Angular 6 错误显示 'mat-form-field' 不是已知元素：

Question

您好，我正在使用 angular 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html这样

<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"
  },

我遇到了这个错误

'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. ("

为什么我会遇到这个错误我不得不花太多时间来解决这个问题但在我错的地方没有得到任何解决方案我也搜索堆栈溢出在这里一些找到解决方案但没有解决我的问题你可以吗请帮我找出这个错误

感谢您解决我的问题

Answer 1

查看你的错误ng:///AppRoutingModule/LoginComponent.html@11:2

我可以得出结论，您在 AppRoutingModule 中声明了 LoginComponent，但没有在那里导入 MatFormFieldModule。

将LoginComponent移动到AppModule的declarations数组：

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

或在 AppRoutingModule 中导入 MatFormFieldModule 或一些 SharedModule:

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

另请参阅：

Answer 2

尝试导入

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

在你的模块中然后注入

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

Answer 3

我遇到了同样的问题，我的解决方法是 MatFormFieldModule、MatInputModule、MatSelectModule，已添加到我的 Material 模块

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

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

Answer 4

如果您有 2 个应用模块示例：app-routing.module.ts 和 app.module.ts 将 CommonModule 导入第二个 (app-routing.module.ts)

Answer 5

您需要导入MatSelectModule:

{MatSelectModule} from '@angular/material/select';

然后将其添加到导入数组中：

 imports: [
    BrowserModule,
    BrowserAnimationsModule,
    CommonModule,
    RouterModule,
    AppRoutingModule,
   // MaterialModule,
   ...modules,
   MatSelectModule
  ]

Answer 6

我也遇到了这个问题，这是由于 material re-downloading 安装失败造成的/安装为我修复了它..

ng 添加@angular/material

Answer 7

如果您使用的是 material-ui 组件，则有一个 api 选项卡可以让您知道需要将哪个模块导入到 app.module.ts 文件中. https://material.angular.io/components/autocomplete/api

Answer 8

尽管加载了所有正确的模块，我也看到了这一点。

原来我忘了添加新组件，确保将它添加到模块的 declarations 数组中。

Answer 9

对我来说，有必要在模块中声明组件。

@NgModule({
  declarations: 
    [
      EducationModalComponent,
    ],

Angular 6 错误显示 'mat-form-field' 不是已知元素：

Angular 6 error show to 'mat-form-field' is not a known element:

angular-material

angular

angular6