Html Angular 2复选框双向数据绑定

我对Angular2还比较陌生，我有一个小问题:

在我的Login-Component-HTML中，我有两个复选框，我希望以双向数据绑定的方式将它们绑定到Login-Component-Typecript.

This is the HTML:个

<div class="checkbox">
<label>
    <input #saveUsername [(ngModel)]="saveUsername.selected" type="checkbox" data-toggle="toggle">Save username
</label>
</div>

And this is the Component.ts:

import { Component, OnInit }    from '@angular/core';
import { Router }               from '@angular/router';
import { Variables }            from '../../services/variables';

@Component({
    selector: 'login',
    moduleId: module.id,
    templateUrl: 'login.component.html',
    styleUrls: ['login.component.css']
})


export class LoginComponent implements OnInit {

    private saveUsername: boolean = true;
    private autoLogin: boolean = true;
    constructor(private router: Router, private variables: Variables) { }

    ngOnInit() { 
        this.loginValid = false;
        // Get user name from local storage if you want to save

        if (window.localStorage.getItem("username") === null) {
           this.saveUsername = true;
           this.autoLogin = true;
           console.log(this.saveUsername, this.autoLogin);
        } else {
           console.log("init", window.localStorage.getItem("username"));
        }
    }

    login(username: string, password: string, saveUsername: boolean, autoLogin: boolean) {
        this.variables.setUsername(username);
        this.variables.setPassword(password);
        this.variables.setIsLoggedIn(true);
        console.log(saveUsername, autoLogin);
        //this.router.navigate(['dashboard']);
    }

如果单击复选框，则在控制器(组件)中获得正确的值.

但是如果我在组件中更改了例如saveUsername的值，复选框不会"获取"新值.

所以我不能操作组件中的复选框(就像我想在组件中的ngOnInit中操作的那样).

谢谢你的帮忙!