flutter showGeneralDialog Dialog

1.目前常用的是 我们新建一个组件继承与 Dialog ，Dialog 继承与 StatelessWidget组件 StatelessWidget是不支持 setState(() {});
当我们弹框上需用动态改变状态的时候，我们可以直接继承StatefulWidget 这样也同样可以 弹框，不用在麻烦使用 StatefulBuilder

范例 

调用 

    showGeneralDialog(
        context: context,
        pageBuilder: (context, anim1, anim2) {},
        transitionBuilder: (context, anim1, anim2, child)  {
          return Transform.scale(
              scale: anim1.value,
              child: Opacity(
                  opacity: anim1.value,
                  child: AlertView()
              ));
        });

import 'package:flutter/material.dart';
class AlertView extends StatefulWidget {
  @override
  _AlertViewState createState() => _AlertViewState();
}

class _AlertViewState extends State<AlertView> {

  bool isSelected =false;
  void _onCheckbox(value){
    isSelected =! isSelected;
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Material(
      color: Colors.transparent,
      shadowColor: Colors.transparent,
      child: Center(
        child: Container(
          margin: EdgeInsets.only(left: 40,right: 40),
          padding: EdgeInsets.only(top: 16,bottom: 8),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(10),
            color: Colors.white,
          ),
          child:Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text('温馨提示')
                ],
              ),
              Checkbox(value:isSelected, onChanged:_onCheckbox),
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Expanded(child: _buttonView(text: '取消',onTap: (){})),
                  Expanded(child: _buttonView(text: '确定',onTap: (){})),
                ],
              )

            ],
          ),
        ),
      ),
    );
  }
  Widget _buttonView({String text, Color color, VoidCallback onTap}) {
    return InkWell(
      onTap: onTap,
      child: Container(
        alignment: Alignment.center,
        height: 42,
        child: Text(
          text??'',
      ),
    ));
  }
}