"mat-form-field"中的Angular 6错误显示不是已知元素:

Question

嗨我使用角度6,我的代码如下:

import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RouterModule, Routes } from '@angular/router';




import { AppComponent } from './app.component';
import { AppRoutingModule } from './app.routing.module';


import { MatButtonModule, MatFormFieldModule, MatInputModule, MatRippleModule } from '@angular/material';
//import { MaterialModule } from 'src/app/et-shared/material.module';


const modules = [
  MatButtonModule,
  MatFormFieldModule,
  MatInputModule,
  MatRippleModule
];

@NgModule({
  declarations: [
    AppComponent,
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    CommonModule,
    RouterModule,
    AppRoutingModule,
   // MaterialModule,
   ...modules

  ],
  exports:[
    ...modules
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

和这样的HTML

<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>

我的包裹是这样的

"dependencies": {
    "@angular/animations": "^6.0.0",
    "@angular/cdk": "^6.0.1",
    "@angular/common": "^6.0.0",
    "@angular/compiler": "^6.0.0",
    "@angular/core": "^6.0.0",
    "@angular/forms": "^6.0.0",
    "@angular/http": "^6.0.0",
    "@angular/material": "^6.0.1",
    "@angular/platform-browser": "^6.0.0",
    "@angular/platform-browser-dynamic": "^6.0.0",
    "@angular/router": "^6.0.0",
    "core-js": "^2.5.4",
    "hammerjs": "^2.0.8",
    "rxjs": "^6.0.0",
    "zone.js": "^0.8.26"
  },

我得到了这个错误

'mat-form-field' is not a known element:
1. If 'mat-form-field' is an Angular component, then verify that it is part of this module.
2. If 'mat-form-field' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message. ("

<div class="example-container">
  [ERROR ->]<mat-form-field>
    <input matInput placeholder="Input">
  </mat-form-field>
"): ng:///AppRoutingModule/LoginComponent.html@7:2
'mat-form-field' is not a known element:
1. If 'mat-form-field' is an Angular component, then verify that it is part of this module.
2. If 'mat-form-field' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message. ("
  </mat-form-field>

  [ERROR ->]<mat-form-field>
    <textarea matInput placeholder="Textarea"></textarea>
  </mat-form-field>
"): ng:///AppRoutingModule/LoginComponent.html@11:2
'mat-option' is not a known element:
1. If 'mat-option' is an Angular component, then verify that it is part of this module.
2. If 'mat-option' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message. ("
  <mat-form-field>
    <mat-select placeholder="Select">
      [ERROR ->]<mat-option value="option">Option</mat-option>
    </mat-select>
  </mat-form-field>
"): ng:///AppRoutingModule/LoginComponent.html@17:6
'mat-select' is not a known element:
1. If 'mat-select' is an Angular component, then verify that it is part of this module.
2. If 'mat-select' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message. ("

为什么我得到这个错误我必须花太多时间来解决这个但没有得到任何解决方案,我错了我也搜索堆栈溢出这里找到解决方案,但没有解决我的问题,请你帮我看看这个错误

谢谢你解决我的问题

Answer 1

看着你的错误 ng:///AppRoutingModule/LoginComponent.html@11:2

我可以断定,你声明LoginComponent中AppRoutingModule却没有导入MatFormFieldModule那里.

移动LoginComponent到以下decrations阵列AppModule:

@NgModule({
  declarations: [
    AppComponent,
    LoginComponent
  ],
  ...
})
export class AppModule { }

或进口MatFormFieldModule或一些SharedModule在AppRoutingModule:

@NgModule({
  declarations: [
    LoginComponent,
    ...
  ],
  imports: [
    MatFormFieldModule // or SharedModule that exports MatFormFieldModule
    ...
  ]
  ...
})
export class AppRoutingModule { }

也可以看看:

• Angular 2使用另一个模块中的组件

Answer 2

尝试导入

import { CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';

在你的模块然后注入

@NgModule({
//..your other property,
   schemas: [CUSTOM_ELEMENTS_SCHEMA]
 });

Answer 3

我遇到了同样的问题，对我来说修复的是 MatFormFieldModule、MatInputModule、MatSelectModule，添加到我的 Material 模块中

import { MatFormFieldModule, MatInputModule } from '@angular/material';

@NgModule({
    imports: [
        MatFormFieldModule,
        MatInputModule
    ]
})
export class AppModule { }