Setting the values that can be displayed in the child combo box

[__gini2]

A tab has two combo boxes. The first one is the parent of the second one. The second one is the sub of the first one. It displays values for each item in the first combo box. That means each item in the first combo box has sub values in the second combo box.

How do I prepare the coding or set anything else (in the properties) or sth so that for each item in the parent combo box, ONLY the sub values of that parent is displayed in the second combo box.

The reason for this question is because for a parent item, the sub values of other parent items also appear in the second combo box.

[__gini2]

In a form there are 5 tabs (Tab 1 to Tab 5). Tab 2 is the subcategory of Tab 1, Tab 3 is the sub of Tab 2, Tab 3 is the sub of Tab 4 and so on. From Tab 2 onwards, there are 2 combo boxes and 1 textbox. The second combo box of each tab displays the subvalues of each value of the first combo box. And the text box displays the description for the second combo box (this is also for each tab).

By default, before any functions like editing, deleting, saving or adding new items, the first combo box of each tab will automatically display the value from the second combo box from the previous tab.(because each tab is the subcategory of the previous tab, so the first combo box of each tab from Tab 2 onwards will display the sub values of the previous tab)

But now the problem I face is that from Tab 3 onwards the first combo box does not display the value from the second combo box of the previous tab. Even the text box does not display the description of the second combo box value. I do not know why.

Please help me.

Below is the coding from the beginning and Tab 2. The coding for Tab 3 onwards is exactly the same as Tab 2, except with different variable names.

Is there anything wrong with the coding?

Imports System.Windows.Forms.DataGrid
Imports System.Data.SqlClient

Public Class InventoryMainForm
    Private CatCodeDesc As String
    Private CatCode As String
    Private WarehouseLocation As String
    Private Warehouse As String
    Private UOMCode As String
    Private subcatcode As String
    Private subcat1code As String
    Private subcat2code As String
    Private subcat3code As String
    Private AddNew As Boolean
    Dim DQcheck As New SqlCommand
    Dim DHcheck As New SqlDataAdapter
    Dim DScheck As New DataSet
    Dim Dvcheck As New DataView
    Private Sub InventoryMainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            Me.CountryTableAdapter.Fill(Me.DsSales.country)
            Me.Inv_itemsubcategoryTableAdapter.Fill(Me.dsInventory.inv_itemsubcategory)
            Me.Inv_itemlocTableAdapter.Fill(Me.dsInventory.inv_itemloc)
            Me.Inv_itemuomTableAdapter.Fill(Me.dsInventory.inv_itemuom)
            Me.Inv_itemcategoryTableAdapter.Fill(Me.dsInventory.inv_itemcategory)
            Me.Inv_itemCat3TableAdapter.Fill(Me.dsInventory.inv_itemCat3)
            Me.Inv_itemCat4TableAdapter.Fill(Me.dsInventory.inv_itemCat4)
            Me.Inv_itemCat5TableAdapter.Fill(Me.dsInventory.inv_itemCat5)
        Catch ex As Exception
            MessageBox.Show(ex.Message, Me.Text + " FrmLoad", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Sub


 
    '=========Inventory Item Sub Category===========
    Private Sub subcatBindingNavigatorAddNewItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcatBindingNavigatorAddNewItem.Click
        subcatcode = cmbsubcatcode.SelectedValue
        cmbsubcatcode.Visible = False
        txtsubcat.Visible = True
        cmbitemcat.Text = ""
        txtsubcat.Text = ""
        txtsubcatdesc.Text = ""
        subcat(False)
        AddNew = True
        cmbitemcat.Focus()
    End Sub

    Private Sub subcat(ByVal check As Boolean)

        dgsubcategory.Enabled = check
        BindingNavigatorMoveFirstItem1.Enabled = check
        BindingNavigatorMoveLastItem1.Enabled = check
        BindingNavigatorMoveNextItem1.Enabled = check
        BindingNavigatorMovePreviousItem1.Enabled = check
        BindingNavigatorCountItem1.Enabled = check
        BindingNavigatorPositionItem1.Enabled = check

        subcatBindingNavigatorRefreshItem.Visible = check
        subcatBindingNavigatorAddNewItem.Visible = check
        subcatBindingNavigatorEditItem.Visible = check
        cmbsubcatcode.Visible = check
        txtitemcat.Visible = check
        If check = False Then
            check = True
            subcatBindingNavigatorDeleteItem.Text = "Cancel"
        Else
            check = False
            subcatBindingNavigatorDeleteItem.Text = "Delete"
        End If

        subcatBindingNavigatorSaveItem.Visible = check
        txtsubcat.Visible = check
        cmbitemcat.Visible = check
        txtsubcatdesc.Enabled = check
    End Sub

    Private Sub subcatBindingNavigatorEditItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcatBindingNavigatorEditItem.Click
        If dgsubcategory.RowCount > 0 Then
            subcatcode = cmbsubcatcode.SelectedValue
            subcat(False)
            txtsubcat.Enabled = False
            cmbitemcat.Enabled = False
            cmbitemcat.Focus()
        Else
            MessageBox.Show("No record to edit.", Me.Text + " - Item Category Level 2", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End If
    End Sub

    Private Sub subcatBindingNavigatorDeleteItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcatBindingNavigatorDeleteItem.Click
        Try
            If dgsubcategory.RowCount > 0 Then
                If subcatBindingNavigatorDeleteItem.Text = "Delete" Then
                    If MessageBox.Show("Are you sure to delete this record?", "Confirm", MessageBoxButtons.YesNo, MessageBoxIcon.Information, MessageBoxDefaultButton.Button2) = Windows.Forms.DialogResult.Yes Then
                        gSQLstr = "SELECT COUNT(iim_subcat) FROM inv_itemmaster WHERE  iim_subcat = " & cSQL(cmbsubcatcode.Text) & ""
                        If gSQLcon.State = ConnectionState.Closed Then
                            gSQLcon.Open()
                        End If
                        DQcheck.Connection = gSQLcon
                        DQcheck.CommandText = gSQLstr
                        DHcheck.SelectCommand = DQcheck
                        DHcheck.Fill(DScheck, ("subcat_list"))
                        Dvcheck.Table = DScheck.Tables("subcat_list")
                        If Dvcheck.Table.Rows(0).Item(0) > 0 Then
                            MessageBox.Show("Record cannot be deleted!", Me.Text + " - Item Category Level 2", MessageBoxButtons.OK, MessageBoxIcon.Information)
                        Else
                            InvitemsubcategoryBindingSource.RemoveCurrent()
                            Inv_itemsubcategoryTableAdapter.Update(dsInventory)
                            MessageBox.Show("Record has been deleted.", "Delete", MessageBoxButtons.OK, MessageBoxIcon.Information)
                        End If
                        DScheck.Clear()
                        gSQLcon.Close()
                    End If
                Else
                    If AddNew = True Then
                        AddNew = False
                    End If
                    subcat(True)
                    txtsubcatdesc.Enabled = False
                    refreshsubcat()
                    cmbsubcatcode.SelectedValue = subcatcode

                End If
            Else
                MessageBox.Show("No record to delete.", Me.Text + " - Item Category Level 2", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If

        Catch ex As Exception
            MessageBox.Show(ex.Message, Me.Text + " - Item Category Level 2(Delete)", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Sub

    Private Sub subcatBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcatBindingNavigatorSaveItem.Click
        Dim strmsg As String = ""
        Try
            If MessageBox.Show("Save Item?", "Save", MessageBoxButtons.YesNo, MessageBoxIcon.Information, MessageBoxDefaultButton.Button2) = Windows.Forms.DialogResult.Yes Then
                If AddNew = True Then
                    If txtsubcat.Text.Trim = "" Then
                        strmsg = strmsg & "Required field - Category Code." & vbCrLf
                    Else
                        gSQLstr = "SELECT COUNT(iis_code) FROM inv_itemsubcategory WHERE  iis_code = " & cSQL(txtsubcat.Text) & ""
                        If gSQLcon.State = ConnectionState.Closed Then
                            gSQLcon.Open()
                        End If
                        DQcheck.Connection = gSQLcon
                        DQcheck.CommandText = gSQLstr
                        DHcheck.SelectCommand = DQcheck
                        DHcheck.Fill(DScheck, ("subcat_list"))
                        Dvcheck.Table = DScheck.Tables("subcat_list")


                        If Dvcheck.Table.Rows(0).Item(0) > 0 Then
                            strmsg = strmsg & "Required field - Category Code already exits, please assign another Category Code!" & vbCrLf
                        End If
                        DScheck.Clear()
                        gSQLcon.Close()
                    End If
                End If
                If cmbitemcat.Text.Trim = "" Then
                    strmsg = strmsg & "Required field - Level 1 Category." & vbCrLf
                End If
                If txtsubcatdesc.Text.Trim = "" Then
                    strmsg = strmsg & "Required field - Description." & vbCrLf
                End If
                If strmsg = "" Then
                    If AddNew = True Then
                        dsInventory.inv_itemsubcategory.Addinv_itemsubcategoryRow(Trim(txtsubcat.Text), txtsubcatdesc.Text, cmbitemcat.Text)
                        Inv_itemsubcategoryTableAdapter.Update(dsInventory.inv_itemsubcategory)
                        Inv_itemsubcategoryTableAdapter.Fill(dsInventory.inv_itemsubcategory)
                        AddNew = False
                    Else
                        InvitemsubcategoryBindingSource.EndEdit()
                        Inv_itemsubcategoryTableAdapter.Update(dsInventory.inv_itemsubcategory)
                    End If
                    MessageBox.Show("Record saved", "Save", MessageBoxButtons.OK, MessageBoxIcon.None)
                    subcat(True)
                    cmbsubcatcode.Enabled = True
                    cmbsubcatcode.SelectedValue = subcatcode
                Else
                    MessageBox.Show(strmsg, Me.Text + " -Item Category Level 2", MessageBoxButtons.OK, MessageBoxIcon.Information)
                End If
            End If
        Catch ex As Exception
            If ex.Message.Contains("Column 'iis_code, iis_itemcode' is constrained to be unique. ") = True Then
                MessageBox.Show("The code already exits, please assign another code!", Me.Text + " - Item Category Level 2", MessageBoxButtons.OK, MessageBoxIcon.Information)
                Exit Sub
            Else
                MessageBox.Show(ex.Message, Me.Text + " - Item Category Level 2(Save)", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If
        End Try
    End Sub

    Private Sub subcatBindingNavigatorRefreshItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcatBindingNavigatorRefreshItem.Click
        refreshsubcat()
    End Sub

    Private Sub refreshsubcat()
        Try
            Inv_itemsubcategoryTableAdapter.Fill(dsInventory.inv_itemsubcategory)
        Catch ex As Exception
            MessageBox.Show(ex.Message, Me.Text + " - Item Category Level 2(Refresh)", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Sub

    Private Sub btnclose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnclose.Click
        Me.Close()
    End Sub

[Shuja Ali]

Can you show us how exactly you are done this. You may be missing a simple one line of code.

[__gini2]

To be more specific I am developing a system which has five tabs on 1 form (Tab 1 to Tab 5). Tab 1 is the main tab with one combo box which displays values which also will be displayed in the first combo box of Tab 2. Tab 1 also has a text box that is a description of the value in that combo box.

Tab 2 is the sub category of Tab 1. It has two combo boxes. The first combo box will display the value from Tab 1. The second combo box will display ONLY the sub values of each value from the first combo box(when selected). There is also a text box that will be disabled by default and only show the description of the second combo box value.

Tab 3 till Tab 5 do the exact same thing like Tab 2, and these are the tabs that do not work like it is explained above. (Tab 3 to Tab 5).

Below is the code for the beginning and also Tab 3. Is there anything wrong with it?

Imports System.Windows.Forms.DataGrid
Imports System.Data.SqlClient

Public Class InventoryMainForm
    Private CatCodeDesc As String
    Private CatCode As String
    Private subcatcode As String
    Private subcat1code As String
    Private subcat2code As String
    Private subcat3code As String
    Private AddNew As Boolean
    Dim DQcheck As New SqlCommand
    Dim DHcheck As New SqlDataAdapter
    Dim DScheck As New DataSet
    Dim Dvcheck As New DataView


    Private Sub InventoryMainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            Me.CountryTableAdapter.Fill(Me.DsSales.country)
            Me.Inv_itemsubcategoryTableAdapter.Fill(Me.dsInventory.inv_itemsubcategory)
            Me.Inv_itemlocTableAdapter.Fill(Me.dsInventory.inv_itemloc)
            Me.Inv_itemuomTableAdapter.Fill(Me.dsInventory.inv_itemuom)
            Me.Inv_itemcategoryTableAdapter.Fill(Me.dsInventory.inv_itemcategory)
            Me.Inv_itemCat3TableAdapter.Fill(Me.dsInventory.inv_itemCat3)
            Me.Inv_itemCat4TableAdapter.Fill(Me.dsInventory.inv_itemCat4)
            Me.Inv_itemCat5TableAdapter.Fill(Me.dsInventory.inv_itemCat5)
        Catch ex As Exception
            MessageBox.Show(ex.Message, Me.Text + " FrmLoad", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Sub

'=========Inventory Item Sub Category 1 ===========

    Private Sub subcat1BindingNavigatorAddNewItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcat1BindingNavigatorAddNewItem.Click
        subcat1code = cmb1subcatcode.SelectedValue
        cmb1subcatcode.Visible = False
        txt1subcat.Visible = True
        cmb1itemcat.Text = ""
        txt1subcat.Text = ""
        txt1subcatdesc.Text = ""
        subcat1(False)
        AddNew = True
        cmb1itemcat.Focus()
    End Sub

    Private Sub subcat1(ByVal check As Boolean)

        dgsubcategory1.Enabled = check
        BindingNavigatorMoveFirstItem2.Enabled = check
        BindingNavigatorMoveLastItem2.Enabled = check
        BindingNavigatorMoveNextItem2.Enabled = check
        BindingNavigatorMovePreviousItem2.Enabled = check
        BindingNavigatorCountItem2.Enabled = check
        BindingNavigatorPositionItem2.Enabled = check

        subcat1BindingNavigatorRefreshItem.Visible = check
        subcat1BindingNavigatorAddNewItem.Visible = check
        subcat1BindingNavigatorEditItem.Visible = check
        cmb1subcatcode.Visible = check
        txt1itemcat.Visible = check
        If check = False Then
            check = True
            subcat1BindingNavigatorDeleteItem.Text = "Cancel"
        Else
            check = False
            subcat1BindingNavigatorDeleteItem.Text = "Delete"
        End If

        subcat1BindingNavigatorSaveItem.Visible = check
        txt1subcat.Visible = check
        cmb1itemcat.Visible = check
        txt1subcatdesc.Enabled = check
    End Sub

    Private Sub subcat1BindingNavigatorEditItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcat1BindingNavigatorEditItem.Click
        If dgsubcategory1.RowCount > 0 Then
            subcat1code = cmb1subcatcode.SelectedValue
            subcat1(False)
            txt1subcat.Enabled = False
            cmb1itemcat.Enabled = False
            cmb1itemcat.Focus()
        Else
            MessageBox.Show("No record to edit.", Me.Text + " - Item Category Level 3", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End If
    End Sub

    Private Sub subcat1BindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcat1BindingNavigatorSaveItem.Click
        Dim strmsg As String = ""
        Try
            If MessageBox.Show("Save Item?", "Save", MessageBoxButtons.YesNo, MessageBoxIcon.Information, MessageBoxDefaultButton.Button2) = Windows.Forms.DialogResult.Yes Then
                If AddNew = True Then
                    If txt1subcat.Text.Trim = "" Then
                        strmsg = strmsg & "Required field - Category Code." & vbCrLf
                    Else
                        gSQLstr = "SELECT COUNT(ic3_code) FROM inv_itemCat3 WHERE  ic3_code = " & cSQL(txt1subcat.Text) & ""
                        If gSQLcon.State = ConnectionState.Closed Then
                            gSQLcon.Open()
                        End If
                        DQcheck.Connection = gSQLcon
                        DQcheck.CommandText = gSQLstr
                        DHcheck.SelectCommand = DQcheck
                        DHcheck.Fill(DScheck, ("subcat1_list"))
                        Dvcheck.Table = DScheck.Tables("subcat1_list")


                        If Dvcheck.Table.Rows(0).Item(0) > 0 Then
                            strmsg = strmsg & "Required field - Category Code already exits, please assign another Category Code!" & vbCrLf
                        End If
                        DScheck.Clear()
                        gSQLcon.Close()
                    End If
                End If
                If cmb1itemcat.Text.Trim = "" Then
                    strmsg = strmsg & "Required field - Level 3 Category." & vbCrLf
                End If
                If txt1subcatdesc.Text.Trim = "" Then
                    strmsg = strmsg & "Required field - Description." & vbCrLf
                End If
                If strmsg = "" Then
                    If AddNew = True Then
                        dsInventory.inv_itemCat3.Addinv_itemCat3Row(Trim(txt1subcat.Text), txt1subcatdesc.Text, cmb1itemcat.Text)
                        Inv_itemCat3TableAdapter.Update(dsInventory.inv_itemCat3)
                        Inv_itemCat3TableAdapter.Fill(dsInventory.inv_itemCat3)
                        AddNew = False
                    Else
                        InvitemCat3BindingSource.EndEdit()
                        Inv_itemCat3TableAdapter.Update(dsInventory.inv_itemCat3)
                    End If
                    MessageBox.Show("Record saved", "Save", MessageBoxButtons.OK, MessageBoxIcon.None)
                    subcat1(True)
                    cmb1subcatcode.Enabled = True
                    cmb1subcatcode.SelectedValue = subcat1code
                Else
                    MessageBox.Show(strmsg, Me.Text + " -Item Category Level 3", MessageBoxButtons.OK, MessageBoxIcon.Information)
                End If
            End If
        Catch ex As Exception
            If ex.Message.Contains("Column 'ic3_code, ic3_itemcode' is constrained to be unique. ") = True Then
                MessageBox.Show("The code already exits, please assign another code!", Me.Text + " - Item Category Level 3", MessageBoxButtons.OK, MessageBoxIcon.Information)
                Exit Sub
            Else
                MessageBox.Show(ex.Message, Me.Text + " - Item Category Level 3(Save)", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If
        End Try
    End Sub

    Private Sub subcat1BindingNavigatorDeleteItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcat1BindingNavigatorDeleteItem.Click
        Try
            If dgsubcategory1.RowCount > 0 Then
                If subcat1BindingNavigatorDeleteItem.Text = "Delete" Then
                    If MessageBox.Show("Are you sure to delete this record?", "Confirm", MessageBoxButtons.YesNo, MessageBoxIcon.Information, MessageBoxDefaultButton.Button2) = Windows.Forms.DialogResult.Yes Then
                        gSQLstr = "SELECT COUNT(iim_subcat1) FROM inv_itemmaster WHERE  iim_subcat1 = " & cSQL(cmb1subcatcode.Text) & ""
                        If gSQLcon.State = ConnectionState.Closed Then
                            gSQLcon.Open()
                        End If
                        DQcheck.Connection = gSQLcon
                        DQcheck.CommandText = gSQLstr
                        DHcheck.SelectCommand = DQcheck
                        DHcheck.Fill(DScheck, ("subcat1_list"))
                        Dvcheck.Table = DScheck.Tables("subcat1_list")
                        If Dvcheck.Table.Rows(0).Item(0) > 0 Then
                            MessageBox.Show("Record cannot be deleted!", Me.Text + " - Item Category Level 3", MessageBoxButtons.OK, MessageBoxIcon.Information)
                        Else
                            InvitemCat3BindingSource.RemoveCurrent()
                            Inv_itemCat3TableAdapter.Update(dsInventory)
                            MessageBox.Show("Record has been deleted.", "Delete", MessageBoxButtons.OK, MessageBoxIcon.Information)
                        End If
                        DScheck.Clear()
                        gSQLcon.Close()
                    End If
                Else
                    If AddNew = True Then
                        AddNew = False
                    End If
                    subcat1(True)
                    txt1subcatdesc.Enabled = False
                    refreshsubcat1()
                    cmb1subcatcode.SelectedValue = subcat1code

                End If
            Else
                MessageBox.Show("No record to delete.", Me.Text + " - Item Category Level 3", MessageBoxButtons.OK, MessageBoxIcon.Information)
            End If

        Catch ex As Exception
            MessageBox.Show(ex.Message, Me.Text + " - Item Category Level 3(Delete)", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Sub

    Private Sub subcat1BindingNavigatorRefreshItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles subcat1BindingNavigatorRefreshItem.Click
        refreshsubcat1()
    End Sub
    Private Sub refreshsubcat1()
        Try
            Inv_itemCat3TableAdapter.Fill(dsInventory.inv_itemCat3)
        Catch ex As Exception
            MessageBox.Show(ex.Message, Me.Text + " - Item Category Level 3(Refresh)", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Sub

[Shuja Ali]

Going forward please use CODE tags when you post code.

Coming to your question, I do not see any code written for Combo box. What you need to do is this:

On Combox's SelectIndexChange event handler, you will need to either get the child values from the database or if you already have them in a dataset/datatable, you can use Select method on these to select only those values that are child of the item that has been selected in the parent combobox. Then bind the resulting datatable to the child combo box.

[HanneSThEGreaT]

Is there anything wrong with the coding?

Yes, without [CODE] Tags, your code is impossible to read.

Next time add [CODE] Tags, like this:
[CODE]
'Insert Your Code In Here
[/CODE]

[HairyMonkeyMan]

I had to do something like that before - one combos items depended on the selection of the previous combo.

I don't know exactly what your trying to achieve, but when the selection of one combo is changed, you need to set the datasource of all other child combos to nothing (except for the immediate child which you will rebind).

Unless your database is massive, you could load everything into datatables then create a dataview and set the rowfilters - then bind the dataviews to the combos.

[Shuja Ali]

@gini2
Please avoid posting same question in different threads. I have merged the two threads.

[__gini2]

Thank You so much for your feedback, I understand what you have answered, but could you provide me with an algorithm or coding so that I can better understand what you mean

[Shuja Ali]

You will have to write your own code. Following are the steps:

1. Handle the Parent Combo Box's SelectedIndexChange Event.
2. In the event handler, get all the values from the database for the Child Combo Box using the selected item of the parent combo box as the criteria.
3. Bind / Load the values in to the child combo box.