错误错误:Angular 5 中的 ExpressionChangedAfterItHasBeenCheckedError [英] ERROR Error: ExpressionChangedAfterItHasBeenCheckedError in Angular 5

问题描述

我是 angular 5 的新手，在这里我试图根据条件禁用输入字段.

 
<mat-form-field class="email-field-width"><垫标签>输入 OTP</mat-label><input [attr.disabled]="isDiableSignInOTPField" #OTP (click)="getOTP(OTP.value)" [formControl]="signInOTP" maxlength="6" matInput required placeholder="OTP"><mat-h​​int [ngStyle]="{color:hintColor}">{{hintOTP}}</mat-h​​int></mat-form-field>

页面加载后，此 div 对用户不可见.一旦 *ngIf="isOTPFieldEnabled" 值满足 TRUE，用户将可以看到它.一旦在 getOTP() 方法中验证了用户输入，我想禁用此输入字段.

为此，我设置了 [attr.disabled] 功能运行良好，但出现了标题中提到的错误.

详细错误:

ERROR 错误:ExpressionChangedAfterItHasBeenCheckedError:检查后表达式已更改.以前的值:'mat-focused: true'.当前值:'mat-focused: false'.在 viewDebugError (core.js:7290)在 expressionChangedAfterItHasBeenCheckedError (core.js:7278)在 checkBindingNoChanges (core.js:7380)在 checkNoChangesNodeDynamic (core.js:10263)在 checkNoChangesNode (core.js:10233)在 debugCheckNoChangesNode (core.js:10833)在 debugCheckRenderNodeFn (core.js:10787)在 Object.eval [as updateRenderer] (CheckoutComponent.html:159)在 Object.debugUpdateRenderer [作为 updateRenderer] (core.js:10776)在 checkNoChangesView (core.js:10131)

更新:

导出类 CheckoutComponent 实现 OnInit {isOTPFieldEnabled:boolean=false;isDiableSignInOTPField:boolead =false;ngOnInit(){}电子邮件验证(){this.isOTPFieldEnabled=true;}获取OTP(OTP){如果(OTP){this.isDiableSignInOTPField=true;}}}

解决方案

查看生命周期钩子文档将 ngOnInit() 更改为 ngAfterContentInit().或许能帮到你.

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

I am new to angular 5 ,Here I am trying to disable a input field based on the condition.

 <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>

After the page load this div is not visible to the user .Once the *ngIf="isOTPFieldEnabled" value is meets TRUE it will be visible to the user. And once the user input validated in the getOTP() method I want to disable this input field .

For that I have set [attr.disabled] the functionality is working fine but I got the error as I mentioned in my title.

Detailed Error :

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)

UPDATE:

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

           ngOnInit(){}

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

}

解决方案

Looking at the lifecycle hooks documentation Change ngOnInit() to ngAfterContentInit(). It might help you.

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

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

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

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