blocks|key|1871162|text|这很简单。该函数未运行。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1871163|Javascript是严格意义上的单线程。如果浏览器正在响应任何用户事件，则当前没有任何函数正在运行。|1871164|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

That's very easy. The function is not running.

Javascript is strictly single threaded. If the browser is responding to any user events, there is no function currently running.

blocks|key|854780|text|设置外部标志。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|854781|var+functionIsRunning+=+false;

function+myFunction()+{
++++if+(!functionIsRunning)+{
++++++++functionIsRunning+=+true;
++++++++//do+stuff
++++++++functionIsRunning+=+false;
++++}
}|code-block|syntax|javascript|854782|同样的原理也适用于jQuery函数。|854783|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Set an external flag.

<pre><code>var functionIsRunning = false;

function myFunction() {
 if (!functionIsRunning) {
 functionIsRunning = true;
 //do stuff
 functionIsRunning = false;
 }
}
</code></pre>

The same principle applies to jQuery functions.

blocks|key|5284649|text|如果您调用了很多函数，那么有很多实用程序可以帮助您管理这个签出承诺|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5284650|http://api.jquery.com/promise/|offset|length|5284651|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|U|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

If your calling alot of functions there are plenty of utilities to help you manage this check out Promise

<a href="http://api.jquery.com/promise/" rel="nofollow">http://api.jquery.com/promise/</a>

blocks|key|854161|text|你可以设置一个标志。如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|854162|(function+()+{

++++//+your+application+within+a+closure+to+not+pollute+global+scope
++++var+handlerRunning+=+false;
++++//+the+function+that+will+be+called+and+shouldn't+be+running+twice
++++var+handler+=+function+()+{
++++++++if+(handlerRunning)+return;
++++++++handlerRunning+=+true;
++++++++//+do+stuff+here
++++++++//+when+you're+done,+set+handlerRunning+to+false
++++++++handlerRunning+=+false;
++++}

++++//+assign+your+code+to+event+handler+for+example
++++document.getElementById('awesome-button').addEventListener('click',+handler,+false);

}());|code-block|syntax|javascript|854163|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You could set a flag. Something like this:

<pre><code>(function () {

 // your application within a closure to not pollute global scope
 var handlerRunning = false;
 // the function that will be called and shouldn't be running twice
 var handler = function () {
 if (handlerRunning) return;
 handlerRunning = true;
 // do stuff here
 // when you're done, set handlerRunning to false
 handlerRunning = false;
 }

 // assign your code to event handler for example
 document.getElementById('awesome-button').addEventListener('click', handler, false);

}());
</code></pre>

blocks|key|5284706|text|没有，但你可以使用一个变量来设置一个函数是否被执行。类似于：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|5284707|function+MyWrapper()+{++++
++++this.running+=+false;
++++this.run+=+function()+{
++++++++if+(this.running==false)+{
++++++++++++this.running+=+true;
++++++++++++//+do+something
++++++++++++this.running+=+false;
++++++++++++return+true;
++++++++}
++++++++else+{
++++++++++return+false;
++++++++}
++++};
}|code-block|syntax|javascript|5284708|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

No off the top of my head, but you could use a variable to set whether a function being executed. something like :

<pre><code>function MyWrapper() { 
 this.running = false;
 this.run = function() {
 if (this.running==false) {
 this.running = true;
 // do something
 this.running = false;
 return true;
 }
 else {
 return false;
 }
 };
}
</code></pre>

blocks|key|1245823|text|使用jQuery.when()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1245824|1245825|如果将单个延迟传递给jQuery.when，则该方法将返回其Promise对象(延迟方法的子集)。可以调用Promise对象的其他方法来附加回调，如deferred.then。当延迟被解析或拒绝时，通常由最初创建延迟的代码执行，相应的回调将被调用。例如，jQuery.ajax()返回的jqXHR对象是一个Promise，可以这样使用：|blockquote|1245826|1245827|1245828|$.when(+$.ajax(+"test.aspx"+)+).then(function(+data,+textStatus,+jqXHR+)+{
+++alert(+jqXHR.status+);+//+Alerts+200
});|code-block|syntax|javascript|1245829|entityMap|0|LINK|mutability|MUTABLE|url|http://api.jquery.com/jQuery.when/|1|http://api.jquery.com/deferred.then/^0|2|D|2|D|0|0|0|A|B|22|D|3J|D|22|D|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]]|E|$]]|$1|F|3|-4|5|6|7|16|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@$9|1E|A|1F|1|1G]]|E|$]]|$1|J|3|-4|5|6|7|1H|8|@]|D|@]|E|$]]|$1|K|3|-4|5|6|7|1I|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|1J|8|@]|D|@]|E|$O|P]]|$1|Q|3|-4|5|6|7|1K|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]|Y|$5|T|U|V|E|$W|Z]]]]

use <a href="http://api.jquery.com/jQuery.when/" rel="nofollow"><code>jQuery.when()</code></a>

<blockquote>
 If a single Deferred is passed to <code>jQuery.when</code>, its Promise object (a subset of the Deferred methods) is returned by the method. Additional methods of the Promise object can be called to attach callbacks, such as <a href="http://api.jquery.com/deferred.then/" rel="nofollow"><code>deferred.then</code></a>. When the Deferred is resolved or rejected, usually by the code that created the Deferred originally, the appropriate callbacks will be called. For example, the jqXHR object returned by <code>jQuery.ajax()</code> is a Promise and can be used this way:
</blockquote>

<pre><code>$.when( $.ajax( "test.aspx" ) ).then(function( data, textStatus, jqXHR ) {
 alert( jqXHR.status ); // Alerts 200
});
</code></pre>

blocks|key|5284777|text|回复晚了，但我还是想在这里注册我的答案。我遇到了一个类似的问题，我有一个嵌入了setInterval的后台服务器检查功能。但是，在我的代码中也有很多可能在其他条件下触发相同的函数。因此，为了确保不会调用它，我简单地使用了本地存储来确保函数不会一次又一次地被调用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|5284778|这个函数在我的HTML文件中，|5284779|function+serverCheck(value){
+++localStorage.setItem("isFunctionRunning",1);+
+++setInterval(checkServerStatus,+value);
}+|code-block|syntax|javascript|5284780|下面的代码片段在我的另一个JS文件中，|5284781|function+xyz(){
+++//someCode
+++var+checkFunction+=+localStorage.getItem("isFunctionRunning");
+++if(checkFunction+!=+1){
++++++serverCheck(frequency);
+++}
}|5284782|entityMap^0|13|B|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|W|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

A late reply, but still I wanted to register my answer here.
I encountered a similar issue where I've a background server check function with <code>setInterval</code> embedded in it. But, there are also a lot of possibilities in my code to trigger the same function on some other criteria. So, to make sure I'm not recalling it, I simply used local storage to ensure the function is not called again and again.

This function is in my HTML file,

<pre><code>function serverCheck(value){
 localStorage.setItem("isFunctionRunning",1); 
 setInterval(checkServerStatus, value);
} 
</code></pre>

The below snippet is in my another JS file,

<pre><code>function xyz(){
 //someCode
 var checkFunction = localStorage.getItem("isFunctionRunning");
 if(checkFunction != 1){
 serverCheck(frequency);
 }
}
</code></pre>

I have a document that may give the user the ability to run the same function more than once. Is there a way to check if the function is currently running before I can reactivate it again?

Is there a way to check if a function is currently running in jQuery?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个文档，可以让用户多次运行相同的函数。有没有办法在重新激活函数之前检查函数当前是否正在运行？

问有没有一种方法可以检查函数当前是否在jQuery中运行？
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问有没有一种方法可以检查函数当前是否在jQuery中运行？EN