AngularJS：顺序承诺链

【问题标题】：AngularJS : Seqential Promise chainAngularJS：顺序承诺链
【发布时间】：2026-01-12 12:30:02
【问题描述】：

函数one 将值传递给two，然后two 将值传递给three。这些函数中的任何一个都可能需要任何时间来返回数据。我怎样才能让他们等待价值，而不是冲过去打印undefined。

var deferred = $q.defer();

var one = function (msg) {
  $timeout(function () {
    console.log(msg);
    return "pass this to two";
  }, 2000);
};

var two = function (msg) {
  console.log(msg);
  return "pass this to three";
};

var three = function (msg) {
  console.log(msg);
};

deferred.promise
  .then(one)
  .then(two)
  .then(three);

deferred.resolve("pass this to one");

【问题讨论】：

标签： javascript angularjs promise angular-promise

【解决方案1】：

您需要return 来自每个执行异步操作的函数的承诺。

在您的情况下，您的 one 函数返回 undefined，而它需要在超时后返回您为 "pass this to two" 值创建的承诺：

function one (msg) {
  return $timeout(function () {
//^^^^^^
    console.log(msg);
    return "pass this to two";
  }, 2000);
}

顺便说一句，链不是使用var deferred = $q.defer();，最好写成：

one("pass this to one")
  .then(two)
  .then(three);

【讨论】：