混合应用程序使用sqlite和angular 2进行数据库调用

Question

我目前正在使用离子2开发移动应用程序。我有这组代码需要从sqlite检索数据，然后进一步将此值用于其他一些功能。见下文

this.credentials = _credentials;
let username = _credentials.username;
let password = _credentials.password;
let cVersion;
**this.localDbService.getcVersion().then((data) => {
    cVersion = data;
});**
console.log(cVersion);
//build http header and make http call to servlet to retrieve details
let myHeaders: Headers = new Headers();
let digest = btoa(`${username}:${password}`);

cVersion的值为null，因为我猜测对sqlite的调用是异步的。我认为可以解决的一个快速解决方案是在数据库调用函数getcVersion中包含所有下一个逻辑，但有没有解决方案，比如等待数据库调用结束然后继续执行？

谢谢， 阿什利

Answer 1

Replace this

this.credentials = _credentials; 
let username = _credentials.username; 
let password = _credentials.password; 
let cVersion;

 this.localDbService.getcVersion()
.then((data) => { 

cVersion = data;

console.log(cVersion);

//build http header and make http call to servlet to retrieve details 
let myHeaders: Headers = new Headers(); 
let digest = btoa(`${username}:${password}`);

 });

干杯！