在gridview中访问下拉列表（选定值）

Question

我在获取我们在 aspx Gridview 和其中的下拉列表中拥有的下拉列表选择值时遇到了一些麻烦：

<asp:GridView ID="grid1" runat="server" autogeneratecolumns="true" >
    <Columns>
        <asp:BoundField HeaderText="something" />
        <asp:TemplateField HeaderText="filtras">
            <HeaderTemplate>
                <asp:DropDownList ID="dropdown1" runat="server"
                    OnLoad="dropdownLoad"
                    OnSelectedIndexChanged="updatetable" />
            </HeaderTemplate>
         </asp:TemplateField>
    </Columns>
</asp:GridView>

我们使用OnLoad 事件为DropDownList 填充值，然后当我们从DropDownList 中选择某些内容时，OnSelectedIndexChange 事件应该允许我们获取选定的值并使用它做我们想做的事情（在这种情况下过滤网格），但 OnSelectedIndexChange 永远不会被执行。

protected void Page_Load(object sender, EventArgs e)
{ 
    //Create Gridview + fill with values
    if (IsPostBack)
    {
        return;
    }

    ArrayList mycountries = new ArrayList();
    mycountries.Add("Norway");
    mycountries.Add("Sweden");
    mycountries.Add("France");
    mycountries.Add("Italy");
    mycountries.TrimToSize();
    mycountries.Sort();

    rb.DataSource = mycountries;
    rb.DataBind();

    grid1.DataSource = mycountries;
    grid1.DataBind();
}

protected void dropdownLoad(object sender, EventArgs e)
{   // fill dropDownList in GridView with data
    DropDownList dropdown = sender as DropDownList;
    if (dropdown != null)
    {
        ArrayList mycountries = new ArrayList();
        mycountries.Add("Norway");
        mycountries.Add("Sweden");
        mycountries.Add("France");
        mycountries.Add("Italy");
        mycountries.TrimToSize();
        mycountries.Sort();

        dropdown.DataSource = mycountries;
        dropdown.DataBind();

        TextBox1.Text = dropdown.SelectedIndex.ToString();
    }
}

protected void updatetable(object sender, EventArgs e)
{// after dropDownList element was selected change dropdownlist values/or filter the table...
 //this part is never executed ! Why?

    DropDownList dropdown = sender as DropDownList;
    if (dropdown != null)
    {
        ArrayList mycountries = new ArrayList();
        mycountries.Add("UK");
        mycountries.Add("USA");
        mycountries.Add("Sweden");
        mycountries.Add("Hungary");
        mycountries.TrimToSize();
        mycountries.Sort();

        dropdown.DataSource = mycountries;
        dropdown.DataBind();
    }
}

如何获取DropDownList 的选定值？我的调试器显示 OnSelectedIndexChange 永远不会执行。 我尝试按照这个问题Setting selectedvalue for a dropdownlist in GridView 中的建议进行操作，但没有奏效。

Answer 1

您是否尝试过将下拉控件的 AutoPostBack 设置为 true 以导致回发？