如何从Angular2本地存储中保存和检索数据？

Question

我能够在浏览器中存储身份验证令牌localstorage,但我无法将其作为字符串检索.我找不到任何关于如何做到这一点的例子.

Answer 1

您可以自己编写一个服务来封装序列化和反序列化:

export class StorageService {
    write(key: string, value: any) {
        if (value) {
            value = JSON.stringify(value);
        }
        localStorage.setItem(key, value);
    }

    read<T>(key: string): T {
        let value: string = localStorage.getItem(key);

        if (value && value != "undefined" && value != "null") {
            return <T>JSON.parse(value);
        }

        return null;
    }
}

在bootstrap通话中将其添加到您的提供商:

bootstrap(App, [ ..., StorageService]);

或者在根组件中:

@Component({
    // ...
    providers: [ ..., StorageService]
})
export class App {
    // ...
}

然后在您需要它的组件中,只需将其注入构造函数中:

export class SomeComponent {
    private someToken: string;

    constructor(private storageService: StorageService) {
        someToken = this.storageService.read<string>('my-token');
    }

    // ...
}