Imports System.Data.SqlClient
Public Class Form12
Public pbs As New BindingSource
Public cbs As New BindingSource
Private Sub Form12_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim con As New SqlConnection(“data source=san\sqlexpress;initial catalog=northwind;integrated security=true;”)
Dim da1 As New SqlDataAdapter(“select * from categories”, con)
Dim da2 As New SqlDataAdapter(“select * from products”, con)
Dim ds As New DataSet
da1.Fill(ds, “cat”)
da2.Fill(ds, “pro”)
Dim r As DataRelation
r = New DataRelation(“cp”, ds.Tables(“cat”).Columns(“categoryid”), ds.Tables(“pro”).Columns(“categoryid”))
ds.Relations.Add(r)
pbs.DataSource = ds
pbs.DataMember = “cat”
cbs.DataSource = pbs
cbs.DataMember = “cp”
ComboBox1.DataSource = pbs
ComboBox1.DisplayMember = “categoryname”
ComboBox1.ValueMember = “categoryid”
DataGridView1.DataSource = cbs
End Sub
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
If Not ComboBox1.SelectedIndex = -1 Then
Dim drv As DataRowView = pbs.Item(ComboBox1.SelectedIndex)
Dim b() As Byte
b = drv.Item(“picture”)
Dim ms As New System.IO.MemoryStream
ms.Write(b, 78, b.Length – 78)
Dim bmp As New Bitmap(ms)
PictureBox1.Image = bmp
End If
End Sub
End Class
