Win (Windows App) มีปัญหาเกี่ยวกับ combobox ค่ะ มาสามารถดึงข้อมูลจากฐานข้อมูลมาใส่เป็น option มันได้มั้ยคะ มันไม่ยอมขึ้นอ่าค่ะ

comboBox1.DataSource = DataItem
comboBox1.DisplayMember = "DisplayText"
comboBox1.ValueMember = "ValueText"

dim selectstr as string ="select * from tb_name"
dim cmd as new sqlcommand(selectstr,conn) '<---- conn คือ connectionstring
dim dr as sqldatareader
dr = cmd.excutereader

while dr.read
combobox1.items.add = dr("field_name")
end while

Public strSQL As String = "Provider=Microsoft.Jet.OleDb.4.0;Data Source= " & HttpContext.Current.Server.MapPath("~\App_Data\xxx.mdb")

bs.DataSource = ds
bs.DataMember = "Bank"

cbCustomer.DataSource = bs
cbCustomer.DisplayMember = "BankName"

Public Class Form4

    Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'BudgetDataSet1.Bank' table. You can move, or remove it, as needed.
        Dim sb As String = "SELECT BankID, BankName"
        sb &= vbCrLf & "FROM Bank"
        sb &= vbCrLf & "ORDER BY BankName"
        Dim stConn As String = "Data Source=.\SQLExpress;Initial Catalog=Test;User ID=sa;Password=xxxxxxx"
        Dim sqlCn As New SqlClient.SqlConnection(stConn)
        sqlCn.Open()
        Dim sqlCmd As New SqlClient.SqlCommand(sb, sqlCn)
        Dim da As New SqlClient.SqlDataAdapter(sqlCmd)
        da.Fill(Me.ds, "Bank")
        Me.bsBank.DataSource = Me.ds
        Me.bsBank.DataMember = "Bank"
        Me.z_BankName.DataSource = Me.bsBank
        Me.z_BankName.DisplayMember = "BankName"
    End Sub
End Class

 'combobox Customer
        Dim sqlCompany As String
        sqlCompany = "SELECT * FROM Clients"
        da = New OleDbDataAdapter(sqlCompany, Conn)
        da.Fill(ds, "Clients")
        bs.DataSource = ds
        bs.DataMember = "Clients"

        cbCustomer.DataSource = bs
        cbCustomer.DisplayMember = "CompanyName"
        cbCustomer.BeginUpdate()
        cbCustomer.ValueMember = "CompanyID"
        cbCustomer.EndUpdate()
        'cbCustomer.DataBindings.Add("Text", bs, "CompanyName")



        'combobox Agent
        Dim sqlAgent As String
        sqlAgent = "SELECT * FROM Agent"
        da = New OleDbDataAdapter(sqlAgent, Conn)
        da.Fill(ds, "Agent")
        bs.DataSource = ds
        bs.DataMember = "Agent"

        cbAgent.DataSource = bs
        cbAgent.DisplayMember = "Agent_name"
        'cbAgent.DataBindings.Add("Text", bs, "Agent_name")
        'cbCustomer.DataBindings.Add("Text", bs, "CompanyName")

        With cbAgent
            .BeginUpdate()
            .ValueMember = "Agent_ID"
            .EndUpdate()
        End With

 'combobox Customer
        Dim sqlCompany As String
        Dim bs As New BindingSource
        sqlCompany = "SELECT * FROM Clients"
        da = New OleDbDataAdapter(sqlCompany, Conn)
        da.Fill(ds, "Clients")
        bs.DataSource = ds
        bs.DataMember = "Clients"
        With cbCustomer
            .DataSource = bs
            .DisplayMember = "CompanyName"
            .BeginUpdate()
            .ValueMember = "CompanyID"
            .EndUpdate()
            '.DataBindings.Add("Text", bs, "CompanyName")
        End With



        'combobox Agent
        Dim sqlAgent As String
        Dim bs1 As BindingSource
        sqlAgent = "SELECT * FROM Agent"
        da = New OleDbDataAdapter(sqlAgent, Conn)
        'bs1.Fill(ds, "Agent")
        bs1.DataSource = ds
        bs1.DataMember = "Agent"


        cbAgent.DisplayMember = "Agent_name"
        'cbAgent.DataBindings.Add("Text", bs, "Agent_name")
        'cbCustomer.DataBindings.Add("Text", bs1, "CompanyName")

        With cbAgent
            .DataSource = bs1
            .BeginUpdate()
            .ValueMember = "Agent_ID"
            .EndUpdate()
        End With

da.Fill(ds, "Agent") 

       cbAgent.DisplayMember = "Agent_name"
       'cbAgent.DataBindings.Add("Text", bs, "Agent_name")
       'cbCustomer.DataBindings.Add("Text", bs1, "CompanyName")

       With cbAgent
           .DataSource = bs1
           .BeginUpdate()
           .ValueMember = "Agent_ID"
           .EndUpdate()
       End With

       With cbCustomer
           .DataSource = bs
           .DisplayMember = "CompanyName"
           .BeginUpdate()
           .ValueMember = "CompanyID"
           .EndUpdate()
           '.DataBindings.Add("Text", bs, "CompanyName")
       End With

Dim bs1 As BindingSource 

Dim bs1 As New BindingSource