RxJS：从 Observable.fromPromise 拆分数组结果

Question

我在这里使用 RxJS，我似乎无法克服这个看似简单的问题。

rx.Observable
    .from([1,2,3,54,3,22,323,23,11,2])
    .distinct()
    .subscribe(function next (x) {
        console.log('Next');
        console.log(x);
    }, function error (x) {
        console.log('Error');
        console.log(x);
    }, function completed () {
        console.log('Completed');
    });

上述代码按预期顺序吐出每个数组项。

rx.Observable
    .fromPromise(getNumbers([1,2,3,54,3,22,323,23,11,2]))
    .distinct()
    .subscribe(function next (x) {
        console.log('Next');
        console.log(x);
    }, function error (x) {
        console.log('Error');
        console.log(x);
    }, function completed () {
        console.log('Completed');
    });

function getNumbers (nums) {
    return new Promise(function (resolve, reject) {
        resolve(nums);
    });
}

虽然我只得到完整的数组（即[ 1, 2, 3, 54, 3, 22, 323, 23, 11, 2 ]）。 RxJS 不应该把结果分开吗？我希望它至少有一些逻辑。

谢谢

Answer 1

不，它不会隐式地将它们分开。如果您想拆分它们，请使用 flatMap 将数组展平：

 rx.Observable
    .fromPromise(getNumbers([1,2,3,54,3,22,323,23,11,2]))
    .flatMap(function(x) { return x; })
    .distinct()
    .subscribe(function next (x) {
        console.log('Next');
        console.log(x);
    }, function error (x) {
        console.log('Error');
        console.log(x);
    }, function completed () {
        console.log('Completed');
    });