Angular 为什么ContentChild是未定义的?
我有两个组件Angular 为什么ContentChild是未定义的?,angular,Angular,我有两个组件FormComponent和Test1Component Test1Component使用ng内容显示FormComponent FormComponent.ts import { Component, Input, Output, EventEmitter } from '@angular/core'; @Component({ selector: 'app-form', template:` <div class="panel panel-defaul
FormComponent
和Test1Component
Test1Component
使用ng内容
显示FormComponent
FormComponent.ts
import { Component, Input, Output, EventEmitter } from '@angular/core';
@Component({
selector: 'app-form',
template:`
<div class="panel panel-default fcs-form">
<div class="panel-header form-header">
{{headerTitle}}
</div>
<div class="panel-body form-body">
<ng-content select="[form-body]"></ng-content>
</div>
<div class="panel-footer text-center form-footer">
<button class="btn btn-primary">{{resetBtnText}}</button>
<button class="btn btn-primary" (click)="saveForm()"> {{saveBtnText}} </button>
<button class="btn btn-primary">{{addBtnText}}</button>
</div>
</div>
`
})
export class FormComponent{
@Input() headerTitle:string = "Header Title";
@Input() saveBtnText:string = "Save";
@Input() resetBtnText:string = "Reset";
@Input() addBtnText:string = "Add";
@Output() save:EventEmitter<any> = new EventEmitter();
constructor(){}
saveForm(e: any){
this.save.emit("save");
console.log("FormComponent save");
}
}
import { Component, Inject, OnInit, ContentChild } from '@angular/core';
import { FormGroup, FormBuilder } from '@angular/forms';
import { FormComponent } from './form.component';
@Component({
selector: 'app-test1',
template: `
<app-form headerTitle="my header" (save)="saveForm(complexForm.value, $event)">
<div form-body>
<div class="jumbotron">
<form [formGroup]="complexForm" (ngSubmit)="submitForm(complexForm.value)">
<div class="form-group">
<label>First Name:</label>
<input class="form-control" type="text" placeholder="John" [formControl]="complexForm.controls['firstName']">
</div>
</form>
</div>
</div>
</app-form>
`
})
export class Test1Component {
@ContentChild(FormComponent) contentChildForm: FormComponent;
complexForm : FormGroup;
constructor(private fb: FormBuilder){
this.complexForm = fb.group({
'firstName' : "",
'lastName': "",
'gender' : "Female",
'hiking' : false,
'running' : false,
'swimming' : false
});
}
saveForm(){
console.log(this.contentChildForm);
debugger;
console.log("Test1Component save");
return true;
}
}
从'@angular/core'导入{Component,Input,Output,EventEmitter};
@组成部分({
选择器:“应用程序窗体”,
模板:`
{{headerTitle}}
{{resetBtnText}
{{saveBtnText}
{{addBtnText}
`
})
导出类FormComponent{
@Input()标题:string=“标题标题”;
@Input()saveBtnText:string=“Save”;
@Input()resetBtnText:string=“Reset”;
@Input()addBtnText:string=“Add”;
@Output()save:EventEmitter,请打开控制台查看日志。在您的情况下,我将使用@ViewChild
,因为我在您的Test1Component
中没有看到任何类型为FormComponent
的可投影节点
事实上,我认为这是正确的答案。了解何时使用@ViewChild
和@ContentChild
:@SrAxi可以让事情在概念上清晰易懂follow@yurzui在阅读了一些文章之后,使用ViewChild引用将数据传递给孩子们,或者使用Input decorator,这是明智的做法吗,我的印象是,家长应该使用输入向孩子传递数据,孩子应该使用事件向孩子传递数据Parent@FlyingGambit我建议您阅读以下内容:。这将对您有很大帮助。顺便说一句,如果您计划将相同的数据传递给其他组件,请选择共享服务。
。干杯!