Add expression column

[vwalla]

Is there anything qrong with this code?

Sub showExtended()
        Dim dcTotal As New Data.DataColumn("totalPrice", System.Type.GetType("System.Decimal"))
        dcTotal.Expression = "PriceEach * QTY"
    End Sub

My load event

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'DatagridDataSet.tblData' table. You can move, or remove it, as needed.
        Me.TblDataTableAdapter.Fill(Me.DatagridDataSet.tblData)
        showTotal()
        showExtended()
    End Sub

I do not get any errors when placed in the formLoad event, but there is also no "computed" value in the column for the rows.

I am using vb 2005 express.

Thanks

 

[chrissie1]

you need to add the column to your dataset for it to work

Sub showExtended()
        Dim dcTotal As New Data.DataColumn("totalPrice", System.Type.GetType("System.Decimal"))
        dcTotal.Expression = "PriceEach * QTY"
        me.datagriddatasettables(0).columns.add(dctotal)
    End Sub

Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]

 

[vwalla]

I get the following error:

"Object reference not set to an instance of an object."

??

Thanks

 

[chrissie1]

this

me.datagriddatasettables(0).columns.add(dctotal)

should be

me.datagriddataset.tbldata.columns.add(dctotal)


Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]

 

[vwalla]

Getting same error.

"Object reference not set to an instance of an object."

I am at a loss.

Thanks

 

[chrissie1]

where do you get the error.

if you do a watch wich of the objects is nothing.

Christiaan Baes
Belgium

I just like this --> [Wiggle] [Wiggle]

 

[vwalla]

This is where the error is.

Me.DatagridDataSet.Tables(0).Columns("totalPrice").Expression = "PriceEach * QTY"

The exception is "NullReferenceException was Unhandled"

Thanks

 

[vwalla]

I found my answer.

It was simple.

http://whidbey.msdn.microsoft.com/l...html/47e14652-2b8b-4bda-8f9d-bc0721be9260.asp

Thanks very much for your help.

Vwalla