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vb.net, datagridview, combobox

I have a datagridview with multiple columns. Two of the columns are comboboxes. The entries in ComboBox2 is based on the entry in ComboBox1. For example, ComboBox1 contains values of 10, 20, 30. Keeping in mind that the datagridview can have multiple rows, when ComboBox1 is set to 10, ComboBox2 should have values of A1, A2, and A3, when ComboBox1 is set to 20, ComboBox2 should have values of B1, B2, and B3, etc. I don't believe I can accomplish this. Therefore, I have two questions.
1. Am I correct?
2. Does anyone have a suggestion of how to accomplish this function?
Thanks.

nepaluz

declare to lists of string with your values and set the combobox values' datasource to the lists

then you wil have to handle the selectedvaluechanged or selectedindexchanged of combobox1 to populate combobox2.

This is straight foward with mere comboboxes, however with the datagridviewcomboboxes, you will have to handle these events and filter for the grid column index etc

I have some code for you below. It may need some sprucing up bit it does what you asked for. Start a new project and add a datagridview with two comboboxcolumns, then copy the code and run

Public Class Form1
    Dim List1 As New List(Of Integer) From {10, 20, 30}
    Dim List2 As New List(Of String) From {"A1", "A2", "A3"}
    Dim List3 As New List(Of String) From {"B1", "B2", "B3"}
    Dim List4 As New List(Of String) From {"C1", "C2", "C3"}

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim c1 = DirectCast(Me.DataGridView1.Columns(0), DataGridViewComboBoxColumn)
        c1.DataSource = List1


    End Sub

    Private Sub DataGridView1_CellValueChanged(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellValueChanged
        Try
            If e.ColumnIndex = 0 Then
                Dim c2 = DirectCast(Me.DataGridView1.Item(1, e.RowIndex), DataGridViewComboBoxCell)
                c2.Items.Clear()
                Select Case Me.DataGridView1.Item(0, e.RowIndex).Value.ToString
                    Case "10"
                        c2.DataSource = List2
                    Case "20"
                        c2.DataSource = List3
                    Case "30"
                        c2.DataSource = List4
                End Select
            End If
        Catch ex As Exception

        End Try

    End Sub

    Private Sub DataGridView1_DataError(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewDataErrorEventArgs) Handles DataGridView1.DataError

    End Sub
End Class

Open in new window

You need the last handler (data error) because when you start the form the gridview isnot populated and this generates a data error.

DG.png

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PagodNaUtak

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Joe Kaminski

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Keep in mind that the user will populate the values in ComboBox1 and ComboBox2, i.e., there could be three values in ComboBox1 or 20 values. the same for ComboBox2. Are these examples handling this? Thanks.

nepaluz

pago's suggestion works better, so I suggest you look at it rather than mine.
On whether the user has to input more values, well you never asked for that, but yes, you can incorporate that too!