*ngIf hide some content on mobile screen, Angular

问题:

I have:

showHide: false;

<div *ngIf="showHide">
  Content
</div>

<button (click)="showHide = !showMap">
  Button visited only max-width: 768px
</button>

In MAX-width: 768px, I have a button. On MIN-width: 768px button is hide. When I click on the button - it show a DIV. It work fine.

BUT

How to make *ngIf work only when MAX-width: 768px?

max-height: 768px

• button is display: block
• DIV is display: none (but when I click on the button = display:
  block)

min-height: 768px:

• button is display: none
• DIV is display: block

At the moment when I resize from example 500px to 1000px: It depends on button I pressed

回答1:

You can use window.screen.width. Example:

ngOnInit() {
  if (window.screen.width === 360) { // 768px portrait
    this.mobile = true;
  }
}

Html:

<button *ngIf="mobile" (click)="showHide = !showMap"></button>

回答2:

For future me or others if you need a solution that monitors the screen size and are using Observables/rxjs then this solution works:

ngOnInit(): void {
  // Checks if screen size is less than 1024 pixels
  const checkScreenSize = () => document.body.offsetWidth < 1024;

  // Create observable from window resize event throttled so only fires every 500ms
  const screenSizeChanged$ = Observable.fromEvent(window, 'resize').throttleTime(500).map(checkScreenSize);

  // Start off with the initial value use the isScreenSmall$ | async in the
  // view to get both the original value and the new value after resize.
  this.isScreenSmall$ = screenSizeChanged$.pipe(startWith(checkScreenSize()))
}

回答3:

Thought I would add this to the question as I found in this particular situation @angular/flex-layout to be very helpful. https://github.com/angular/flex-layout.

In particular you might be interested in the fxHide feature: https://github.com/angular/flex-layout/wiki/fxHide-API but this package makes working with a responsive application much easier in my opinion.

You can show or hide content like so.

Doesnt show when 'small' or greater than 'medium' resolutions:

<div fxShow.sm="false" fxShow.gt-md="false" fxShow="true" ></div>

Only hides when at medium resolution

<div fxShow fxHide.md ></div>

The breakpoints can be custom but they have default ones already set.

回答4:

Just came across this answer and I wanted something that worked responsively as well as on-resize. I set 992px as the breakpoint because I'm also using bootstrap lg breakpoints concurrently.

export class TestComponent implements OnInit {

  constructor() { }

  isMobile = false;
  getIsMobile(): boolean {
    const w = document.documentElement.clientWidth;
    const breakpoint = 992;
    console.log(w);
    if (w < breakpoint) {
      return true;
    } else {
      return false;
    }
  }

  ngOnInit() {
    this.isMobile = this.getIsMobile();
    window.onresize = () => {
      this.isMobile = this.getIsMobile();
    };
  }
}

Then in the HTML

<div *ngIf="isMobile === true>Some mobile element!</div>

回答5:

The least lines solution:

In your TS file:

public isMobileLayout = false;
ngOnInit() {
  window.onresize = () => this.isMobileLayout = window.innerWidth <= 991;
}

In HTML template:

<div *ngIf="isMobileLayout">This is visible only on mobile</div>

Edit: Also, you can detect mobile using the following code:

public get isMobileAgent() {
    const agent = navigator.userAgent || navigator.vendor || (window as any).opera;
    // tslint:disable-next-line:max-line-length
    return (/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows ce|xda|xiino/i.test(agent) || /1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(agent.substr(0, 4)));
}

This might be helpful to initialize isMobileLayout value before any resize happens:

public isMobileLayout = isMobileAgent;

Or:

<div *ngIf="isMobileLayout || isMobileAgent">This is visible only on mobile</div>

回答6:

This works when you resize the browser window

@HostListener("window:resize", [])
  onResize() {
    var width = window.innerWidth;
    if (width < 992) {
      this.mobile = true;
    } else {
      this.mobile = false;
    }
  }

回答7:

Use the below code into the OnInit()

inMobile:boolean = false
ngOnInit() {
  if (window.screen.width === 360) {
    this.isMobile = true;
  }
}

by using above code we can put two css; based on desktop and mobile:-

<button *ngIf="mobile">Close</button>

or

<button [class.button]="!isMobile" [class.button-mobile]="isMobile">Close</button>

CSS:

.button{
margin-left:100px;
}
.button-mobile{
margin-left:50px;
}