Public Class Form1
Dim con As New OleDb.OleDbConnection("provider=microsoft.ace.oledb.12.0;data source=db.accdb")
Dim dt As DataTable
Dim da As OleDb.OleDbDataAdapter
Dim cm As OleDb.OleDbCommandBuilder
Private Sub gd()
dt = New DataTable
da = New OleDb.OleDbDataAdapter("select * from tb where countryid=0", con)
cm = New OleDb.OleDbCommandBuilder(da)
da.Fill(dt)
countries.DataSource = dt
countries.DisplayMember = "countryorcity"
End Sub
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
gd()
End Sub
Private Sub countries_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles countries.SelectedIndexChanged
If dt.Rows.Count <= 0 Then Exit Sub
If countries.Items.Count <= 0 Then Exit Sub
Dim dt2 As New DataTable
Dim da2 As New OleDb.OleDbDataAdapter("select * from tb where countryid=" & dt.Rows(countries.SelectedIndex)(0), con)
da2.Fill(dt2)
cities.DataSource = dt2
cities.DisplayMember = "countryorcity"
End Sub
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
Dim a As String = InputBox("أكتب اسم دولة")
If a.ToString.Trim = "" Then Return
Dim row As DataRow = dt.NewRow
row(1) = a
row(2) = 0
dt.Rows.Add(row)
da.Update(dt)
countries.Refresh()
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim a As String = InputBox("أكتب اسم مدينة")
If a.ToString.Trim = "" Then Return
Dim row As DataRow = dt.NewRow
row(1) = a
row(2) = dt.Rows(countries.SelectedIndex)(0)
dt.Rows.Add(row)
da.Update(dt)
gd()
cities.Refresh()
End Sub
End Class
