Angular日期选择器引入moment后模块找不到及导入异常求助

问题描述 #

按照Angular日期选择器官方文档代码开发时，遭遇Moment导入相关错误。安装moment包后问题未解决，反而引发更多原有导入的错误。已尝试执行npm install --save @angular/core和npm install --save命令，错误仍存在。

相关代码 #

TypeScript代码 #

import {Component, ViewEncapsulation} from '@angular/core';
import {FormControl} from '@angular/forms';
import {MomentDateAdapter, MAT_MOMENT_DATE_ADAPTER_OPTIONS} from '@angular/material-moment-adapter';
import {DateAdapter, MAT_DATE_FORMATS, MAT_DATE_LOCALE} from '@angular/material/core';
import {MatDatepicker} from '@angular/material/datepicker';

// Depending on whether rollup is used, moment needs to be imported differently.
// Since Moment.js doesn't have a default export, we normally need to import using the `* as`
// syntax. However, rollup creates a synthetic default module and we thus need to import it using
// the `default as` syntax.
import * as _moment from 'moment';
// tslint:disable-next-line:no-duplicate-imports
import {default as _rollupMoment, Moment} from 'moment';

const moment = _rollupMoment || _moment;

// See the Moment.js docs for the meaning of these formats:
// https://momentjs.com/docs/#/displaying/format/
export const MY_FORMATS = {
  parse: {
    dateInput: 'MM/YYYY',
  },
  display: {
    dateInput: 'MM/YYYY',
    monthYearLabel: 'MMM YYYY',
    dateA11yLabel: 'LL',
    monthYearA11yLabel: 'MMMM YYYY',
  },
};

/** @title Datepicker emulating a Year and month picker */
@Component({
  selector: 'datepicker-views-selection-example',
  templateUrl: 'datepicker-views-selection-example.html',
  styleUrls: 'datepicker-views-selection-example.css',
  providers: [
    // `MomentDateAdapter` can be automatically provided by importing `MomentDateModule` in your
    // application's root module. We provide it at the component level here, due to limitations of
    // our example generation script.
    {
      provide: DateAdapter,
      useClass: MomentDateAdapter,
      deps: [MAT_DATE_LOCALE, MAT_MOMENT_DATE_ADAPTER_OPTIONS],
    },

    {provide: MAT_DATE_FORMATS, useValue: MY_FORMATS},
  ],
  encapsulation: ViewEncapsulation.None,
})
export class DatepickerViewsSelectionExample {
  date = new FormControl(moment());

  setMonthAndYear(normalizedMonthAndYear: Moment, datepicker: MatDatepicker<Moment>) {
    const ctrlValue = this.date.value!;
    ctrlValue.month(normalizedMonthAndYear.month());
    ctrlValue.year(normalizedMonthAndYear.year());
    this.date.setValue(ctrlValue);
    datepicker.close();
  }
}

HTML模板 #

<mat-form-field appearance="fill">
  <mat-label>Month and Year</mat-label>
  <input matInput [matDatepicker]="dp" [formControl]="date">
  <mat-hint>MM/YYYY</mat-hint>
  <mat-datepicker-toggle matIconSuffix [for]="dp"></mat-datepicker-toggle>
  <mat-datepicker #dp
                  startView="multi-year"
                  (monthSelected)="setMonthAndYear($event, dp)"
                  panelClass="example-month-picker">
  </mat-datepicker>
</mat-form-field>

错误截图 #

修复步骤 #

1. 安装正确的依赖包 #

确保同时安装moment及其类型定义，适配Angular版本：

npm install moment @types/moment --save

2. 简化Moment导入逻辑 #

将原有复杂的rollup兼容导入替换为标准导入方式，避免冲突：

// 替换原有moment导入部分
import * as moment from 'moment';
import { Moment } from 'moment';

同时删除const moment = _rollupMoment || _moment;这一行，直接使用导入的moment变量。

3. 配置TypeScript编译选项 #

在tsconfig.json的compilerOptions中添加以下配置，确保模块导入兼容：

{
  "compilerOptions": {
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true,
    "moduleResolution": "node"
  }
}

4. 清理缓存并重建项目 #

删除依赖缓存和锁定文件，重新安装后启动项目：

rm -rf node_modules package-lock.json
npm install
ng serve --open

5. 确认模块导入配置 #

在使用该组件的NgModule中，确保导入必要的Angular Material和表单模块：

import { MatDatepickerModule } from '@angular/material/datepicker';
import { MatMomentDateModule } from '@angular/material-moment-adapter';
import { ReactiveFormsModule } from '@angular/forms';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';

@NgModule({
  imports: [
    // ...其他模块
    ReactiveFormsModule,
    MatFormFieldModule,
    MatInputModule,
    MatDatepickerModule,
    MatMomentDateModule
  ]
})
export class YourFeatureModule { }

内容的提问来源于stack exchange，提问作者Mega