Angular 2如何从嵌套的promise中返回对象数组

Question

我正在尝试编写一个服务来获取客户列表，但我不知道从嵌套促销中返回客户列表。

请提前帮我解决这个问题。

import { Injectable } from '@angular/core';
import { SQLite } from 'ionic-native';

@Injectable()
export class CustomerService {
    private sDBName:string;
    private db;
    private isDBExist:boolean = false;

    constructor() {}

    setDBName(sDBName:string) {
        this.sDBName = sDBName;
    }

    connect():Promise<any> {        
        this.db = new SQLite();
        return this.db.openDatabase({
            name: this.sDBName,
            location: 'default'
        });
    }
    getCustomersList():Promise<any> {
        return Promise.resolve(()=>{            
            return this.connect().then(()=>{                
                this.isDBExist = true;
                let sql = 'SELECT * FROM customer ORDER BY customer_id DESC LIMIT 10';
                return this.db.executeSql(sql, {}).then((result)=>{ 
                    let customers = [];             
                    for(let i=0; i<result.rows.length; i++) {
                        customers.push(result.rows.item(i));
                    }
                    return customers;
                },(err)=>{
                    this.debug('Unable to select customers', err);
                    return [];
                });
            },(err)=>{
                this.debug('Unable to open database', err);
                return [];
            });
        });
    }
}

Answer 1

你需要用.then(...)like链接调用

this.getCustomerList().then(result => this.myArray = result);