How to show alert from code behind after page loads completely?

Question

I am showing alert at button click and have tab control at page . Alert appears but tab disappears at alert. I want to show alert so that tab will not disappear at alert. Is there any technique how to handle this thing ?

<asp:TabContainer ID="TabContainer1" runat="server" ActiveTabIndex="0">
<asp:TabPanel ID="pael1" HeaderText="IP text" runat="server">
<ContentTemplate>

</ContentTemplate>
</asp:TabPanel>
<asp:TabPanel ID="panel2" HeaderText="text" runat="server">  
    <ContentTemplate>
       // Button Click Event
    </ContentTemplate>
     </asp:TabPanel>
</asp:TabContainer>

protected _Click(object sender, EventArgs e)
        {
           ScriptManager.RegisterStartupScript(this.Page, Page.GetType(), "Message", "alert('Connection Successful!')", true);
        }

Answer 1

您可以使用：

ClientScript.RegisterStartupScript(Page.GetType(), "mykey", "alert('"+ ex.Message +"');", true);

Answer 2

First of all, you should be using the following command according to the MSDN website ( http://msdn.microsoft.com/en-us/library/asz8zsxy(v=vs.110).aspx ):

Note: the script should be within <script></script> .

ScriptManager.RegisterStartupScript(this.Page, Page.GetType(), "Message", "<script type=text/javascript>alert('Connection Successful!');</script>", true);

The script is added to the top of your page, before the content, so the alert is displayed before your page is rendered. In order to fix this issue, use:

ScriptManager.RegisterStartupScript(this.Page, Page.GetType(), "Message", "<script type=text/javascript>window.onload = function(){alert('Connection Successful!');}</script>", true);

By doing so, you ensure that only when the page (JavaScript window object) loads the alert is displayed.

If you are using jquery, you can also use:

ScriptManager.RegisterStartupScript(this.Page, Page.GetType(), "Message", "<script type=text/javascript>$(window).load(function() {alert('Connection Successful!');});</script>", true);