Question

这是我编译时抛出错误的代码：

export class NoticeService {
  public notice: Observable<any>;
  private observer: any;

  constructor(private translate: TranslateService) {
    this.notice = new Observable(observer => {
      this.observer = observer;
    }).share();
  }

  create(value: string) {
    let translatedValue = this.translate.get(value).value;
    this.observer.next(translatedValue);
  }
}

console.log(this.translate.get(value))的输出是：

ScalarObservable {_isScalar: true, value: "Some proper value!", etc.

console.log(translatedValue)的输出是：

"Some proper value!"

错误是：

ERROR in [default] /somePath/notice.service.ts:21:52
Property 'value' does not exist on type 'Observable<any>'.

第21行是：

let translatedValue = this.translate.get(value).value;

可能出现什么问题？

更新

我正在使用ng2-translate，这是get方法：

/**
 * Gets the translated value of a key (or an array of keys)
 * @param key
 * @param interpolateParams
 * @returns {any} the translated key, or an object of translated keys
 */
TranslateService.prototype.get = function (key, interpolateParams) {
    var _this = this;
    if (!key) {
        throw new Error('Parameter "key" required');
    }
    // check if we are loading a new translation to use
    if (this.pending) {
        return this.pending.map(function (res) {
            return _this.getParsedResult(_this.parser.flattenObject(res), key, interpolateParams);
        });
    }
    else {
        var translations = void 0;
        if (this.translations[this.currentLang]) {
            translations = this.parser.flattenObject(this.translations[this.currentLang]);
        }
        return Observable_1.Observable.of(this.getParsedResult(translations, key, interpolateParams));
    }
};

Answer 1

由于返回了一个observable，您需要订阅它。像这样：

create(value: string) {
  this.translate.get(value).subscribe(translatedValue => { 
    this.observer.next(translatedValue);
  });
}

而不是试图直接从中获取价值......

Answer 2

对于同时搜索更方便方法的用户：同时ng2-translate的开发人员添加了'instant（）'方法直接加载值（必须首先加载TranslationLoader才能使其工作）：请参阅https://github.com/ocombe/ng2-translate/issues/20或者，如果在使用translate.instant（key）之前没有加载TranslationLoader并且只有键可见，则通过等待onLangChange事件处理另一个问题：{{3 }}

constructor (private translate : TranslateService){
     translate.onLangChange.subscribe((event: LangChangeEvent) => {
        ...
        let lesson  = new Lesson();

        lesson.title    =  translate.instant("lesson_1_title");

      });
}

不要忘记在.ts控制器文件的标题中从ng2-translate加载LangChange：

import {TranslatePipe,TranslateService, LangChangeEvent} from 'ng2-translate/ng2-translate';

打字稿错误：'Observable <any>'类型中不存在属性'value'

2 个答案: