Question

我是角度5的新手，在这里我尝试根据条件禁用输入字段。

 <div *ngIf="isOTPFieldEnabled" class="email-field-width">
  <mat-form-field class="email-field-width">
   <mat-label>  Enter OTP</mat-label>
   <input [attr.disabled]="isDiableSignInOTPField" #OTP (click)="getOTP(OTP.value)" [formControl]="signInOTP"  maxlength="6" matInput required placeholder="OTP">
  <mat-hint [ngStyle]="{color: hintColor}">{{hintOTP}}</mat-hint>
 </mat-form-field>
 </div>

页面加载后，该div对用户不可见。一旦*ngIf="isOTPFieldEnabled"值满足 TRUE ，它将对用户可见。并且在 getOTP（）方法中验证了用户输入后，我想禁用此输入字段。

为此，我已设置[attr.disabled]，该功能可以正常使用，但出现标题中提到的错误。

详细错误：

ERROR Error: ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked. Previous value: 'mat-focused: true'. Current value: 'mat-focused: false'.
    at viewDebugError (core.js:7290)
    at expressionChangedAfterItHasBeenCheckedError (core.js:7278)
    at checkBindingNoChanges (core.js:7380)
    at checkNoChangesNodeDynamic (core.js:10263)
    at checkNoChangesNode (core.js:10233)
    at debugCheckNoChangesNode (core.js:10833)
    at debugCheckRenderNodeFn (core.js:10787)
    at Object.eval [as updateRenderer] (CheckoutComponent.html:159)
    at Object.debugUpdateRenderer [as updateRenderer] (core.js:10776)
    at checkNoChangesView (core.js:10131)

更新：

export class CheckoutComponent implements OnInit {
          isOTPFieldEnabled:boolean=false;
          isDiableSignInOTPField:boolead =false;

           ngOnInit(){}

          emailVerified(){
                         this.isOTPFieldEnabled=true;
                         }
          getOTP(OTP){
                      if(OTP){
                               this.isDiableSignInOTPField=true;
                              }
         }

}

Answer 1

查看生命周期挂钩文档将ngOnInit()更改为ngAfterContentInit()。可能会对您有帮助。

ngAfterContentInit(){
      this.emailVerified();                         
      this.getOTP(OTP);
     }

    this.emailVerified() {
       this.isOTPFieldEnabled=true;
     }

    this.getOTP(OTP) {
        if(OTP) {
            this.isDiableSignInOTPField=true;
        }
     }

错误错误：Angular 5中的ExpressionChangedAfterItHasBeenCheckedError

1 个答案: