这里是角度控制器中的基本代码：
$scope.runAsync = function() {
var asyncFn1 = function(data){
var deferred = $q.defer();
$timeout(function(){
console.log("Async fn1 " + data);
$scope.outputLines.push("Async fn1 " + data);
deferred.resolve("Async fn1 " + data);
},1000);
return deferred.promise;
}
var asyncFn2 = function(data){
var deferred = $q.defer();
$timeout(function(){
console.log("Async fn2 " + data);
$scope.outputLines.push("Async fn2 " + data);
deferred.resolve("Async fn2 " + data);
},1000);
return deferred.promise;
}
asyncFn1(1)
.then(function(data){asyncFn2(data)})
.then(function(data){asyncFn2(data)})
.then(function(data){asyncFn2(data)});
}
当我运行这个我得到以下输出：
Async fn1 1 Async fn2 Async fn1 1 Async fn2 undefined Async fn2 undefined
我如何将它们链接在一起，使第三个调用获得第二个调用的结果，第四个调用获得第三个调用的结果？
我创建了一个jsFiddle：http://jsfiddle.net/rhDyL/
then(successCallback,errorCallback) – regardless of when the promise
was or will be resolved or rejected calls one of the success or error
callbacks asynchronously as soon as the result is available. The
callbacks are called with a single argument the result or rejection
reason.This method returns a new promise which is resolved or rejected via
the return value of the successCallback or errorCallback.
对于successCallack或errorCallback的返回值，根据Domenic’s slides：
if the return value is a promise then the promise adopts the returned
promise’s state otherwise the success callback is immediately called
with the return value
根据定义，您的代码缺少return关键字。应该如下：
asyncFn1(1)
.then(function(data){return asyncFn2(data)})
.then(function(data){return asyncFn2(data)})
.then(function(data){return asyncFn2(data)});
