图解自定义 Dialog 对话框

import 'package:flutter/material.dart';
class GenderChooseDialog extends Dialog {  GenderChooseDialog({    Key key,  }) : super(key: key);
  @override  Widget build(BuildContext context) {    return new Padding(        padding: const EdgeInsets.all(12.0),        child: new Material(            type: MaterialType.transparency,            child: new Column(                mainAxisAlignment: MainAxisAlignment.center,                children: <Widget>[                  new Container(                      decoration: ShapeDecoration(                          color: Color(0xFFFFFFFF),                          shape: RoundedRectangleBorder(                              borderRadius: BorderRadius.all(                            Radius.circular(8.0),                          ))),                      margin: const EdgeInsets.all(12.0),                      child: new Column(children: <Widget>[                        new Padding(                            padding: const EdgeInsets.fromLTRB(                                10.0, 40.0, 10.0, 28.0),                            child: Center(                                child: new Text('请选择性别',                                    style: new TextStyle(                                      fontSize: 20.0,                                    )))),                        new Row(                            mainAxisAlignment: MainAxisAlignment.center,                            mainAxisSize: MainAxisSize.max,                            crossAxisAlignment: CrossAxisAlignment.center,                            children: <Widget>[                              _genderChooseItemWid(1),                              _genderChooseItemWid(2)                            ])                      ]))                ])));  }
  Widget _genderChooseItemWid(var gender) {    return GestureDetector(        child: Column(children: <Widget>[      Image.asset(          gender == 1              ? 'images/icon_type_boy.png'              : 'images/icon_type_girl.png',          width: 135.0,          height: 135.0),      Padding(          padding: EdgeInsets.fromLTRB(0.0, 22.0, 0.0, 40.0),          child: Text(gender == 1 ? '我是男生' : '我是女生',              style: TextStyle(                  color: Color(gender == 1 ? 0xff4285f4 : 0xffff4444),                  fontSize: 15.0)))    ]));  }}

class GenderChooseDialog extends Dialog {  var title;  Function onBoyChooseEvent;  Function onGirlChooseEvent;
  GenderChooseDialog({    Key key,    @required this.title,    @required this.onBoyChooseEvent,    @required this.onGirlChooseEvent,  }) : super(key: key);    Widget _genderChooseItemWid(var gender) {    return GestureDetector(        onTap: gender == 1 ? this.onBoyChooseEvent : this.onGirlChooseEvent,        child: Column(children: <Widget>[          Image.asset(              gender == 1 ? 'images/icon_type_boy.png'                  : 'images/icon_type_girl.png',              width: 135.0, height: 135.0),          Padding(              padding: EdgeInsets.fromLTRB(0.0, 22.0, 0.0, 40.0),              child: Text(gender == 1 ? '我是男生' : '我是女生',                  style: TextStyle(                      color: Color(gender == 1 ? 0xff4285f4 : 0xffff4444),                      fontSize: 15.0)))        ]));  }}
// 方法调用void _onItemPressed() {  showDialog(      context: context,      barrierDismissible: false,      builder: (BuildContext context) {        return GenderChooseDialog(            title: '小哥哥小姐姐请选择',            onBoyChooseEvent: () {              Navigator.pop(context);            },            onGirlChooseEvent: () {              Navigator.pop(context);            });      });}