在回发之前停止用户离开 [英] Stop User Leaving Before Postback

问题描述

我在回发上运行了多个功能，这些功能可能需要一些时间才能完成.

启动回发后，我将显示带有以下代码的加载图像:

I have several functions running on a postback that can take a little time to complete.

When postback is initiated I show a loading image with this code:

function showLoader()
{
    document.getElementById("<%=loadingImage.ClientID%>").style.visibility="visible";
}

我希望能够向此功能添加代码，因此，如果用户此时尝试离开，则会通知他们操作尚未完成.

我找到了以下代码:

I want to be able to add code to this function so if user tries to leave at this point they are informed the operation is not complete.

I found this code:

function goodbye(e) {
    if(!e) e = window.event;
    //e.cancelBubble is supported by IE - this will kill the bubbling process.
    e.cancelBubble = true;
    e.returnValue = 'You sure you want to leave?'; //This is displayed on the dialog
    //e.stopPropagation works in Firefox.
    if (e.stopPropagation) {
        e.stopPropagation();
        e.preventDefault();
    }
}
window.onbeforeunload=goodbye;

这可行，但是我只希望代码在加载图像处于活动状态时处于活动状态.

我尝试了以下操作，但是当页面最终发回时，它会显示警告消息:

This works but I only want the code to be active when the loading image is active.

I tried the following but it shows the alert message when the page eventualy posts back:

function goodbye(e) {
    if(!e) e = window.event;
    //e.cancelBubble is supported by IE - this will kill the bubbling process.
    e.cancelBubble = true;
    e.returnValue = 'You sure you want to leave?'; //This is displayed on the dialog
    //e.stopPropagation works in Firefox.
    if (e.stopPropagation) {
        e.stopPropagation();
        e.preventDefault();
    }
}
function showLoader()
{
    document.getElementById("<%=loadingImage.ClientID%>").style.visibility="visible";
    window.onbeforeunload=goodbye;
}

有什么想法可以调整，使其仅在用户离开页面时显示，而在回发完成时不显示?

Any ideas how I can tweak this to just show when user leaves page and not when postback completes?

推荐答案

您知道您遇到的问题比用户还大离开.您的操作必须独立于用户状态.为什么?您不能阻止用户关闭浏览器！

You know you''ve got a bigger problem than the user leaving. Your operation has to be independant of the users state. Why? You cannot prevent the user from closing the browser!

这篇关于在回发之前停止用户离开的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！