试试下面的代码，希望我认为你的问题已经解决了，只是改变IconPosition是trailing而不是leading

Container(
      width: MediaQuery.of(context).size.width * 0.80,
      height: 50.0,
      child: IntlPhoneField(
        showDropdownIcon: true,
        iconPosition: IconPosition.trailing,
        decoration: InputDecoration(
          labelText: 'Phone Number',
          border: OutlineInputBorder(
              borderRadius: BorderRadius.all(Radius.circular(10.0))),
        ),
        initialCountryCode: 'PK',
        onChanged: (phone) {
          print(phone.completeNumber);
        },
      ),
    ),

我的Widget图像-> x1c 0d1x您的结果屏幕->

你可以用

Container(
  width: MediaQuery.of(context).size.width * 0.80,
  height: 50.0,
  child: IntlPhoneField(
    showDropdownIcon: true,
    dropdownIconPosition: IconPosition.trailing, // <= Use This ******
    decoration: InputDecoration(
      labelText: 'Phone Number',
      border: OutlineInputBorder(
          borderRadius: BorderRadius.all(Radius.circular(10.0))),
    ),
    initialCountryCode: 'PK',
    onChanged: (phone) {
      print(phone.completeNumber);
    },
  ),
),