DropDownList在GridView中(vb.net)

曾有用户给Insus.NET留言，下拉式菜单DropDownList在GridView编辑选择。 http://www.cnblogs.com/insus/articles/1411016.html#2053183 ，需要vb.net版本，现在Insus.NET把主要部分的改写了一些，请参考：

xxx.aspx HTML程序： 

View Code <asp:GridView ID="GridView1" runat="server" SkinID="gridviewSkin" DataKeyNames="MediaId"
            AllowPaging="true" OnRowDataBound="GridView1_RowDataBound" OnRowCancelingEdit="GridView1_OnCancelCommand"
            OnRowEditing="GridView1_OnEditCommand" OnRowUpdating="GridView1_OnUpdateCommand">
            <AlternatingRowStyle BackColor="White" />
            <RowStyle BackColor="WhiteSmoke" />
            <Columns>
                <asp:TemplateField HeaderText="类别">
                    <HeaderStyle BorderColor="#c0c0c0" BorderWidth="1" Width="50px" />
                    <ItemStyle BorderColor="#c0c0c0" BorderWidth="1" Width="50px" />
                    <ItemTemplate>
                        <%# Eval("TypeName")%>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:DropDownList ID="ddlMediaType" runat="server">
                        </asp:DropDownList>
                    </EditItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="编辑">
                    <HeaderStyle BorderWidth="1" BorderColor="#c0c0c0" Width="30" />
                    <ItemStyle BorderWidth="1" BorderColor="#c0c0c0" />
                    <ItemTemplate>
                        <asp:ImageButton ID="imgBtnEdit" runat="server" CommandName="Edit" ImageAlign="absmiddle"
                            ImageUrl="~/Image/edit.gif" CausesValidation="false" />
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:ImageButton ID="imgBtnUpdate" runat="server" CommandName="Update" ImageAlign="absmiddle"
                            ImageUrl="~/Image/update.gif" ValidationGroup="vg_Edit" />
                        <asp:ImageButton ID="imgBtnCancel" runat="server" CommandName="Cancel" ImageAlign="absmiddle"
                            ImageUrl="~/Image/cancel.gif" CausesValidation="false" />
                    </EditItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>

xxx.aspx.vb代码，代码有中文注释： 

View Code Partial Class Management_DropDownListInGridViewDemo
    Inherits System.Web.UI.Page

    '数据源的对象
    Dim objMedia As New Media()
    'DropDownList数据源的对象
    Dim objMediaType As New MediaType()

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
            Data_Binding()
        End If
    End Sub

    '数据绑定,建议不要直接写在page_Load事件中
    Private Sub Data_Binding()
        '数据源绑定到GriwView
        Me.GridView1.DataSource = objMedia.GetMediaAllByIsActive(True)
        Me.GridView1.DataBind()
    End Sub

    '绑定GridView控件中的DropDownlist
    Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
        '下面这个类别，请参考Insus.NET的博客http://www.cnblogs.com/insus/articles/1399645.html
        Dim objListControlUtility As New ListControlUtility()
        If e.Row.RowType = DataControlRowType.DataRow Then
            '记得要写下面这个判断，如果找不到GridView中的DropDownList会发生程序运行异常
            If e.Row.FindControl("ddlMediaType") IsNot Nothing Then
                '找到GridView的DorpDownList的对象并转DorpDownList为控件
                Dim ddl As DropDownList = CType(e.Row.FindControl("ddlMediaType"), DropDownList)
                '对DropDownList数据源绑定
                objListControlUtility.DropDownListParse(ddl, objMediaType.GetMediaTypeByIsActive(), "TypeName", "MediaTypeId", DataBinder.Eval(e.Row.DataItem, "MediaTypeId").ToString(), "--请选择--")
            End If
        End If
    End Sub

    Protected Sub GridView1_OnEditCommand(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
        '编辑记录，让程式知道是编辑哪一行。
        GridView1.EditIndex = e.NewEditIndex
        '绑定数据
        Data_Binding()
    End Sub

    Protected Sub GridView1_OnCancelCommand(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
        'Cancel编辑，回到数据绑定状态
        GridView1.EditIndex = -1
        '绑定数据
        Data_Binding()
    End Sub

    Protected Sub GridView1_OnUpdateCommand(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
        '找到记录的主键
        Dim pk As String = GridView1.DataKeys(e.RowIndex).Value.ToString()
        '找到DropDownList的选择的值
        Dim mediaTypeId As String = CType(GridView1.Rows(e.RowIndex).FindControl("ddlMediaType"), DropDownList).SelectedItem.Value

        '下面是其它字段或更新处理事件。
    End Sub

End Class