Angular ngClass and click event for toggling class

问题:

In Angular, I would like to use ngClass and click event to toggle class. I looked through online but some are angular1 and there isn't any clear instruction or example. Any help will be much appreciated!

In HTML, I have the following:

<div class="my_class" (click)="clickEvent($event)"  ngClass="{'active': toggle}">                
     Some content
</div>

In .ts:

 clickEvent(event){
    //Haven't really got far
    var targetEle = event.srcElement.attributes.class;        
 }     

回答1:

This Should work for you:

<div class="my_class" (click)="clickEvent()"  
    [ngClass]="status ? 'success' : 'danger'">                
     Some content
</div>

status: boolean = false;
clickEvent(){
    this.status = !this.status;       
}

回答2:

Instead of having to create a function in the ts file you can toggle a variable from the template itself. You can then use the variable to apply a specific class to the element. Like so-

<div (click)="status=!status"  
    [ngClass]="status ? 'success' : 'danger'">                
     Some content
</div>

So when status is true the class success is applied. When it is false danger class is applied.

This will work without any additional code in the ts file.

回答3:

ngClass should be wrapped in square brackets as this is a property binding. Try this:

<div class="my_class" (click)="clickEvent($event)"  [ngClass]="{'active': toggle}">                
     Some content
</div>

In your component:

     //define the toogle property
     private toggle : boolean = false;

    //define your method
    clickEvent(event){
       //if you just want to toggle the class; change toggle variable.
       this.toggle != this.toggle;       
    }

Hope that helps.

回答4:

Angular6 using the renderer2 without any variables and a clean template:

template:

<div (click)="toggleClass($event,'testClass')"></div>

in ts:

toggleClass(event: any, class: string) {
  const hasClass = event.target.classList.contains(class);

  if(hasClass) {
    this.renderer.removeClass(event.target, class);
  } else {
    this.renderer.addClass(event.target, class);
  }
}

One could put this in a directive too ;)

回答5:

If you want to toggle text with a toggle button.

HTMLfile which is using bootstrap:

<input class="btn" (click)="muteStream()"  type="button"
          [ngClass]="status ? 'btn-success' : 'btn-danger'" 
          [value]="status ? 'unmute' : 'mute'"/>

TS file:

muteStream() {
   this.status = !this.status;
}