How to perform change detection on div resizing

You can add a directive to the div and implement lifecycle hook ngDoCheck() to perform your own change detection logic. You'll need to inject ElementRef:

constructor(private _elRef:ElementRef) {}ngDoCheck() {   // use ElementRef to examine the div property of interest

If the div is inside a component template, add a local template variable

<div #myDiv ...>

Then use @ViewChild() to get a reference to the div and implement lifecycle hook ngDoCheck() or ngAfterViewChecked() to perform your own change detection logic.

@ViewChild('myDiv') theDiv:ElementRef;ngAfterViewChecked() {   // use this.theDiv to examine the div property of interest

Note that ngDoCheck() and ngAfterViewChecked() will be called every time change detection runs. See also the dev guide Lifecycle Hooks.

I had the same problem so I used the lightweight library called Angular-Resize-Event

https://www.npmjs.com/package/angular-resize-event

<div (resized)="onResized($event)"></div>

After installing it just add this output event to any div which you want to check for size changes.

I have tried the correct answer but the refresh rate wasn't very accurate, So I looked for another solution.

Here it is

// Directive@Directive({  selector: '[resize-detector]',})public constructor(public element: ElementRef<HTMLElement>) {}public ngOnInit(): void {// Call detectResize as whe the element inits the windows resize event most likely won't trigger  this.detectResize();}// if you need the windowDimensions add ", [$event]" to @HostListener and pass event to detectResize(event)@HostListener('window:resize') public detectResize(): void {  console.log(element.nativeElement.offsetWidth);  console.log(element.nativeElement.offsetHeight);  // Do you magic here ...}

Then you can use it in any element like:

<app-component resize-detector></app-component>