Ich habe eine Komponentenliste und ihr Kind (Komponentenelement). Ich versuche, Informationen von Liste zu Element zu übergeben, aber es scheint, Datenbindung funktioniert nicht, weil das Objekt null ist, auch wenn ich (hoffe) richtig initialisiert wurde.Fehler während der Datenbindung: Eigenschaft ist null
Dies ist die Liste Komponente mit einer eigenen Vorlage:
import { Component, OnInit, Output, EventEmitter } from '@angular/core';
import { Recipe } from '../recipe';
import { RecipeItemComponent } from './recipe-item.component';
@Component({
selector: 'app-recipe-list',
templateUrl: './recipe-list.component.html',
styles: []
})
export class RecipeListComponent implements OnInit {
@Output() recipeSelected = new EventEmitter<Recipe>();
recipes: Recipe[] = [];
public recipe: Recipe;
constructor() {
this.recipe = new Recipe('Dummy', 'Dummy', 'http://thumbs1.ebaystatic.com/d/l225/m/mfXELL6zPWJE4OC0agiXMZw.jpg');
}
ngOnInit() {
}
onSelected(recipe: Recipe) {
this.recipeSelected.emit(recipe);
}
}
<div class="row">
<div class="col-xs-12">
<a class="btn btn-success">New Recipe</a>
</div>
</div>
<div class="row">
<div class="col-xs-12">
<ul class="list-group">
<app-recipe-item> [recipe]="recipe" (click)="onSelected(recipe)"></app-recipe-item>
</ul>
</div>
</div>
Und hier die Komponente Artikel:
import { Component, OnInit, Input } from '@angular/core';
import { Recipe } from '../recipe';
@Component({
selector: 'app-recipe-item',
templateUrl: './recipe-item.component.html',
styles: []
})
export class RecipeItemComponent implements OnInit {
@Input() recipe: Recipe;
recipeId: number;
constructor() {
}
ngOnInit() {
}
}
<a href="#" class="list-group-item clearfix">
<div class="pull-left">
<h4 class="list-group-item-heading">{{name}}</h4>
<p class="list-group-item-text">{{description}}</p>
</div>
<span class="pull-right">
<img class="img-responsive"
src="{{imagePath}}"
style="max-height: 50px;"/>
</span>
</a>
Der Fehler:
Unhandled Promise rejection: Error in ./RecipeItemComponent class RecipeItemComponent - inline template:2:40 caused by: Cannot read property 'name' of undefined ; Zone: <root> ; Task: Promise.then ; Value:
ViewWrappedError
Error: Error in ./RecipeItemComponent class RecipeItemComponent - inline template:2:40 caused by: Cannot read property 'name' of undefined
at ViewWrappedError.ZoneAwareError (http://localhost:4200/polyfills.bundle.js:6880:33)
at ViewWrappedError.BaseError [as constructor] (http://localhost:4200/vendor.bundle.js:24986:16)
at ViewWrappedError.WrappedError [as constructor] (http://localhost:4200/vendor.bundle.js:25051:16)
at new ViewWrappedError (http://localhost:4200/vendor.bundle.js:53759:16)
at CompiledTemplate.proxyViewClass.DebugAppView._rethrowWithContext (http://localhost:4200/vendor.bundle.js:72648:23)
at CompiledTemplate.proxyViewClass.DebugAppView.detectChanges (http://localhost:4200/vendor.bundle.js:72621:18)
at CompiledTemplate.proxyViewClass.AppView.internalDetectChanges (http://localhost:4200/vendor.bundle.js:72408:18)
at CompiledTemplate.proxyViewClass.View_RecipeListComponent0.detectChangesInternal (/AppModule/RecipeListComponent/component.ngfactory.js:96:20)
at CompiledTemplate.proxyViewClass.AppView.detectChanges (http://localhost:4200/vendor.bundle.js:72423:14)
at CompiledTemplate.proxyViewClass.DebugAppView.detectChanges (http://localhost:4200/vendor.bundle.js:72618:44)
at CompiledTemplate.proxyViewClass.AppView.internalDetectChanges (http://localhost:4200/vendor.bundle.js:72408:18)
at CompiledTemplate.proxyViewClass.View_RecipesComponent0.detectChangesInternal (/AppModule/RecipesComponent/component.ngfactory.js:83:19)
at CompiledTemplate.proxyViewClass.AppView.detectChanges (http://localhost:4200/vendor.bundle.js:72423:14)
at CompiledTemplate.proxyViewClass.DebugAppView.detectChanges (http://localhost:4200/vendor.bundle.js:72618:44)
at CompiledTemplate.proxyViewClass.AppView.internalDetectChanges (http://localhost:4200/vendor.bundle.js:72408:18)
Hier ist meine abgewinkelte Ausführung:
angular-cli: 1.0.0-beta.28.3
node: 7.6.0
os: win32 x64
@angular/common: 2.4.9
@angular/compiler: 2.4.9
@angular/core: 2.4.9
@angular/forms: 2.4.9
@angular/http: 2.4.9
@angular/platform-browser: 2.4.9
@angular/platform-browser-dynamic: 2.4.9
@angular/router: 3.4.9
@angular/compiler-cli: 2.4.9
Vielen Dank für einen Vorschlag.
Hinzugefügte Informationen:
Rezept Klassenobjekt:
export class Recipe {
constructor(public name: string, public description: string, public imagePath: string) {
}
}
'
{{rezept.name}}
'? –Kann Eigenschaft 'Name' von undefined nicht lesen, überprüfen Sie Ihre Variablendeklaration in 'RecipeItemComponent' –