Question

我的app.module

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';

import { AppComponent } from './app.component';
import { routing, appRoutingProviders} from './app.routing'
import { ProductSearchModule} from './productSearch/productSearch.module'

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    routing,
    ProductSearchModule
  ],
  providers: [appRoutingProviders],
  bootstrap: [AppComponent]
})
export class AppModule { }

我的productSearch.module

import {NgModule} from '@angular/core'
import {ProductSearchComponent} from './productSearch.component'

@NgModule({
    exports: [ProductSearchComponent],
    declarations: [ProductSearchComponent],

})

export class ProductSearchModule{}

我的productSearch组件

import { Component, Output } from '@angular/core'
import { Product} from '../shared/product'

@Component({
    selector: 'product-search',
    templateUrl: 'productSearch.component.html',
    styleUrls: ['productSearch.component.css'],

})

export class ProductSearchComponent{
    /**
     *
     */
    constructor() {
        var p1 = new Product;
        p1.name = "alkan";

        var p2 = new Product;
        p2.name = "alper";
        this.Products = [p1, p2];

    }

    Products: Product[]

    search(){

    }
}

productSearch.component.html文件

<li *ngFor="let item for Products">{{item.name}}</li>

如您所见，这是Angular的一个非常基本的例子。我只想打印每种产品的名称。

错误我得到了：

无法绑定到＆＃39; ngForFor＆＃39;因为它不是＆＃39; li＆＃39;
的已知属性

更新

组件构造函数更改为

var p1 = new Product();
p1.name = "alkan";

var p2 = new Product();
p2.name = "alper";
this.Products = [p1, p2];

和模板html更改为

<li *ngFor="let item of Products">{{item.name}}</li>

但我仍然得到错误：

Can't bind to 'ngForOf' since it isn't a known property of 'li'

Answer 1

我认为let item of Products文件中for不是productSearch.component.html。查看documentation

Answer 2

    var p1 = new Product();   //<----added ();
    p1.name = "alkan";

    var p2 = new Product();   //<----added ();
    p2.name = "alper";
    this.Products = [p1, p2];

     //<---replace for keyword by of keyword
    <li *ngFor="let item of Products">{{item.name}}</li>

<强>更新

您还需要添加 CommonModule ，如下所示，

import {NgModule} from '@angular/core';   
import {ProductSearchComponent} from './productSearch.component'

import {CommonModule} from '@angular/common';

@NgModule({
    imports: [CommonModule],                   //<====added
    exports: [ProductSearchComponent],
    declarations: [ProductSearchComponent],

})

Answer 3

*ngFor是一个驻留在Angular的CommonModule（来自@angular/common包）的指令。因此，请确保在您自己的模块中导入此模块，如下所示：

import { CommonModule } from '@angular/common';

@NgModule({
    imports: [CommonModule, ...],
    exports: [...],
    declarations: [...],
});

我喜欢做的是创建一个共享模块，它导入所有基本模块，如CommonModule等，然后重新导出它们。因此，当您导入共享模块时，您已经拥有了所有基本指令。

无法绑定到＆＃39; ngForFor＆＃39;因为它不是一个已知的属性，所以＆＃39; li＆＃39;

3 个答案: