让div box居中 flex

<div class="panel-body justify-content-between d-flex">
        <div *ngIf="qrString">
          <qrcode [qrdata]="qrString" [size]="150" [level]="'M'" [attr.title]="''"></qrcode>
        </div> 
      </div>

 让div平均分布

 

.justify-content-between{
    justify-content: space-between !important;
}
.d-flex{
    display: flex !important;
}