小编Rek*_*kha的帖子

html代码：

ExpressionChangedAfterItHasBeenCheckedError：检查后表达式已更改。以前的值：'mat-focused: false'。当前值：'mat-focused: true'。

当我单击 packmaterial 输入时，它给出了这个错误。

<div formArrayName="packageArray" *ngFor="let item of packageArray.controls; let i = index;">
                <div [formGroupName]="i" class="add-div" >
                    <p>Level {{i+1}} Pack</p>
                <div class="d-flex justify-content-between">
                       <mat-form-field>
                             <input matInput type="text"  (click)="addLevelPack(i)" placeholder="Package Material" formControlName="packMaterial" required> 

在这一行，我有这个错误

                             </mat-form-field>
                           <mat-form-field>
                                  <input matInput type="text" placeholder="UOM" formControlName="UOM" required>
                          </mat-form-field>
                            <mat-form-field>
                                  <input matInput type="text" placeholder="Quantity" formControlName="Quantity" required>
                            </mat-form-field>
                            <mat-form-field>
                                <input matInput type="text" placeholder="Weight(kgs)" formControlName="weight" required>
                             </mat-form-field>
                         </div>
                    </div>
                 </div>
<div class="btn-custom" (click)="addPackage()">
        <span mat-raised-button style="cursor:pointer">Add packaging +</span>   
    </div>
    <p>Total packaging</p>

       <div *ngFor="let item of …