Question

我们有2个功能：

class AndroidGameFragment () : AndroidFragmentApplication(){






    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        super.onCreateView(inflater, container, savedInstanceState)
        val config = AndroidApplicationConfiguration()




        return initializeForView(MyGdxGame(), config)
    }






}

在我的函数正文中，您可以看到我正在调用submitEstateObject = () => { // if (!this.state.formIsValid) { // this.setState({ showFieldErrors: true }) // console.log(this.state) // } else { //this.setState({ isLoading: true }) console.log('Category', this.state.estateForm.category.value) console.log('Type', this.state.estateForm.type.value) console.log('Params', this.state.estateParams) console.log('ContactsAndOwners', this.state.contactsAndOwners) console.log('Photos', this.state.photos) //Submit photos const test = this.uploadPhotos() // WAIT UNTILL FUNC RETURN ARRAY! //AFTER TEST WAS DONE RUN CODE BELOW console.log('Test', test) console.log('Test2') //} }。此func必须返回对象数组，然后我要继续执行下面的另一个代码。该怎么做？

uploadPhotos

Answer 1

您要使用Promise.all(promiseArray)

代替console.log(photosToSave)

尝试

Promise.all(photosToSave).then(arr => console.log(arr))
                         .catch(err => console.log('Something failed', err)

Answer 2

有两种方式处理承诺。通过回调（解决）或实际返回承诺。我要解决后者。

每次您在承诺中退还某些东西时，都会将其作为承诺退还。因此，您需要在promise中包装对返回promise的函数的调用。

示例：

function ajaxCall(url) {
  return return AJAXRequest(url);
}

function getSearch() {
  ajaxCall('http://test.com')  // Calling a function that returns an ajax call.
  .then(function (ajaxResponse) {
    // code that handles ajaxRespons
  });
}

但是在您的uploadPhotos方法中，什么也不返回。您需要返回Promise.all。

  // the equivalent to my ajaxCall example
  uploadPhotos = () => {
    // other code
    return Promise.all(photosToSave) // added 'return' and removed the return statement inside the Promise.all method.
  }

然后应将响应作为承诺处理。

// the same as in my getSearch example
const test = this.uploadPhotos()
.then(function (ajaxResponse) {
  //AFTER TEST WAS DONE RUN CODE BELOW
  console.log('Test', ajaxResponse)
});

更多阅读内容：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise

如何等到函数返回结果

2 个答案: