Angular [disabled]="MyBoolean" not working

I have some inputs (Checkboxes) and I want them to be disabled if my Booleans are true. But its not working... The funny thing is the submit button works just fine and thats the same method...

myComponent.html

          <form [formGroup]="BetreuungsoptionForm" (ngSubmit)="onSubmit()">
            <label *ngIf="!eingetragen" for="art">Art</label>
            <select *ngIf="!eingetragen" formControlName="art" id="art" class="form-control" [(ngModel)]="Art" required >
              <option value="festeAnmeldung">feste Anmeldung</option>
              <option value="flexibleAnmeldung">flexible Anmeldung</option>
            </select>
            <label for="datum">Beginn Datum</label>
            <input formControlName="datum" type="date" id="datum" class="form-control" required>
            <label *ngIf="(Art == 'festeAnmeldung')" for="montag">Montag</label>
            <input *ngIf="(Art == 'festeAnmeldung')" formControlName="montag" [disabled]="montag" type="checkbox" id="montag" class="form-control wochentag">
            <label *ngIf="(Art == 'festeAnmeldung')" for="dienstag">Dienstag</label>
            <input *ngIf="(Art == 'festeAnmeldung')" formControlName="dienstag" [disabled]="dienstag" type="checkbox" id="dienstag" class="form-control wochentag">
            <label *ngIf="(Art == 'festeAnmeldung')" for="mittwoch">Mittwoch</label>
            <input *ngIf="(Art == 'festeAnmeldung')" formControlName="mittwoch" [disabled]="mittwoch" type="checkbox" id="mittwoch" class="form-control wochentag">
            <label *ngIf="(Art == 'festeAnmeldung')" for="donnerstag">Donnerstag</label>
            <input *ngIf="(Art == 'festeAnmeldung')" formControlName="donnerstag" [disabled]="donnerstag" type="checkbox" id="donnerstag" class="form-control wochentag">
            <label *ngIf="(Art == 'festeAnmeldung')" for="freitag">Freitag</label>
            <input *ngIf="(Art == 'festeAnmeldung' )" formControlName="freitag" [disabled]="freitag" type="checkbox" id="freitag" class="form-control wochentag">
        <button type="submit" [disabled]="!BetreuungsoptionForm.valid" class ="btn btn-primary">Speichern</button>
        <button type="button" (click)="OnBetreuungsoptionInfos()" class ="btn btn-success">weitere Informationen</button>
        <button type="button" *ngIf="!gekuendigt" (click)="OnBetreuungsoptionLoeschen()" class ="btn btn-danger">Kündigen</button>
      </form>

myComponent.ts

        this.BetreuungsoptionForm = new FormGroup
        ({
          art: new FormControl(),
          datum: new FormControl(this.BetreuungsoptionenKindRef[d].Beginn.toString().substring(0,10)),
          montag: new FormControl(this.BetreuungsoptionenKindRef[d].Montag),
          dienstag: new FormControl(this.BetreuungsoptionenKindRef[d].Dienstag),
          mittwoch: new FormControl(this.BetreuungsoptionenKindRef[d].Mittwoch),
          donnerstag: new FormControl(this.BetreuungsoptionenKindRef[d].Donnerstag),
          freitag: new FormControl(this.BetreuungsoptionenKindRef[d].Freitag)
        })
          if(this.BetreuungsoptionenKindRef.Montag)
          {
            this.montag = true;
          }
          if(this.BetreuungsoptionenKindRef.Dienstag)
          {
            this.dienstag = true;
          }
          if(this.BetreuungsoptionenKindRef.Mittwoch)
          {
            this.mittwoch = true;
          }
          if(this.BetreuungsoptionenKindRef.Donnerstag)
          {
            this.donnerstag = true;
          }
          if(this.BetreuungsoptionenKindRef.Freitag)
          {
            this.freitag = true;
          }

Try [attr.disabled]="freitag? true : null" or [attr.readonly]="freitag" instead.

You are able to use attributes like [class.btn-lg]="someValue" in a similar way.

Your textbox works because of this:

> The disabled attribute is another peculiar example. A button's > disabled property is false by default so the button is enabled. When > you add the disabled attribute, its presence alone initializes the > button's disabled property to true so the button is disabled. > > Adding and removing the disabled attribute disables and enables the > button. The value of the attribute is irrelevant, which is why you > cannot enable a button by writing <button disabled="false">Still Disabled</button>.

from https://angular.io/guide/template-syntax

Try this, trust me it's working..

<input [disabled]="isLoading ? true : null" />

Use null instead of false

Reactive forms don't support native 'disabled' attribute. If you want them to work the way you wanted, try exploring this : https://netbasal.com/disabling-form-controls-when-working-with-reactive-forms-in-angular-549dd7b42110

Also see Angular reactive forms doc to do something like this in form control.

Eg: new FormControl({value:'tom', disabled: true})

Reactive Forms:

.html file:

<textarea class="form-control" rows="4" formControlName="message" [readonly]="disableMessage"></textarea>

.ts file:

disableMessage = true;

If you are using bootstrap and apply any background colour using class, just remove it. it will work.

        <button type="submit" class='**bg-primary** text-left form-control w-auto text-white mt-4' [disabled]="manageUsers.invalid">Submit</button>

Please remove "bg-primary" in class field. then it will work.

in my case, I was wrongly using FormControl, expecting that it's having the control name like [formControl]="CtrlName" when I removed it, disabled working fine now.

Here is the disabled tag that worked for me

[disabled]="isDisabledVariable"

Note: If you are using an Angular Material button, a good example is:

<button mat-button [disabled]="condition">Button</button>

This works since the library defines an input property for passing in a "disabled" value, i.e. @Input('disabled').

For me none of the above worked, including the below

[disabled]="!enableDelete">

What worked for me was

[disabled]="enableSave == 'false'">