Angular 4中*ngFor无法正常工作求助

Hey there, I get it—figuring out Angular modules can be tricky when you're just starting out! It looks like your provided app.module.ts code is truncated (the ContactsComponent import cuts off), but let's go through some common checks that might fix your issue:

• Double-check component file paths: The import for ContactsComponent is incomplete. Make sure the path matches the actual file name (e.g., if your component file is named contacts.component.ts, the import should be import { ContactsComponent } from './contacts/contacts.component';). Typos in file names or paths are super common when starting out!

• Ensure components are declared in the module: Even if you've imported a component, Angular won't recognize it unless it's added to the declarations array in your AppModule. Here's how that should look:

  @NgModule({
    declarations: [
      AppComponent,
      ContactsComponent // This line must be present!
    ],
    imports: [
      BrowserModule,
      FormsModule,
      HttpModule,
      CommonModule
    ],
    providers: [],
    bootstrap: [AppComponent]
  })
  export class AppModule { }
  

• Check for outdated modules: If you're using a newer version of Angular (4.3+), note that HttpModule has been replaced with HttpClientModule from @angular/common/http. If that's the case, swap out HttpModule with HttpClientModule in your imports.

• Clear your app cache and rebuild: Sometimes cached build files can cause weird issues. Run ng clean in your terminal, then ng serve again to rebuild everything from scratch.

• Look for specific error messages: Open your browser's developer tools (press F12) and check the Console tab. The error messages there will give you exact details about what's going wrong—like if a component isn't declared, or a module is missing.

If you can share the complete app.module.ts code and any error messages you're seeing, I can help you pinpoint the exact problem!

内容的提问来源于stack exchange，提问作者P K