weui户籍所在地无法初始化赋值

.plcolor weui-picker .weui-input::-webkit-input-placeholder {

  color:#000;

  font-size: 16px;

}

.plcolor weui-picker .weui-input::-moz-placeholder{   /* Mozilla Firefox 19+ */

  color:#000;

  font-size: 16px;

}

.plcolor weui-picker .weui-input:-moz-placeholder{    /* Mozilla Firefox 4 to 18 */

  color:#000;

  font-size: 16px;

}

.plcolor weui-picker .weui-input:-ms-input-placeholder{  /* Internet Explorer 10-11 */

  color:#000;

  font-size: 16px;

}

<weui-city-picker

  required

  [ngClass]="{'plcolor':birthAddresspl!=='请选择户籍所在地'}"

  [placeholder]="birthAddresspl"

  [(ngModel)]="birthAddress"

  name="city"

  [data]="birthAddressGroup"

  (change)="birthAddressChange($event)"

   >

</weui-city-picker>