Angular和TypeScript：我應該如何處理

Question

我有一個關於如何處理Angular異步調用的問題。

我正在從控制器的服務中調用以下兩個方法來獲取對象，即“ categoryInfo”

如何獲得以下方法來返回categoryInfo並正確打印它？

調用方（在控制器中）兩種方法↓

console.log(this.service.getLargeCategoryList()); ←※Prints out as "undefined"

方法1↓

public getLargeCategoryList(): any {
            console.log('Inside getLargeCategoryList');
            this.getCategoryInfoList('', ServiceUrls.URL_FOR_TOP_CATEGORY)
                .then((data) => {
                var categoryInfo: ILCategoryInfoRes[] = data.categoryInfo;
                return categoryInfo;　←※Appears to be skipped
            }, function (data) {
                    console.log(data);
                    alert('Error');
                    return null;
                });
            console.log('Coming out of getLargeCategoryList');
        }

方法2↓

private getCategoryInfoList(parameter: any, serviceUrl: string): ng.IPromise<any> {

                var def = this.qService.defer();

                this.httpService({
                        method: 'POST',
                        url: serviceUrl,
                        data: parameter
                }).success(function (data: any, status, headers, config) {
                     //Success
                    var categoryInfo: ILCategoryInfoRes[];
                    var statusInfo: IStatus[];

                    //categoryInfo = data.categoryInfo;
                    statusInfo = data.status;

                    if (statusInfo[0].statusCode == '000') {
                        def.resolve(data);
                    } else {
                        def.resolve(statusInfo);
                    }
                 }).error(function (data, status, headers, config){
                     //Error 
                    def.reject("Failed");
                 });
                return def.promise;
            }

Answer 1

您將需要從此函數中返回承諾：

public getLargeCategoryList(): any {
  console.log('Inside getLargeCategoryList');
  return this.getCategoryInfoList('', ServiceUrls.URL_FOR_TOP_CATEGORY)
    .then((data) => {
      var categoryInfo: ILCategoryInfoRes[] = data.categoryInfo;
      return categoryInfo;　←※Appears to be skipped
    }, function (data) {
      console.log(data);
      alert('Error');
      return null;
    });
  console.log('Coming out of getLargeCategoryList');
}

處理它，就好像它返回一個promise，而不是一個值，因為它是一個異步操作：

this.service.getLargeCategoryList()
  .then((data) => {
    console.log(data);
  }):