AngularJs 2 – 创建多个服务实例

StateService类：

@Injectable ()
class StateService {

    public log : string;
    static count : number = 0;

    constructor () {
        this.log = '';
        StateService.count++;
        this.writeToLog ('CREATED '+StateService.count+' at ' + new Date().toString());
    }

    public writeToLog (text : string) : void {
        this.log += text + 'n';
    }
}

零件 ：

@Component ({
    selector : 'Sub-Component',template : `<hr>
            This is the Sub-Component !
            <BR>
            StateService Log : 
            <pre>{{ _stateService.log }}</pre>
            <button (click)="WriteToLog ()">Write to log</button>
            `,providers : [StateService]
})

export class SubComponent {
    constructor (private _stateService : StateService) {
    }

    public WriteToLog () : void {
        this._stateService.writeToLog ('From Sub-Component - This is '+new Date().toString());
    }
}

代码here的实例

除了服务创建一次，当每个组件调用WriteToLog方法时，输出在每个组件中是相同的，但不是。

输出示例：

App-Component可以输出以下内容：

Instance 1 – Created at Thu Jan 21 2016 11:43:51

From App-Component – This is Thu Jan 21 2016 11:43:54

From App-Component – This is Thu Jan 21 2016 11:43:55

子组件可以输出：

Instance 2 – Created at Thu Jan 21 2016 11:43:51

From Sub-Component – This is Thu Jan 21 2016 11:43:57

From Sub-Component – This is Thu Jan 21 2016 11:43:58

所以看起来服务的2个实例被创建(实例1的实例2)

我只想要一个实例;)，当我在日志中追加字符串时，这必须出现在两个组件中。

感谢您的帮助