&#39; IPromise <任何>&#39;不能分配类型&#39;承诺<任何>&#39;

时间:2017-11-10 13:20:31

标签: angularjs typescript angular-ui-router angular-ui-bootstrap

我在用户更改标签时建立确认对话框。代码工作正常,但 tslint 抱怨类型不匹配。控制器看起来像:

export class MyController implements ng.IController {

    constructor(private $transitions: TransitionService,
                private $translate: angular.translate.ITranslateService) {
        'ngInject';

        $transitions.onStart({}, () =>
            this.alert
                .showConfirm(
                    this.$translate.instant('dialogs.confirmLeave.content'),
                    this.$translate.instant('dialogs.confirmLeave.title')
                )
                .then(() => true)
                .catch(() => false)
        );
    }

    ...
}

this.alert.showConfirm最终从angular-ui-bootstrap调用this.$uibModal.open()。这给出了以下警告:

error TS2345: Argument of type '() => IPromise<boolean>' is not assignable to parameter of type 'TransitionHookFn'.
  Type 'IPromise<boolean>' is not assignable to type 'boolean | void | TargetState | Promise<boolean | void | TargetState>'.
    Type 'IPromise<boolean>' is not assignable to type 'Promise<boolean | void | TargetState>'.
      Types of property 'then' are incompatible.
        Type '{ <TResult>(successCallback: (promiseValue: boolean) => TResult | IPromise<TResult>, errorCallbac...' is not assignable to type '<TResult1 = boolean | void | TargetState, TResult2 = never>(onfulfilled?: (value: boolean | void ...'.
          Type 'IPromise<any>' is not assignable to type 'Promise<any>'.
            Types of property 'then' are incompatible.
              Type '{ <TResult>(successCallback: (promiseValue: any) => TResult | IPromise<TResult>, errorCallback?: ...' is not assignable to type '<TResult1 = any, TResult2 = never>(onfulfilled?: (value: any) => TResult1 | PromiseLike<TResult1>...'.
                Type 'IPromise<any>' is not assignable to type 'Promise<any>'.

有关如何解决此问题的任何想法?

1 个答案:

答案 0 :(得分:3)

它看起来像this.alert.showConfirm(),它不会返回真正的Promise。尝试将结果包装在Promise

export class MyController implements ng.IController {

    constructor(private $transitions: TransitionService,
                private $translate: angular.translate.ITranslateService) {
        'ngInject';

        $transitions.onStart({}, () =>
            Promise.resolve(
                this.alert
                    .showConfirm(
                        this.$translate.instant('einsteinsst.dialogs.confirmLeave.content'),
                        this.$translate.instant('einsteinsst.dialogs.confirmLeave.title')
                    )
            )
            .then(() => true)
            .catch(() => false)
        );
    }

    ...
}

Promise.resolve()会将任何可执行的内容(即实现IPromise的任何内容)转换为真正的Promise,但IPromise界面与Promise不直接兼容。

有关详细信息,请参阅docs