转载---VB DorpDownList控件 添加选项

参考博客：https://blog.csdn.net/hejingyuan6/article/details/16847119

第一种：使用<asp:ListItem>方法

<asp:DropDownList id="weste" runat="server">
          <asp:ListItem Value="0">小学</asp:ListItem>
          <asp:ListItem Value="1">中学</asp:ListItem>
          <asp:ListItem Value="2">大学</asp:ListItem>
</asp:DropDownList>

第二种：使用Items属性的Add方法（mysql数据 作为 数据源）

通用方法：
#Region "给下拉列表设置数据源"
        Public Shared Sub setBindDropListDataSourseNew(ByVal dt As DataTable, ByVal ddlDropList As ExDropDownList, ByVal value As String, ByVal name As String)
            If ddlDropList.Items.Count > 0 Then
                ddlDropList.Items.Clear()
            End If
            If Not dt Is Nothing Then
                ddlDropList.Items.Add(New ListItem("", ""))
                For i As Integer = 0 To dt.Rows.Count - 1
                    ddlDropList.Items.Add(New ListItem(dt.Rows(i)(name), dt.Rows(i)(value)))
                Next
            End If
        End Sub
#End Region

方法setBindDropListDataSourseNew(ByVal dt As DataTable, ByVal ddlDropList As ExDropDownList, ByVal value As String, ByVal name As String)
参数1：绑定的数据源 datatable类型
参数2：给哪个控件绑定，控件Id
参数3：下拉列表的value值，对应数据库的列名 classno
参数4：下拉列表的text值，对应数据库的列名  classname
ASP代码：

<asp:DropDownList ID="ddl_class1" runat="server" IsEnterToTab="true"  OnSelectedIndexChanged="ddl_class1_SelectedIndexChanged" AutoPostBack="true">
</asp:DropDownList>

<asp:DropDownList ID="ddl_class2" runat="server" IsEnterToTab="true"   AutoPostBack="true">
</asp:DropDownList>

 VB代码：

Protected Sub ddl_class1_SelectedIndexChanged(sender As Object, e As EventArgs)
        Utils.Util.setBindDropListDataSourseNew(dbaComm.getClass2(ddl_class1.SelectedValue), ddl_class2, "class2", "classname")
End Sub

Public Class DBACommFnc
    Public Shared dbaComm As New DBACommFnc
#Region "查询分类"
    Public Function getClass2(ByVal class1 As String) As DataTable
        Dim p_cmd As String = "SELECT m14.`class2`,m14.`classname` FROM  m14 WHERE 1 = 1 AND m14.`class1` = '" & class1 & "' AND m14.`class2` <> '000'AND m14.`class3` = '000';"
        Dim dt As DataTable = dba.fncSelect(p_cmd)
        Return dt
    End Function
#End Region