怎么在服务器端获得联动DROPDOWNLIST的值

ghgjjjj

我的联运菜单是通过数据库提取的值．


正常dropdownlist  

textbox.SelectedItem.Value

clssmlove

VB是这样用  其他语言也是一样
Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles  DropDownList1.SelectedIndexChanged
        dim a as string = BlockDropDownList.SelectedValue

End Sub

ghgjjjj

要在dropdownlist中写事件吗