如何检测Angular 2中的属性是否发生了变化？

Question

我有一个简单的类,看起来像这样:

export class MessagesPage  {

    @ViewChild(Content) content: Content;

    public message  = '';
    public messages = [];

    public state = 'general';
}

在类中是否可以检测state属性是否已更改？

Answer 1

让他们成为吸毒者和二传手.没有其他方法可以获得有关更改的通知:

export class MessagesPage  {

    @ViewChild(Content) content: Content;

    public message  = '';
    public messages = [];

    private _state = 'general';
    public get state() { return this._state; }
    public set state(value:string) { 
      this._state = value;
      console.log('state changed', this._state);
    }
}