我找到了一个简单的方法，使用shift()

function waitReq(id)
{
  jQuery.ajax(
  {
    type: 'POST',
    url: ajaxurl,
    data:
    {
      "page": id
    },
    success: function(resp)
    {
      ...........
      // check array length if not "0" continue to use next array value
      if(ids.length)
      {
        waitReq(ids.shift()); // 2
      )
    },
    error: function(resp)
    {
      ....................
      if(ids.length)
      {
        waitReq(ids.shift());
      )
    }
  });
}

var ids = [1, 2, 3, 4, 5];    
// shift() = delete first array value (then print)
waitReq(ids.shift()); // print 1

在@BBonifield回答的基础上，我写了一个实用函数，这样信号量逻辑就不会分布在所有ajax调用中。

untilAjax是一个实用函数，它在所有ajaxCalls完成后调用回调函数。

ajaxObjs是一个ajax设置对象的数组[http://api.jquery.com/jQuery.ajax/]。

Fn是回调函数

function untilAjax(ajaxObjs, fn) {
  if (!ajaxObjs || !fn) {
    return;
  }
  var ajaxCount = ajaxObjs.length,
    succ = null;

  for (var i = 0; i < ajaxObjs.length; i++) { //append logic to invoke callback function once all the ajax calls are completed, in success handler.
    succ = ajaxObjs[i]['success'];
    ajaxObjs[i]['success'] = function(data) { //modified success handler
      if (succ) {
        succ(data);
      }
      ajaxCount--;
      if (ajaxCount == 0) {
        fn(); //modify statement suitably if you want 'this' keyword to refer to another object
      }
    };
    $.ajax(ajaxObjs[i]); //make ajax call
    succ = null;
  };

示例:doSomething函数使用untilAjax。

function doSomething() {
  // variable declarations
  untilAjax([{
    url: 'url2',
    dataType: 'json',
    success: function(data) {
      //do something with success data
    }
  }, {
    url: 'url1',
    dataType: 'json',
    success: function(data) {
      //do something with success data
    }
  }, {
    url: 'url2',
    dataType: 'json',
    success: function(response) {
      //do something with success data
    }
  }], function() {
    // logic after all the calls are completed.
  });
}

注意:上面的答案使用的功能在编写这个答案时并不存在。我建议使用jQuery.when()而不是这些方法，但我把答案留给历史用途。

-

您可能可以使用一个简单的计数信号量，尽管如何实现它取决于您的代码。一个简单的例子是……

var semaphore  = 0,     // counting semaphore for ajax requests
    all_queued = false; // bool indicator to account for instances where the first request might finish before the second even starts

semaphore++;
$.get('ajax/test1.html', function(data) {
    semaphore--;
    if (all_queued && semaphore === 0) {
        // process your custom stuff here
    }
});

semaphore++;
$.get('ajax/test2.html', function(data) {
    semaphore--;
    if (all_queued && semaphore === 0) {
        // process your custom stuff here
    }
});

semaphore++;
$.get('ajax/test3.html', function(data) {
    semaphore--;
    if (all_queued && semaphore === 0) {
        // process your custom stuff here
    }
});

semaphore++;
$.get('ajax/test4.html', function(data) {
    semaphore--;
    if (all_queued && semaphore === 0) {
        // process your custom stuff here
    }
});

// now that all ajax requests are queued up, switch the bool to indicate it
all_queued = true;

如果你想让它像{async: false}一样操作，但又不想锁定浏览器，你可以用jQuery队列来完成同样的事情。

var $queue = $("<div/>");
$queue.queue(function(){
    $.get('ajax/test1.html', function(data) {
        $queue.dequeue();
    });
}).queue(function(){
    $.get('ajax/test2.html', function(data) {
        $queue.dequeue();
    });
}).queue(function(){
    $.get('ajax/test3.html', function(data) {
        $queue.dequeue();
    });
}).queue(function(){
    $.get('ajax/test4.html', function(data) {
        $queue.dequeue();
    });
});

如果从头开始，我强烈建议使用$.when()。

尽管这个问题有超过一百万个答案，但我仍然没有找到任何对我的情况有用的答案。假设您必须处理现有的代码库，已经进行了一些ajax调用，并且不想引入承诺的复杂性和/或重做整个事情。

我们可以很容易地利用jQuery的.data， .on和.trigger函数，这些函数一直是jQuery的一部分。

Codepen

我的解决方案的优点是:

显然回调依赖于什么 函数triggerNowOrOnLoaded并不关心数据是否已经加载或我们仍在等待它 将其插入现有代码非常容易

$(function() { // wait for posts to be loaded triggerNowOrOnLoaded("posts", function() { var $body = $("body"); var posts = $body.data("posts"); $body.append("<div>Posts: " + posts.length + "</div>"); }); // some ajax requests $.getJSON("https://jsonplaceholder.typicode.com/posts", function(data) { $("body").data("posts", data).trigger("posts"); }); // doesn't matter if the `triggerNowOrOnLoaded` is called after or before the actual requests $.getJSON("https://jsonplaceholder.typicode.com/users", function(data) { $("body").data("users", data).trigger("users"); }); // wait for both types triggerNowOrOnLoaded(["posts", "users"], function() { var $body = $("body"); var posts = $body.data("posts"); var users = $body.data("users"); $body.append("<div>Posts: " + posts.length + " and Users: " + users.length + "</div>"); }); // works even if everything has already loaded! setTimeout(function() { // triggers immediately since users have been already loaded triggerNowOrOnLoaded("users", function() { var $body = $("body"); var users = $body.data("users"); $body.append("<div>Delayed Users: " + users.length + "</div>"); }); }, 2000); // 2 seconds }); // helper function function triggerNowOrOnLoaded(types, callback) { types = $.isArray(types) ? types : [types]; var $body = $("body"); var waitForTypes = []; $.each(types, function(i, type) { if (typeof $body.data(type) === 'undefined') { waitForTypes.push(type); } }); var isDataReady = waitForTypes.length === 0; if (isDataReady) { callback(); return; } // wait for the last type and run this function again for the rest of the types var waitFor = waitForTypes.pop(); $body.on(waitFor, function() { // remove event handler - we only want the stuff triggered once $body.off(waitFor); triggerNowOrOnLoaded(waitForTypes, callback); }); } <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <body>Hi!</body>

美元。当不为我工作时，回调(x)而不是返回x工作如下所述:https://stackoverflow.com/a/13455253/10357604

看看我的解决方案:

1.将这个函数(和变量)插入到你的javascript文件:

var runFunctionQueue_callback;

function runFunctionQueue(f, index, callback) {

  var next_index = index + 1

  if (callback !== undefined) runFunctionQueue_callback = callback;

  if (f[next_index] !== undefined) {
    console.log(index + ' Next function avalaible -> ' + next_index);
    $.ajax({
      type: 'GET',
      url: f[index].file,
      data: (f[index].data),
      complete: function() {
        runFunctionQueue(f, next_index);
      }
    });
  } else {
    console.log(index + ' Last function');
    $.ajax({
      type: 'GET',
      url: f[index].file,
      data: (f[index].data),
      async: false,
      complete: runFunctionQueue_callback
    });
  }
}

2.用你的请求构建一个数组，像这样:

var f = [
           {file: 'file_path', data: {action: 'action', data: 'any_data}},
           {file: 'file_path', data: {action: 'action', data: 'any_data}},
           {file: 'file_path', data: {action: 'action', data: 'any_data}},
           {file: 'file_path', data: {action: 'action', data: 'any_data}}
        ];

3.创建回调函数:

function Function_callback() {
  alert('done');
}

4.使用参数调用runFunctionQueue函数:

runFunctionQueue(f, 0, QuestionInsert_callback);
// first parameter: array with requests data
// second parameter: start from first request
// third parameter: the callback function