Question

我有一个带有多个UpdatePanel的ASP.NET Web表单，我希望有一个计时器只触发其中一个UpdatePanel来更新。然后，我想要一个单独的UpdatePanel来更新DropDownList的OnSelectedIndexChanged事件。我的代码将更新定时器触发的面板，但是当我更改索引时，下拉触发的面板将等到下一个计时器滴答更新。如何立即更新下拉触发的面板？代码如下。

C＃：

public partial class WebForm2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void Timer1_Tick(object sender, EventArgs e)
    {
        Label1.Text = "UpdatePanel1 refreshed at: " +
      DateTime.Now.ToLongTimeString();

    }

    protected void dropDown_indexChange(object sender, EventArgs e)
    {
        Label2.Text = "UpdatePanel2 refreshed at: " +
          DateTime.Now.ToLongTimeString();
        //UpdatePanel2.Update(); -- Didn't help
    }
}

ASP：

<form id="form1" runat="server">
<div>
    <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
    <br />
    <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <asp:Label ID="Label1" runat="server" Text="not updated yet"></asp:Label>
            <asp:Timer ID="Timer1" runat="server" Interval="3000" ontick="Timer1_Tick"></asp:Timer>
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />
        </Triggers>
    </asp:UpdatePanel>
    <br />
    <asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <asp:Label ID="Label2" runat="server" Text="also not updated yet"></asp:Label>
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="DropDownList1"  EventName="SelectedIndexChanged" />
        </Triggers>
    </asp:UpdatePanel>
    <br />
    <br />
    <asp:DropDownList OnSelectedIndexChanged="dropDown_indexChange" ID="DropDownList1" runat="server">
        <asp:ListItem>This</asp:ListItem>
        <asp:ListItem>That</asp:ListItem>
        <asp:ListItem>The Other</asp:ListItem>
    </asp:DropDownList>
</div>
</form>

Answer 1

将DropDownList移动到UpdatePanel并在其上设置.AutoPostBack = true。

UpdatePanel Timer会导致所有面板更新

1 个答案: