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

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.

Checking the code

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?

Code:

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

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

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

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

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?

Code:

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

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

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.

Re: Checking the code

Quote:

Originally Posted by __gini2

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]

Re: Checking the code

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.

Re: Checking the code

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

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

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

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

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.