求高手帮我改段代码,谢谢!
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
myconn.Open()
Dim myds1 As New DataSet
Dim myda1 As New SqlDataAdapter("select distinct 汽车品牌 from 表1", myconn)
myda1.Fill(myds1, "表1")
ComboBox1.DataSource = myds1.Tables("表1")
ComboBox1.DisplayMember = "汽车品牌"
ComboBox1.Text = ""
myconn.Close()
End Sub
Private Sub ComboBox1_SelectedValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedValueChanged
Dim mysql As String = "select 发动机排量 from 表1 where 汽车品牌=@abc"
Dim myda As SqlDataAdapter = New SqlDataAdapter
Dim mycmd As SqlCommand = New SqlCommand(mysql, myconn)
myda.SelectCommand = mycmd
mycmd.Parameters.Add("@abc", SqlDbType.VarChar, 10).Value = ComboBox1.Text
Dim myds As New DataSet
myda.Fill(myds, "表1")
ComboBox2.DataSource = myds.Tables("表1")
ComboBox2.DisplayMember = "发动机排量"
myconn.Close()
End Sub