我想写的服务来获得客户的名单,但我不知道从嵌套promose回报客户的列表中返回的对象数组。角2如何从嵌套承诺
请帮我在这先谢谢了。
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 [];
});
});
}
}
有什么问题
.then(...)
电话吗?你在哪里以及如何调用'getCustomerList()'? –我不知道如何来回报客户名单'getCustomersList()'就是这个代码里面有一些问题了'getCustomersList()'我无法弄清楚 – Sundar
'返回Promise.resolve(()=> {。 ..})'用一个函数来解析,它不会调用它。是否有一个原因,它不应该'返回this.connect()...'? – estus