如何延迟在 CDK overlay 中打开?

How to delay opening in CDK overlay?

我正在使用 CDK 覆盖在用户将鼠标悬停在列表项上时显示 "popover"。我目前在 mouseenter 事件触发时打开弹出窗口。

我的代码:

//component.html
<mat-list-item *ngFor="let item of itemList" (mouseenter)="showItemDetail(item)">
    {{item.display}}
</mat-list-item>




//component.ts
showItemDetail(item: IItemDto, event: MouseEvent) {
        this.hideItemDetail(); // Closes any open overlays
        this.itemDetailOverlayRef = this.itemDetailOverlayService.open(item);
}



//itemDetailOverlayService.ts
open(item: IItemDto) {

        // Returns an OverlayRef (which is a PortalHost)

        const overlayRef = this.createOverlay(item);
        const dialogRef = new ItemDetailOverlayRef(overlayRef);
        // Create ComponentPortal that can be attached to a PortalHost
        const itemDetailPortal = new ComponentPortal(ItemDetailOverlayComponent);
        const componentInstance = this.attachDialogContainer(overlayRef, item, dialogRef);
        // Attach ComponentPortal to PortalHost
        return dialogRef;
}


private attachDialogContainer(overlayRef: OverlayRef, item: IItemDto, dialogRef: ItemDetailOverlayRef) {
        const injector = this.createInjector(item, dialogRef);
        const containerPortal = new ComponentPortal(ItemDetailOverlayComponent, null, injector);
        const containerRef: ComponentRef<ItemDetailOverlayComponent> = overlayRef.attach(containerPortal);
        return containerRef.instance;
}

请注意,我的叠加层依赖于列表项数据中的数据。

如何延迟showItemDetail() 2 秒后才打开叠加层?请记住,一次只能打开一个弹出窗口。

setTimeout() 显然不会起作用,因为如果用户将鼠标拖过项目列表,将打开多个弹出窗口。

已通过使用 css 创建延迟效果时立即打开叠加层解决 animation/keyframes:

.container {
    animation: fadeIn 1.5s linear;
}

@keyframes fadeIn {
    0% {
        opacity: 0;
    }

    75% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}