使用 Javascript 在页面刷新时调用函数
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Call a function on page refresh using Javascript
提问by Rajat Shah
function warnuser()
{
return "Don't refresh the page.";
}
window.onbeforeunload = warnuser;
If the user refreshes the page and the user clicks 'leave this page' on confirmation box, i want to call a javascript function , otherwise not! I am confused about how to do that. Thank you
如果用户刷新页面并且用户在确认框中单击“离开此页面”，我想调用一个 javascript 函数，否则不会！我对如何做到这一点感到困惑。谢谢
采纳答案by ThiefMaster
You need to intercept the F5key press and setup the onbeforeunloadhandler only in that case:
只有在这种情况下，您才需要拦截F5按键并设置onbeforeunload处理程序：
document.addEventListener('keydown', function(e) {
if(e.which == 116) {
window.onbeforeunload = function() {
window.onbeforeunload = null;
return "Do you really want to refresh the page?";
}
}
}, false);
Demo: http://jsfiddle.net/ejDrq/
演示：http: //jsfiddle.net/ejDrq/
Note that this does not work if the user clicksthe Refresh button. It is impossible to intercept this.
请注意，如果用户单击“刷新”按钮，这将不起作用。这是不可能拦截的。
回答by Travis J
If you have control of the server side which is hosting the page then you can handle this logically with a semaphore(wiki:semaphore). Basically it is a spinning lock which would be implemented in their server side session. Resetting the page state if they have entered and not exited in a safe manner. Naturally, as with all spinning locks, there would have to be a safe state to clear the lock out.
如果您可以控制托管页面的服务器端，那么您可以使用semaphore( wiki:semaphore)逻辑处理此问题。基本上它是一个旋转锁，将在他们的服务器端会话中实现。如果他们已进入但未以安全方式退出，则重置页面状态。自然地，与所有旋转锁一样，必须有一个安全状态来清除锁。
