[英]How to render ng-template dynamically with Template Reference in Angular
我尝试了这个问题中的示例Dynamic ngTemplateOutlet value但仍然没有成功。
我想根据用户选择的选项动态显示ng-template
表单。
我在我的 component.ts 中定义了全局变量和 3 个 forms 及其模板引用
@ViewChild('formA', {static: false}) formAref: TemplateRef<any>;
formA = new UserForm('formA', 'Mus Mauris Form', this.formAref);
@ViewChild('formB', {static: true}) formBref: TemplateRef<any>;
formB = new UserForm('formB', 'Vitae Purus Faucibus Form ', this.formBref);
@ViewChild('formC', {static: true}) formCref: TemplateRef<any>;
formC = new UserForm('formC', 'Aliquet Nec Form', this.formCref);
selectedForm: TemplateRef<any>;
totalForms: UserForm[] = [];
其中 UserForm 定义为
interface UserFormInterface {
id: string;
display: boolean;
submitFunc: Function;
}
class UserForm implements UserFormInterface {
id: string;
form_name: string;
display: boolean;
submitFunc: Function;
reference: TemplateRef<any>;
constructor(id: string, form_name: string, reference: TemplateRef<any>) {
this.id = id;
this.form_name = form_name;
this.reference = reference;
}
}
在我的 HTML 模板中,我有以下内容
<div id="inner-form-dashboard" class="row">
<div id="form-list" class="col-4">
<div
*ngFor="let form of totalForms"
class="form-item d-flex flex-column justify-content-around align-items-center">
<div class="form-link" (click)="showForm(form)">{{form.form_name}}</div>
</div>
</div>
<div id="form-container" class="col-8 d-flex flex-column justify-content-between">
<div *ngFor="let form of totalForms">
<ng-container *ngIf="form.display" style="display: block;">
{{form.id}}
<div
*ngTemplateOutlet='selectedForm'>
</div>
</ng-container>
</div>
</div>
</div>
<ng-template #formA>
<form>
<div class="form-group">
<label for="exampleFormControlInput1">Email address</label>
<input type="email" class="form-control" id="exampleFormControlInput1" placeholder="name@example.com">
</div>
<div class="form-group">
<label for="exampleFormControlSelect1">Example select</label>
<select class="form-control" id="exampleFormControlSelect1">
<option>1</option>
<option>2</option>
<option>3</option>
<option>4</option>
<option>5</option>
</select>
</div>
<div class="form-group">
<label for="exampleFormControlTextarea1">Example textarea</label>
<textarea class="form-control" id="exampleFormControlTextarea1" rows="3"></textarea>
</div>
</form>
</ng-template>
第一列col-4
将根据左侧单击的项目确定在第二列col-8
上显示哪个表单。
当我点击左侧项目时,我可以看到form.id
显示在右侧,这意味着forms和ngFor
的选择工作正常,但是,在线模板*ngTemplateOutlet='selectedForm'>
不显示。
我的组件中的功能看起来像这样
showForm(form: UserForm): void {
this.totalForms.forEach(f => f.display = false);
form.display = true;
this.selectedForm = form.reference;
console.log(form);
console.log('selected', this.selectedForm);
}
问题的原因是您过早地尝试使用模板引用。 最早可以使用{ static: true }
的@ViewChild
属性是在ngOnInit生命周期钩子中:
ngOnInit() {
this.formA = new UserForm('formA', 'Mus Mauris Form', this.formAref);
this.formB = new UserForm('formB', 'Vitae Purus Faucibus Form ', this.formBref);
this.formC = new UserForm('formC', 'Aliquet Nec Form', this.formCref);
this.totalForms.push(this.formA, this.formB, this.formC);
}
当使用{ static: false }
时, @ViewChild
属性可用的最早是在ngAfterViewInit生命周期钩子中。
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