 0
            DGV_CurrentRatings.Columns.Item("FY").Width = 40
 
            With DGV_CurrentRatings.ColumnHeadersDefaultCellStyle
                .Font = New Font(DGV_CurrentRatings.Font, FontStyle.Bold)
            End With
 
        Catch EX As Exception
            MsgBox(EX.Message)
            Return False
            Exit Function
        End Try

[Luk3r]

The real meaning is that you're trying to change the property of an object that does not exist or is null. This just means that the columns were either never created or the name of the column is not a match.

[sc5502]

The query does return rows and the column is spelled correctly, if this is what you mean.

[Luk3r]

That is, in fact, what I meant. The fact remains that your code thinks your column doesn't exist. The way you're trying to modify the column width is by means of checking the column header text. You could always try to use an integer in place of the header text for troubleshooting.

DataGridView1.Columns.Item(0).Width = 0