根据( bool )类变量的值,我希望我的 ng-content
要么包装在 div 中,要么不包装在 div 中(即 div 甚至不应该是在 DOM 中)...最好的方法是什么?我有一个Plunker试图做到这一点,以我认为是最明显的方式,使用 ngIf ..但它不起作用...它仅显示其中一个 bool 值的内容,而不显示另一个 bool 值的内容
请帮忙 谢谢!
http://plnkr.co/edit/omqLK0mKUIzqkkR3lQh8
@Component({
selector: 'my-component',
template: `
<div *ngIf="insideRedDiv" style="display: inline; border: 1px red solid">
<ng-content *ngIf="insideRedDiv" ></ng-content>
</div>
<ng-content *ngIf="!insideRedDiv"></ng-content>
`,
})
export class MyComponent {
insideRedDiv: boolean = true;
}
@Component({
template: `
<my-component> ... "Here is the Content" ... </my-component>
`
})
export class App {}
最佳答案
Angular ^4
作为解决方法,我可以为您提供以下解决方案:
<div *ngIf="insideRedDiv; else elseTpl" style="display: inline; border: 1px red solid">
<ng-container *ngTemplateOutlet="elseTpl"></ng-container>
</div>
<ng-template #elseTpl><ng-content></ng-content> </ng-template>
<强> Plunker Example angular v4
Angular <4
在这里您可以创建专用指令来执行相同的操作:
<div *ngIf="insideRedDiv; else elseTpl" style="display: inline; border: 1px red solid">
<ng-container *ngTemplateOutlet="elseTpl"></ng-container>
</div>
<template #elseTpl><ng-content></ng-content></template>
<强> Plunker Example
ngIf4.ts
class NgIfContext { public $implicit: any = null; }
@Directive({ selector: '[ngIf4]' })
export class NgIf4 {
private context: NgIfContext = new NgIfContext();
private elseTemplateRef: TemplateRef<NgIfContext>;
private elseViewRef: EmbeddedViewRef<NgIfContext>;
private viewRef: EmbeddedViewRef<NgIfContext>;
constructor(private viewContainer: ViewContainerRef, private templateRef: TemplateRef<NgIfContext>) { }
@Input()
set ngIf4(condition: any) {
this.context.$implicit = condition;
this._updateView();
}
@Input()
set ngIf4Else(templateRef: TemplateRef<NgIfContext>) {
this.elseTemplateRef = templateRef;
this.elseViewRef = null;
this._updateView();
}
private _updateView() {
if (this.context.$implicit) {
this.viewContainer.clear();
this.elseViewRef = null;
if (this.templateRef) {
this.viewRef = this.viewContainer.createEmbeddedView(this.templateRef, this.context);
}
} else {
if (this.elseViewRef) return;
this.viewContainer.clear();
this.viewRef = null;
if (this.elseTemplateRef) {
this.elseViewRef = this.viewContainer.createEmbeddedView(this.elseTemplateRef, this.context);
}
}
}
}
关于angular - 如何有条件地将 div 包裹在 ng-content 周围,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47639034/