Question

在我的角度项目中，我有两个ts文件，如下所示：

Data.ts

import { Injectable } from '@angular/core';
import { MyStorage } from '../storage';

@Injectable()
export class itemFromStorage {
constructor(public storage: Storage) {  

}

    GetItemDataFromStorage(current){        
        this.storage.get(current).then((val) => {
          return val;  //????    
        }); 
   };    

}

Main.ts

import { itemFromStorage } from '../data'

export class item_thumb {
    constructor(public itemStorage: itemFromStorage) { 

    };  

   fetchThumbData(){
     var data = this.itemStorage.GetItemDataFromStorage(this.dataNumber);
     console.log(data);//????
   }
}

从data.ts，如何将数据值返回到main.ts？

Answer 1

你的data.ts方法应该只返回请求本身，而不是订阅它：

    GetItemDataFromStorage(current){        
        return this.storage.get(current);
   };

并在您的main.ts方法中订阅并接收数据：

   fetchThumbData(){
     var data = this.itemStorage.GetItemDataFromStorage(this.dataNumber).then((data) => {
          console.log(data);//???? 
        }); 

   }

Answer 2

您的Data.ts很可能会返回一个承诺 Main.ts

export class item_thumb {
    constructor(public itemStorage: itemFromStorage) { 
    };  
   fetchThumbData(){
     let promise = this.itemStorage.GetItemDataFromStorage(this.dataNumber);
     promise.then(data => console.log(data));     
   }
}

要同步获取值：Get the value of a Javascript Promise in a synchronous way

从一个ts到另一个的角度返回值

2 个答案: