防止在单击按钮时刷新页面

Question

我也尝试了按钮和更新面板中的几乎所有设置，但 当我单击按钮时，它仍然刷新整个页面。

<form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server"> 
    </asp:ScriptManager>

    <div class="auto-style1" style="background-image: none; background-color: #C0C0C0;">

        <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
            <ContentTemplate>
                <asp:Label ID="Label2" runat="server" Text="1" Width="100px"></asp:Label>                  
                &nbsp;                  
                <asp:Button ID="Button2" runat="server" 
                    OnClick="Button2_Click" Text="Button" Height="26px" 
                    Width="56px" CausesValidation="False" />                    
                <br />                    
            </ContentTemplate>
            <Triggers>
                <asp:AsyncPostBackTrigger ControlID="Button2"  EventName="Click" />
            </Triggers>
        </asp:UpdatePanel>

    </div>
</form>    

下面是代码背后。单击按钮时，标签将添加1。

public partial class WebForm1 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {            
    }

    protected void Button2_Click(object sender, EventArgs e)
    {
        Label2.Text += "1";
    }
}