Angular AppModule导入MatDatepickerModule报无法静态确定值错误

这个静态解析错误是MatDatepickerModule的导入路径写错导致的：你当前从@angular/material/input路径导入该模块，但这个包下根本没有导出MatDatepickerModule，Angular编译时无法拿到合法的模块引用，就会抛出「值无法静态确定」的报错。
补充：@angular/material/input包下导出的是MatInputModule，和日期选择器模块无关。
另外你贴的源码还存在基础语法问题：漏写了@NgModule()装饰器开头，也没有写declarations组件声明数组，直接把imports数组暴露在外层，这也会触发编译错误。

• 先修正导入路径，从正确的包引入MatDatepickerModule：

  // 错误写法
  // import {MatDatepickerModule} from '@angular/material/input';
  // 正确写法
  import { MatDatepickerModule } from '@angular/material/datepicker';
  

• 补全日期选择器的依赖模块。Angular Material的日期选择器不能单独运行，必须搭配输入框模块、日期适配器模块使用，需要额外引入：
  • MatInputModule（来自@angular/material/input）
  • MatNativeDateModule（原生日期适配，来自@angular/material/core）
• 补全@NgModule装饰器的完整结构，把所有自定义组件加入declarations数组。

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import {HttpClientModule} from '@angular/common/http';
import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { FormsModule } from '@angular/forms';
import { FrontpageComponent } from './frontpage/frontpage.component';
import { AdministratorComponent } from './administrator/administrator.component';
import { AdminCustomerComponent } from './admin-customer/admin-customer.component';
import { Ng2SearchPipeModule } from 'ng2-search-filter';
import { DatePipe } from '@angular/common';
import { CategoryComponent } from './category/category.component';
import { BookComponent } from './book/book.component';
import { LoginComponent } from './login/login.component';
import { ContactComponent } from './contact/contact.component';
import { CategoryDetailsComponent } from './category-details/category-details.component';
import { BookDetailsComponent } from './book-details/book-details.component';
import { LoanComponent } from './loan/loan.component';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MatDatepickerModule } from '@angular/material/datepicker';
import { MatInputModule } from '@angular/material/input';
import { MatNativeDateModule } from '@angular/material/core';

@NgModule({
  declarations: [
    AppComponent,
    FrontpageComponent,
    AdministratorComponent,
    AdminCustomerComponent,
    CategoryComponent,
    BookComponent,
    LoginComponent,
    ContactComponent,
    CategoryDetailsComponent,
    BookDetailsComponent,
    LoanComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    HttpClientModule,
    FormsModule,
    Ng2SearchPipeModule,
    BrowserAnimationsModule,
    MatInputModule,
    MatDatepickerModule,
    MatNativeDateModule
  ],
  providers: [DatePipe],
  bootstrap: [AppComponent]
})
export class AppModule { }

替换完文件后重新执行ng serve启动项目，报错就会消失。

内容的提问来源于stack exchange，提问作者BILAL