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adwooley2

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Datagridview - updating problems part II

Sancler, I hope you're out there somewhere....

I have a datagrid that's bound directly to a dataset. I also have a button on my form with following eventhandler:
 
Private Sub btnUpdate_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        DataGridView1.BindingContext(ds.Tables(0)).EndCurrentEdit()
        Try
            For Each row As DataRow In ds.Tables(0).Rows
                If row.RowState = DataRowState.Modified Then
                    db.CropMasterUpdate(IIf(IsDBNull(row.Item(0)), "", row.Item(0)), _
                                            IIf(IsDBNull(row.Item(1)), "", row.Item(1)), _
                                            IIf(IsDBNull(row.Item(2)), "", row.Item(2)), _
                                            IIf(IsDBNull(row.Item(3)), "", row.Item(3)), _
                                            IIf(IsDBNull(row.Item(4)), "", row.Item(4)), _
                                            IIf(IsDBNull(row.Item(5)), 0, row.Item(5)), _
                                            IIf(IsDBNull(row.Item(6)), 0, row.Item(6)), _
                                            IIf(IsDBNull(row.Item(7)), 0, row.Item(7)), _
                                            IIf(IsDBNull(row.Item(8)), 0, row.Item(8)))

                End If
                BindGrid()
            Next
         Catch ex As Exception
        End Try
    End Sub

I also have textboxes and a populate item which goes through selected rows and fills in the cells:

Private Sub btnPopulate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPopulate.Click
        Me.Cursor = Cursors.WaitCursor
        If Me.DataGridView1.SelectedRows.Count > 0 Then
            For Each row As DataGridViewRow In Me.DataGridView1.SelectedRows
                row.Cells(5).Value = IIf(Me.txtTop.Text = "", 0, Me.txtTop.Text))
                row.Cells(6).Value = IIf(Me.txtBottom.Text = "", 0, Me.txtBottom.Text)
                row.Cells(7).Value = IIf(Me.txtLeft.Text = "", 0, Me.txtLeft.Text)
                row.Cells(8).Value = IIf(Me.txtRight.Text = "", 0, Me.txtRight.Text)

                ds.AcceptChanges()
            Next
        End If
        Me.Cursor = Cursors.Default
    End Sub


However, when I make a change on a single row and hit update, it doesn't pick up the current row as having been editted (and therefore doesn't update the database).  The row.RowState shows "unchanged".  Sometimes when I make a bulk update to the datagridview, it doesn't even pick up those changes for reasons I do not know.
Also, when I make a change directly in the Datagridview, it sometimes picks up the change and saves... sometimes doesn't.  Is there a sure-fire way to pick up all the changes to the datagridview so that I can save to the database?  

This is rather urgent.  All replies are appreciated.
Regards,
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Sancler
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newyuppie
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5) you could set the column's default value in the datatable to "0" instead of checking for nulls using the IIF. this way you will get the 0 automatically. this for integer or numerical columns. on the other hand set the string column's default value to string.empty.
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adwooley2

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Appreciate all the attention :)   And thanks for being there Sancler!
I had a funny feeling about that ds.AcceptChanges().  Removed that.
For newyuppie,
1) Understood
2) I had more to the Try structure, but for now, will remove
3) I am passing updates to a stored procedure. Don't know if a da can take updates and run it through an sp.
Now my update code looks like below (null checking will be changed per newyuppie's suggestion later).  Once I removed the Try structure, it revealed an error where the ds.Tables(0).GetChanges returned a NullReferenceException.   In other words, if I pressed the Update button when there were no changes, it caused a NullReferenceException.  So, by checking "If Not tbl Is Nothing" then it seems to operate correctly.  (Don't know if that makes sense).

    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        DataGridView1.BindingContext(ds.Tables(0)).EndCurrentEdit()
        Dim tbl As DataTable
        tbl = ds.Tables(0).GetChanges
        If Not tbl Is Nothing Then
            For Each row As DataRow In tbl.Rows
                db.CropMasterUpdate(IIf(IsDBNull(row.Item(0)), "", row.Item(0)), _
                                            IIf(IsDBNull(row.Item(1)), "", row.Item(1)), _
                                            IIf(IsDBNull(row.Item(2)), "", row.Item(2)), _
                                            IIf(IsDBNull(row.Item(3)), "", row.Item(3)), _
                                            IIf(IsDBNull(row.Item(4)), "", row.Item(4)), _
                                            IIf(IsDBNull(row.Item(5)), 0, row.Item(5)), _
                                            IIf(IsDBNull(row.Item(6)), 0, row.Item(6)), _
                                            IIf(IsDBNull(row.Item(7)), 0, row.Item(7)), _
                                            IIf(IsDBNull(row.Item(8)), 0, row.Item(8)))

            Next
        End If

        BindGrid()
    End Sub

Again, I appreciate your help.  Let's hope there isn't a "part III" to this saga.
Regards,
ADWooley