我们正试图在我们公司建立我们自己的形式场组件。我们试图这样包装材料设计的组件:

字段:

<mat-form-field>
    <ng-content></ng-content>
    <mat-hint align="start"><strong>{{hint}}</strong> </mat-hint>
    <mat-hint align="end">{{message.value.length}} / 256</mat-hint>
    <mat-error>This field is required</mat-error>
</mat-form-field>

文本框:

<field hint="hint">
    <input matInput 
    [placeholder]="placeholder" 
    [value]="value"
    (change)="onChange($event)" 
    (keydown)="onKeydown($event)" 
    (keyup)="onKeyup($event)" 
    (keypress)="onKeypress($event)">
</field>

用法:

<textbox value="test" hint="my hint"></textbox>

结果大致如下:

<textbox  placeholder="Personnummer/samordningsnummer" value="" ng-reflect-placeholder="Personnummer/samordningsnummer">
  <field>
    <mat-form-field class="mat-input-container mat-form-field">
      <div class="mat-input-wrapper mat-form-field-wrapper">
        <div class="mat-input-flex mat-form-field-flex">
          <div class="mat-input-infix mat-form-field-infix">
            <input _ngcontent-c4="" class="mat-input-element mat-form-field-autofill-control" matinput="" ng-reflect-placeholder="Personnummer/samordningsnummer" ng-reflect-value="" id="mat-input-2" placeholder="Personnummer/samordningsnummer" aria-invalid="false">
            <span class="mat-input-placeholder-wrapper mat-form-field-placeholder-wrapper"></span>
          </div>
        </div>
        <div class="mat-input-underline mat-form-field-underline">
          <span class="mat-input-ripple mat-form-field-ripple"></span>
        </div>
        <div class="mat-input-subscript-wrapper mat-form-field-subscript-wrapper"></div>
      </div>
    </mat-form-field>
  </field>
</textbox>

但是我在控制台得到“mat-form-field必须包含MatFormFieldControl”。我猜这与mat-form-field不直接包含matinput字段有关。但它包含了它,只是在ng-content投影中。

以下是闪电战: https://stackblitz.com/edit/angular-xpvwzf


当前回答

部分解决方案是将材料表单字段包装在自定义组件中,并在其上实现ControlValueAccessor接口。除了内容投影之外,效果几乎是一样的。

参见Stackblitz的完整示例。

我在CustomInputComponent中使用了FormControl(响应式表单),但如果你需要更复杂的表单元素,FormGroup或FormArray也应该工作。

app.component.html

<form [formGroup]="form" (ngSubmit)="onSubmit()">

  <mat-form-field appearance="outline" floatLabel="always" color="primary">
    <mat-label>First name</mat-label>
    <input matInput placeholder="First name" formControlName="firstName" required>
    <mat-hint>Fill in first name.</mat-hint>
    <mat-error *ngIf="firstNameControl.invalid && (firstNameControl.dirty || firstNameControl.touched)">
      <span *ngIf="firstNameControl.hasError('required')">
        You must fill in the first name.
      </span>
    </mat-error>
  </mat-form-field>

  <custom-input
    formControlName="lastName"
    [errorMessages]="errorMessagesForCustomInput"
    [hint]="'Fill in last name.'"
    [label]="'Last name'"
    [isRequired]="true"
    [placeholder]="'Last name'"
    [validators]="validatorsForCustomInput">
  </custom-input>

  <button mat-flat-button
    color="primary"
    type="submit"
    [disabled]="form.invalid || form.pending">
    Submit
  </button>

</form>

custom-input.component.html

<mat-form-field appearance="outline" floatLabel="always" color="primary">
  <mat-label>{{ label }}</mat-label>

  <input
    matInput
    [placeholder]="placeholder"
    [required]="isRequired"
    [formControl]="customControl"
    (blur)="onTouched()"
    (input)="onChange($event.target.value)">
  <mat-hint>{{ hint }}</mat-hint>

  <mat-error *ngIf="customControl.invalid && (customControl.dirty || customControl.touched)">
    <ng-container *ngFor="let error of errorMessages">
    <span *ngFor="let item of error | keyvalue">
      <span *ngIf="customControl.hasError(item.key)">
        {{ item.value }}
      </span>
    </span>
    </ng-container>
  </mat-error>
</mat-form-field>

其他回答

在我的例子中,输入元素上漏掉了“onChanges()”的一个右括号,因此输入元素显然根本没有被呈现:

<input mat-menu-item 
      matInput type="text" 
      [formControl]="myFormControl"
      (ngModelChange)="onChanged()>
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';

不要忘记在前面添加< table> </table>

 <mat-form-field>
        <mat-label>Filter</mat-label>
        <input matInput (keyup)="applyFilter($event)" placeholder="Ex. Helium" #input>
      </mat-form-field>

不要忘记在最后添加< table> </table>

<tr class="mat-row" *matNoDataRow>
<td class="mat-cell" colspan="4">
   No data matching the filter "{{input.value}}"
</td>
</tr>

在组件中使用提供者。ts文件

@Component({
 selector: 'your-selector',
 templateUrl: 'template.html',
 styleUrls: ['style.css'],
 providers: [
 { provide: MatFormFieldControl, useExisting: FormFieldCustomControlExample }   
]
})

我在一次Karma测试中遇到了问题

正如大多数答案已经指出的那样,缺失的模块会导致问题,它们也必须重新导入到Karma TestBed中。此外,似乎我们还需要导入BrowserAnimationsModule来使一切正常工作。

在我下面的代码中,我注释了一些可能对你没用的模块,但其他4个导入肯定会有帮助!

beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ EventFormComponent ],
      imports: [
        # HttpClientTestingModule,
        # RouterTestingModule,
        ReactiveFormsModule,
        MatFormFieldModule,
        MatInputModule,
        BrowserAnimationsModule,
        # TranslateModule.forRoot(),
      ],
    })
    .compileComponents();
  }));

你可以尝试按照这个指南来实现/提供你自己的MatFormFieldControl