如何在AutoComplete Material2中使用[displayWith]显示

Question

我有一个array来自我的API而且我正在使用Material2#AutoComplete过滤这个...它到目前为止工作,但是我很难显示另一个属性而不是选项中的绑定值.

我知道我必须使用displayWith它,但它不能像我期望的那样工作.调用的函数[displayWith]="displayFn.bind(this)">只返回我id,如何获取完整的对象,然后返回nameon函数.

顺便说一句,我仍然想在我的FormControl中绑定id .

一些代码:

零件:

export class AutocompleteOverviewExample {
  stateCtrl: FormControl;
  filteredStates: any;

  states = [
    { 
      id: 1,
      name: 'Alabama'
    },
    {
      id: 2,
      name: 'North Dakota'
    },
    {
      id: 3,
      name: 'Mississippi'
    }
  ];

  constructor() {
    this.stateCtrl = new FormControl();
    this.filteredStates = this.filterStates('');
  }

  onKeyUp(event: Event): void {
    this.filteredStates = this.filterStates(event.target.value);
  }

  filterStates(val: string): Observable<any> {
    let arr: any[];
    console.log(val)
    if (val) {
      arr = this.states.filter(s => new RegExp(`^${val}`, 'gi').test(s.name));
    } else {
      arr = this.states;
    }

    // Simulates request
    return Observable.of(arr);
  }

  displayFn(value) {
    // I want to get the full object and display the name
    return value;
  }
}

模板:

<md-input-container>
  <input mdInput placeholder="State" (keyup)="onKeyUp($event)" [mdAutocomplete]="auto" [formControl]="stateCtrl">
</md-input-container>

<md-autocomplete #auto="mdAutocomplete" [displayWith]="displayFn.bind(this)">
  <md-option *ngFor="let state of filteredStates | async" [value]="state.id">
    {{ state.name }}
  </md-option>
</md-autocomplete>

基本上,它几乎与这个问题相同(不幸的是,两个答案都不正确或抛出错误).

这是PLUNKER.

Answer 1

如果你想要整个对象绑定md-options,那么你应该绑定到选项state和返回state.name,displayFn这样你就不必绑定this.

<md-autocomplete #auto="mdAutocomplete" [displayWith]="displayFn">
  <md-option *ngFor="let state of filteredStates | async" [value]="state">
    {{ state.name }}
  </md-option>
</md-autocomplete>

displayFn(state) {
  return state.name;
}

演示plunker.

如果你想只绑定state.id到md-options,你必须通过循环states找到state.name基于state.id这种方式的结合this是必要的.

<md-autocomplete #auto="mdAutocomplete" [displayWith]="displayFn.bind(this)">
  <md-option *ngFor="let state of filteredStates | async" [value]="state.id">
    {{ state.name }}
  </md-option>
</md-autocomplete>

displayFn(id) {
  if (!id) return '';

  let index = this.states.findIndex(state => state.id === id);
  return this.states[index].name;
}

演示plunker.