[RESOLVED] How to fill a combo box at Run time

[tvb2727]

How do I fill a combo box at run time and set the selected value as well? I'm filling the the combo box from a database.

[riteshjain1982]

please show us how your are fetching Records from database..

[jmcilhinney]

Populate a DataTable and assign it to the DataSource property. Set the DisplayMember and ValueMember properties to the names of the column you want to display and the primary key column respectively. To select an item you would most likely either set the SelectedIndex to the index of the row you want to select or else set the SelectedValue to the ID of the row you want to select.

[tvb2727]

The code is below. I want to put the year in the combo box for the user to select and then the database name to go in the selected value position.

  Private Sub load_year_combobox()
        Try : Dim SQLdtr2 As Data.OleDb.OleDbDataReader : Dim SQLcmd As Data.OleDb.OleDbCommand
            Dim sql_select As String = "" : Dim timer_integer As Integer = 0 : Dim timer_count As Integer = 0
            sql_select = "SELECT db_name, year_id " + _
                "FROM tbl_past ORDER BY ID"
            SQLcmd = New Data.OleDb.OleDbCommand(sql_select, mainconnection)
            mainconnection.Open() : SQLdtr2 = SQLcmd.ExecuteReader
            cmbYear.Items.Clear() : cmbYear.Items.Add("Select Year to Search")
            Do : While SQLdtr2.Read()
                    cmbYear.Items.Add(SQLdtr2(1))
                    'SQLdtr2(0) 
                End While
            Loop While SQLdtr2.NextResult : mainconnection.Close()
        Catch ex As Exception
            MsgBox(ex.ToString) : m.errors(show_error, ex.ToString, error_l)
        End Try
    End Sub

[riteshjain1982]

as suggested by JMC you can fill the Datatable using OleDbDataAdapter and bind it with your comobox like:

cmbYear.DataSource = dtYear
cmbYear.DisplayMemeber = "db_name"
cmbYear.ValueMember = "year_id"

[tvb2727]

I would like to connect it with the way I posted earlier instead of connecting it to the data source. The reason is because I might read this data via a stream reader instead of the database. So how can I set the selected value with the code I posted?

[riteshjain1982]

I would like to connect it with the way I posted earlier instead of connecting it to the data source. The reason is because I might read this data via a stream reader instead of the database. So how can I set the selected value with the code I posted?

Not sure why cant you use DataTable even if you are fetching data from StreamReader?

anyway the alternative could be:

Private Sub load_year_combobox()
        Try : Dim SQLdtr2 As Data.OleDb.OleDbDataReader : Dim SQLcmd As Data.OleDb.OleDbCommand
Dim arrYear As New ArrayList
            Dim sql_select As String = "" : Dim timer_integer As Integer = 0 : Dim timer_count As Integer = 0
            sql_select = "SELECT db_name, year_id " + _
                "FROM tbl_past ORDER BY ID"
            SQLcmd = New Data.OleDb.OleDbCommand(sql_select, mainconnection)
            mainconnection.Open() : SQLdtr2 = SQLcmd.ExecuteReader
            
            Do : While SQLdtr2.Read()
                    arrYear.Add(New ComboBoxItem(SQLdtr2 ("year_id"), SQLdtr2 "db_name"))               
 End While
            Loop While SQLdtr2.NextResult : mainconnection.Close()
cmbYear.DataSource = arrYear
cmbYear.DisplayMemeber = "db_name"
cmbYear.ValueMember = "year_id"
        Catch ex As Exception
            MsgBox(ex.ToString) : m.errors(show_error, ex.ToString, error_l)
        End Try
    End Sub

[jmcilhinney]

I would like to connect it with the way I posted earlier instead of connecting it to the data source. The reason is because I might read this data via a stream reader instead of the database. So how can I set the selected value with the code I posted?

That's not a valid reason. It doesn't matter where the data comes from. Just put it into a list - any list - and bind that list to the control as suggested. The list can be a DataTable, array, List(Of T) or any other object that implements the IList or IListSource interface.

[tvb2727]

This is what I want to do:

    cmbYear.Items.Add(New comboboxitem(SQLdtr2(1), SQLdtr2(0)))

but I have the error:

Error 1 Type 'comboboxitem' is not defined.

[tvb2727]

That's not a valid reason. It doesn't matter where the data comes from. Just put it into a list - any list - and bind that list to the control as suggested. The list can be a DataTable, array, List(Of T) or any other object that implements the IList or IListSource interface.

I've just never done much with data tables.

[riteshjain1982]

Forgot to add ComboboxItem Class

Public Class ComboBoxItem

Private piyear_id As String

Private pidb_name As String

Public Sub New(ByVal stryearid As String, ByVal strdbname As String)

piyear_id = stryearid 

pidb_name = strdbName

End Sub

Public Property year_id() As String

Get

Return piyear_id 

End Get

Set(ByVal value As String)

piyear_id = value

End Set

End Property

Public Property db_name() As String

Get

Return pidb_name 

End Get

Set(ByVal value As String)

pidb_name = value

End Set

End Property

 

End Class

[tvb2727]

Thanks riteshjain1982. This is what I needed.