'mat-form-field' 不是已知元素 - Angular 5 &材料2 [英] 'mat-form-field' is not a known element - Angular 5 & Material2

问题描述

我正在尝试在使用 Material2 的 Angular 项目中使用 ，但我遇到了障碍.

I'm trying to use <mat-form-field> in an Angular project using Material2 but I've hit a wall.

收到以下错误消息.

Uncaught Error: Template parse errors:
'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. ("[ERROR ->]<mat-form-field>
  <input matInput placeholder="Simple placeholder" required>
</mat-form-field>"): ng:///MaterialModule/SearchComponent.html@0:0
    at syntaxError (compiler.js:485)
    at TemplateParser.parse (compiler.js:24660)
    at JitCompiler._parseTemplate (compiler.js:34471)
    at JitCompiler._compileTemplate (compiler.js:34446)
    at eval (compiler.js:34347)
    at Set.forEach (<anonymous>)
    at JitCompiler._compileComponents (compiler.js:34347)
    at eval (compiler.js:34217)
    at Object.then (compiler.js:474)
    at JitCompiler._compileModuleAndComponents (compiler.js:34216)

这是我的代码.

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule, CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
import { FormGroup, FormControl, FormsModule, ReactiveFormsModule } from '@angular/forms';

import { HttpModule } from '@angular/http';
import { HttpClientModule } from '@angular/common/http';

import {
  MatButtonModule,
  MatFormFieldModule,
  MatInputModule,
  MatRippleModule
} from '@angular/material';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

import { AppComponent } from './app.component';
import { YahooService } from './yahoo.service';
import { SearchComponent } from './search/search.component';

@NgModule({
  exports: [
    MatButtonModule,
    MatFormFieldModule,
    MatInputModule,
    MatRippleModule,
  ],
  declarations: [
    SearchComponent,
  ],
})
export class MaterialModule {};

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    MaterialModule,
    BrowserModule,
    BrowserAnimationsModule,
    FormsModule,
    HttpModule,
    HttpClientModule,
  ],
  providers: [
    YahooService,
  ],
  bootstrap: [
    AppComponent,
  ],
  schemas: [
    CUSTOM_ELEMENTS_SCHEMA,
  ],
})
export class AppModule { }

search.component.html

<mat-form-field>
   <input matInput placeholder="Simple placeholder" required>
</mat-form-field>

search.component.ts

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from '@angular/forms';

@Component({
  selector: 'app-search',
  templateUrl: './search.component.html',
  styleUrls: ['./search.component.css']
})
export class SearchComponent implements OnInit {

  options: FormGroup;

  constructor(fb: FormBuilder) {
    this.options = fb.group({
      floatLabel: 'never',
    });
  }

  ngOnInit() {
  }

}

package.json

{
  "name": "forecast",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular-devkit/schematics": "0.0.40",
    "@angular/animations": "^5.1.3",
    "@angular/cdk": "^5.0.3",
    "@angular/common": "^5.1.3",
    "@angular/compiler": "^5.1.3",
    "@angular/core": "^5.1.3",
    "@angular/forms": "^5.1.3",
    "@angular/http": "^5.1.3",
    "@angular/material": "^5.0.3",
    "@angular/platform-browser": "^5.1.3",
    "@angular/platform-browser-dynamic": "^5.1.3",
    "@angular/router": "^5.1.3",
    "axios": "^0.17.1",
    "body-parser": "^1.18.2",
    "core-js": "^2.5.3",
    "express": "^4.16.2",
    "node-sass": "^4.7.2",
    "nodemon": "^1.14.7",
    "q": "^1.5.1",
    "rxjs": "^5.5.6",
    "zone.js": "^0.8.4"
  },
  "devDependencies": {
    "@angular/cli": "^1.6.3",
    "@angular/compiler-cli": "^5.1.3",
    "@types/jasmine": "2.5.38",
    "@types/node": "~6.0.60",
    "codelyzer": "~2.0.0",
    "jasmine-core": "~2.5.2",
    "jasmine-spec-reporter": "~3.2.0",
    "karma": "~1.4.1",
    "karma-chrome-launcher": "~2.0.0",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^0.2.0",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.0",
    "ts-node": "~2.0.0",
    "tslint": "~4.5.0",
    "typescript": "~2.4.0"
  }
}

推荐答案

你只是在你的 NgModule 中导出它，你也需要导入它

You're only exporting it in your NgModule, you need to import it too

@NgModule({
  imports: [
    MatButtonModule,
    MatFormFieldModule,
    MatInputModule,
    MatRippleModule,
 ]
  exports: [
    MatButtonModule,
    MatFormFieldModule,
    MatInputModule,
    MatRippleModule,
  ],
  declarations: [
    SearchComponent,
  ],
})export class MaterialModule {};

更好

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

@NgModule({
  imports: [...modules],
  exports: [...modules]
  ,
})export class MaterialModule {};

更新

在导入所有 Angular 依赖项之前，您正在根据 Angular Material 声明组件 (SearchComponent)

update

You're declaring component (SearchComponent) depending on Angular Material before all Angular dependency are imported

喜欢BrowserAnimationsModule

尝试将其移动到 MaterialModule 或之前

Try moving it to MaterialModule, or before it

这篇关于'mat-form-field' 不是已知元素 - Angular 5 &材料2的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！