Question

I’v some query about my code. Im a beginner in VB2005, I js want to add some item n my dgCart(DataGrid) from my txtISBNInfo & txtTitleInfo (Textbox). Upon addin it, the itemx must be limited into 3, and the dgCart(DataGrid) should not contain any doubling or duplication ov items. What should I do?
In my for each it will to determine if it exists and then only after it has determined it doesn’t exist, add a new row. By that I mean… Here I show you my code but regrettably it doesn’t work…

Private Sub btnAddToCart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddToCart.Click

    Dim IsFound As Boolean = False

    Dim Count As Integer = dgCart.Rows.Count

    For Each dgvRow As DataGridViewRow In dgCart.Rows

        If dgvRow.Cells("clmISBN").Value.ToString = txtISBNInfo.Text Then
            IsFound = True
            'at this point you can actually exit for because you have the info you need.

        End If
    Next

    If IsFound Then
        dgCart.Rows.Add(txtISBNInfo.Text, txtTitleInfo.Text)
    Else
        MsgBox("Already in list!")
    End If

End Sub

Answer 1

I think you pretty much had it but you had the if statement at the end swapped

Private Sub btnAddToCart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddToCart.Click
    ''//Set a flag saying that we have not found the row yet
    Dim IsFound As Boolean = False

    ''//Loop through each row
    For Each dgvRow As DataGridViewRow In dgCart.Rows
        ''//Compare the cell to our inputed
        If dgvRow.Cells("clmISBN").Value.ToString = txtISBNInfo.Text Then
            ''//Flag the we found the item
            IsFound = True
            ''//No need to loop through the remaining rows, exit the loop
            Exit For    
        End If
    Next

    ''If the item was found in the datagrid
    If IsFound Then
        MsgBox("Already in list!")
    Else ''//Otherwise
        ''//Add it
        dgCart.Rows.Add(txtISBNInfo.Text, txtTitleInfo.Text)
    End If
End Sub