问题
We are trying to build our own form-field-Components at our Company. We are trying to wrap material design's Components like this:
field:
<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>
textbox:
<field hint="hint">
<input matInput
[placeholder]="placeholder"
[value]="value"
(change)="onChange($event)"
(keydown)="onKeydown($event)"
(keyup)="onKeyup($event)"
(keypress)="onKeypress($event)">
</field>
Usage:
<textbox value="test" hint="my hint"></textbox>
This results in approximately this:
<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>
But I'm getting "mat-form-field must contain a MatFormFieldControl" in the console. I guess this has to do with mat-form-field not directly containing a matInput-field. But it is containing it, it's just withing the ng-content projection.
Here is a blitz: https://stackblitz.com/edit/angular-xpvwzf
回答1:
Unfortunately content projection into mat-form-field is not supported yet. Please track the following github issue to get the latest news about it.
By now the only solution for you is either place your content directly into mat-form-field component or implement a MatFormFieldControl class thus creating a custom form field component.
回答2:
I had this issue. I imported MatFormFieldModule at my main module, but forgot to add MatInputModule to the imports array, like so:
import { MatFormFieldModule, MatInputModule } from '@angular/material';
@NgModule({
imports: [
MatFormFieldModule,
MatInputModule
]
})
export class AppModule { }
Hope it helps.
More info here.
回答3:
Solution 1
import MatInputModule inside module i.e. app.module.ts
import { MatInputModule } from '@angular/material';
@NgModule({
imports: [
// .......
MatInputModule
// .......
]
})
export class AppModule { }
Solution 2
Be sure to add matInput and it is case-sensitive.
<input matInput type="text" />
回答4:
Quoting from the official documentation here:
Error: mat-form-field must contain a MatFormFieldControl
This error occurs when you have not added a form field control to your form field. If your form field contains a native or element, make sure you've added the matInput directive to it and have imported MatInputModule. Other components that can act as a form field control include , , and any custom form field controls you've created.
回答5:
This can also happen if you have a proper input within a mat-form-field, but it has a ngIf on it. E.g.:
<mat-form-field>
<mat-chip-list *ngIf="!_dataLoading">
<!-- other content here -->
</mat-chip-list>
</mat-form-field>
In my case, mat-chip-list is supposed to "appear" only after its data is loaded. However, the validation is performed and mat-form-field complains with
mat-form-field must contain a MatFormFieldControl
To fix it, the control must be there, so I have used [hidden]:
<mat-form-field>
<mat-chip-list [hidden]="_dataLoading">
<!-- other content here -->
</mat-chip-list>
</mat-form-field>
An alternative solution is proposed by Mosta: move *ngIf for mat-form-field:
<mat-form-field *ngIf="!_dataLoading">
<mat-chip-list >
<!-- other content here -->
</mat-chip-list>
</mat-form-field>
回答6:
I'm not sure if it could be this simple but I had the same issue, changing "mat-input" to "matInput" in the input field resolved the problem. In your case I see "matinput" and it's causing my app to throw the same error.
<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">
"matinput"
"matInput"
回答7:
If anyone got stuck with this error after attempting to nest a <mat-checkbox>, be of good cheer! It doesn't work inside a <mat-form-field> tag.
回答8:
I had this issue too, and I have <mat-select> element in my template, when I import the MatSelectModule into Module, it works, it doesn't make science, but stil hope it can help you.
import { MatSelectModule } from '@angular/material/select';
imports: [
BrowserModule,
BrowserAnimationsModule,
MatSidenavModule,
MatButtonModule,
MatIconModule,
MatToolbarModule,
MatFormFieldModule,
MatProgressSpinnerModule,
MatInputModule,
MatCardModule,
MatSelectModule
],
<div class="example-container">
<mat-form-field>
<input matInput placeholder="Input">
</mat-form-field>
<mat-form-field>
<textarea matInput placeholder="Textarea"></textarea>
</mat-form-field>
<mat-form-field>
<mat-select placeholder="Select">
<mat-option value="option">Option</mat-option>
</mat-select>
</mat-form-field>
</div>
回答9:
You could try following this guide and implement/provide your own MatFormFieldControl
回答10:
I had accidentally removed the matInput directive from the input field which caused the same error.
eg.
<mat-form-field>
<input [readOnly]="readOnly" name="amount" formControlName="amount" placeholder="Amount">
</mat-form-field>
fixed code
<mat-form-field>
<input matInput [readOnly]="readOnly" name="amount" formControlName="amount" placeholder="Amount">
</mat-form-field>
回答11:
Unfortunately I can't just comment on some already good answers as I don't have the SO points yet, however, there are 3 key modules that you'll need to make sure you are importing into your component's parent module, aside from what you have to import into your component directly. I wanted to briefly share them and highlight what they do.
- MatInputModule
- MatFormFieldModule
- ReactiveFormsModule
The first two are for Angular Material. A lot of people new to Angular Material will instinctively come across one of these and not realize that building a form requires both.
So what's the difference between them?
MatFormFieldModule encompasses all the different types of form fields that Angular Material has available. This is more of a high level module for form fields in general, whereas the MatInputModule is specifically for 'input' field types, as opposed to select boxes, radio buttons, etc.
The third item on the above list is Angular's Reactive Forms Module. The Reactive Forms Module is responsible for a ton of under-the-hood Angular love. If you are going to work with Angular, I highly recommend that you spend some time reading Angular Docs. They have all of your answers. Building applications rarely DOESN'T involve forms, and more often than not, your application will involve reactive forms. For that reason, please take the time to read these two pages.
Angular Docs: Reactive Forms
Angular Docs: Reactive Forms Module
The first doc 'Reactive Forms' will be your most powerful weapon as you get started, and the second doc will be your most power weapon as you get on to more advanced applications of Angular Reactive Forms.
Remember, these need to be imported directly into your component's module, not the component you are using them in. If I remember correctly, in Angular 2, we imported the entire set of Angular Material modules in our main app module, and then imported what we needed in each of our components directly. The current method is much more efficient IMO because we are guaranteed to import the entire set of Angular Material modules if we only use a few of them.
I hope this provides a bit more insight into building forms with Angular Material.
回答12:
If all of the main code structure/configuration answers above don't solve your issue, here's one more thing to check: make sure that you haven't in some way invalidated your <input> tag.
For instance, I received the same mat-form-field must contain a MatFormFieldControl error message after accidentally putting a required attribute after a self-closing slash /, which effectively invalidated my <input/>. In other words, I did this (see the end of the input tag attributes):
wrong:
<input matInput type="text" name="linkUrl" [formControl]="listingForm.controls['linkUrl']" /required>
right:
<input matInput type="text" name="linkUrl" [formControl]="listingForm.controls['linkUrl']" required/>
If you make that mistake or something else to invalidate your <input>, then you could get the mat-form-field must contain a MatFormFieldControl error. Anyway, this is just one more thing to look for as you're debugging.
回答13:
MatRadioModule won't work inside MatFormField. The docs say
This error occurs when you have not added a form field control to your form field. If your form field contains a native or element, make sure you've added the matInput directive to it and have imported MatInputModule. Other components that can act as a form field control include < mat-select>, < mat-chip-list>, and any custom form field controls you've created.
回答14:
In my case, one of my closing parenthesis for "onChanges()" were missed on the input element and thus the input element was apparently not being rendered at all:
<input mat-menu-item
matInput type="text"
[formControl]="myFormControl"
(ngModelChange)="onChanged()>
回答15:
The same error can occur if you have a mat slide within a mat from field as the only element in my case I had
<mat-form-field>
<mat-slide-toggle [(ngModel)]="myvar">
Some Text
</mat-slide-toggle>
</mat-form-field>
This might happen if you had several attributes within the <mat-form-field>
Simple solution was to move the slide toggle to the root
回答16:
A partial solution is to wrap the material form field in a custom component and implement the ControlValueAccessor interface on it. Besides content projection the effect is pretty much the same.
See full example on Stackblitz.
I used FormControl (reactive forms) inside CustomInputComponent but FormGroup or FormArray should work too if you need a more complex form element.
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>
回答17:
In my case I changed this:
<mat-form-field>
<input type="email" placeholder="email" [(ngModel)]="data.email">
</mat-form-field>
to this:
<mat-form-field>
<input matInput type="email" placeholder="email" [(ngModel)]="data.email">
</mat-form-field>
Adding the matInput directive to the input tag was what fixed this error for me.
回答18:
if anyone is trying to nest a <mat-radio-group> inside a <mat-form-field>
like below, you will get this error
<mat-form-field>
<!-- <mat-label>Image Position</mat-label> -->
<mat-radio-group aria-label="Image Position" [(ngModel)]="section.field_1">
<mat-radio-button value="left">Left</mat-radio-button>
<mat-radio-button value="right">Right</mat-radio-button>
</mat-radio-group>
</mat-form-field>
remove the parent <mat-form-field> tags
回答19:
Note Some time Error occurs, when we use "mat-form-field" tag around submit button like:
<mat-form-field class="example-full-width">
<button mat-raised-button type="submit" color="primary"> Login</button>
</mat-form-field>
So kindly don't use this tag around submit button
回答20:
You might have missed to import MatInputModule
来源：https://stackoverflow.com/questions/46705101/mat-form-field-must-contain-a-matformfieldcontrol