使用ajaxStop事件。

例如，假设你有一个载入…消息，同时获取100个ajax请求，你想隐藏该消息一旦加载。

jQuery文档:

$("#loading").ajaxStop(function() {
  $(this).hide();
});

请注意，它将等待所有ajax请求在该页面上完成。

正如其他答案所提到的，你可以使用ajaxStop()等待直到所有ajax请求完成。

$(document).ajaxStop(function() {
     // This function will be triggered every time any ajax request is requested and completed
});

如果你想为特定的ajax()请求做这件事，你能做的最好的是在特定的ajax请求中使用complete()方法:

$.ajax({
    type: "POST",
    url: "someUrl",
    success: function(data) {
        // This function will be triggered when ajax returns a 200 status code (success)
    },
    complete: function() {
        // This function will be triggered always, when ajax request is completed, even it fails/returns other status code
    },
    error: function() {
        // This will be triggered when ajax request fail.
    }
});

但是，如果你只需要等待几个和特定的ajax请求被完成?使用美妙的javascript承诺等待，直到这些ajax你想等待完成。我做了一个简单易读的示例，向您展示promises如何与ajax一起工作。请看下一个例子。我使用setTimeout来阐明这个示例。

// Note: // resolve() is used to mark the promise as resolved // reject() is used to mark the promise as rejected $(document).ready(function() { $("button").on("click", function() { var ajax1 = new Promise((resolve, reject) => { $.ajax({ type: "GET", url: "https://miro.medium.com/max/1200/0*UEtwA2ask7vQYW06.png", xhrFields: { responseType: 'blob'}, success: function(data) { setTimeout(function() { $('#image1').attr("src", window.URL.createObjectURL(data)); resolve(" Promise ajax1 resolved"); }, 1000); }, error: function() { reject(" Promise ajax1 rejected"); }, }); }); var ajax2 = new Promise((resolve, reject) => { $.ajax({ type: "GET", url: "https://cdn1.iconfinder.com/data/icons/social-media-vol-1-1/24/_github-512.png", xhrFields: { responseType: 'blob' }, success: function(data) { setTimeout(function() { $('#image2').attr("src", window.URL.createObjectURL(data)); resolve(" Promise ajax2 resolved"); }, 1500); }, error: function() { reject(" Promise ajax2 rejected"); }, }); }); var ajax3 = new Promise((resolve, reject) => { $.ajax({ type: "GET", url: "https://miro.medium.com/max/632/1*LUfpOf7teWvPdIPTBmYciA.png", xhrFields: { responseType: 'blob' }, success: function(data) { setTimeout(function() { $('#image3').attr("src", window.URL.createObjectURL(data)); resolve(" Promise ajax3 resolved"); }, 2000); }, error: function() { reject(" Promise ajax3 rejected"); }, }); }); Promise.all([ajax1, ajax2, ajax3]).then(values => { console.log("We waited until ajax ended: " + values); console.log("My few ajax ended, lets do some things!!") }, reason => { console.log("Promises failed: " + reason); }); // Or if you want wait for them individually do it like this // ajax1.then(values => { // console.log("Promise 1 resolved: " + values) // }, reason => { // console.log("Promise 1 failed: " + reason) // }); }); }); img { max-width: 200px; max-height: 100px; } <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <button>Make AJAX request</button> <div id="newContent"> <img id="image1" src=""> <img id="image2" src=""> <img id="image3" src=""> </div>

如果你需要简单的东西;Once and done回调

        //multiple ajax calls above
        var callback = function () {
            if ($.active !== 0) {
                setTimeout(callback, '500');
                return;
            }
            //whatever you need to do here
            //...
        };
        callback();

jQuery允许您指定是否希望ajax请求是异步的。您可以简单地使ajax请求同步，然后其余的代码直到它们返回才执行。

例如:

jQuery.ajax({ 
    async: false,
    //code
});

Javascript是基于事件的，所以你不应该等待，而应该设置钩子/回调

你可以只使用jquery.ajax的success/complete方法

或者你可以使用。ajaxcomplete:

$('.log').ajaxComplete(function(e, xhr, settings) {
  if (settings.url == 'ajax/test.html') {
    $(this).text('Triggered ajaxComplete handler.');
    //and you can do whatever other processing here, including calling another function...
  }
});

虽然你应该张贴一个伪代码你的(s) ajax请求(s)是(是)被调用更精确…

使用ajaxStop事件。

例如，假设你有一个载入…消息，同时获取100个ajax请求，你想隐藏该消息一旦加载。

jQuery文档:

$("#loading").ajaxStop(function() {
  $(this).hide();
});

请注意，它将等待所有ajax请求在该页面上完成。