stack嵌套 一般情况下 stack是无法嵌套，出现stack嵌套，布局就会出乱 解决方式：就是第二个stack需要确定宽高
appbar透明
AppBar(
backgroundColor: Colors.transparent,
elevation: 0,
}
container设置背景
Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/icon_login_bg.png'),
fit: BoxFit.cover,
),
),
),
背景图在appBar之下
return new Scaffold(
body: new Stack(
children: <Widget>[
new Container(
color: Colors.blue.shade200,
),
new AppBar(
title: new Text("App bar"),
backgroundColor: Colors.transparent,
elevation: 0.0,
),
new Positioned(
top: 80.0,
left: 0.0,
bottom: 0.0,
right: 0.0,
//here the body
child: new Column(
children: <Widget>[
new Expanded(
child: Container(
color: Colors.grey,
),
)
],
),
),
],
),
);
登陆页面
import 'dart:async';
import 'package:flutte_xms/util/func_util.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class LoginPage extends StatefulWidget {
@override
_LoginPageState createState() => _LoginPageState();
}
class _LoginPageState extends State<LoginPage> {
static const defaultText = '点击获取验证码';
Timer countDownTimer;
String vefifyCountText = defaultText;
TextEditingController _mobileController;
TextEditingController _verifyCodeController;
Focus mobileFocus;
@override
Widget build(BuildContext context) {
double screenWidth = FuntionUtil.screenwidth(context);
double screenHeight = FuntionUtil.screenHeight(context);
return Stack(
children: <Widget>[
Container(
alignment: Alignment.center,
decoration: BoxDecoration(
color: Colors.blue,
image: DecorationImage(
image: AssetImage('assets/icon_login_bg.png'),
fit: BoxFit.cover,
repeat: ImageRepeat.noRepeat,
),
),
),
Scaffold(
backgroundColor: Colors.transparent,
appBar: AppBar(
backgroundColor: Colors.transparent,
elevation: 0,
iconTheme: IconThemeData(
color: Colors.white,
),
),
body: GestureDetector(
onTap: () {
FocusScope.of(context).unfocus();
},
child: Container(
height: screenHeight,
screenWidth,
alignment: FractionalOffset(0.5, 0.7),
child: Padding(
padding: EdgeInsets.zero,
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Stack(
alignment: FractionalOffset(0.5, 0.95),
children: <Widget>[
Container(
color: Colors.transparent,
padding: EdgeInsets.only(top: 15, bottom: 30),
child: Container(
margin: EdgeInsets.only(left: 20, right: 20),
// height: 200,
child: Card(
child: Column(
children: <Widget>[
//请输入手机号
Container(
margin: EdgeInsets.only(
top: 15, left: 12, right: 12),
child: Row(
children: <Widget>[
Container(
height: 54,
30,
alignment: Alignment.center,
padding: EdgeInsets.only(
left: 0, right: 5),
child: Image.asset(
'assets/icon_login_verifycode.png'),
),
Expanded(
child: Container(
margin: EdgeInsets.only(right: 14),
height: 54,
alignment: Alignment.center,
child: Theme(
data: Theme.of(context).copyWith(
splashColor:
Colors.transparent),
child: TextField(
controller: _mobileController,
keyboardType:
TextInputType.number,
textInputAction:
TextInputAction.next,
cursorColor: Colors.orange,
decoration: InputDecoration(
hintText: '请输入手机号',
border: InputBorder.none,
),
inputFormatters: [
LengthLimitingTextInputFormatter(
11)
],
),
),
),
),
],
),
decoration: BoxDecoration(
border: Border(
bottom: BorderSide(
2, color: Colors.orange),
),
),
),
//请输入验证码
Padding(
padding: EdgeInsets.only(
top: 15,
bottom: 80,
left: 12,
right: 12),
child: Container(
child: Row(
children: <Widget>[
Container(
height: 54,
30,
alignment: Alignment.center,
padding: EdgeInsets.only(
left: 0, right: 5),
child: Image.asset(
'assets/icon_login_verifycode.png'),
),
Expanded(
child: Container(
margin:
EdgeInsets.only(right: 14),
height: 54,
alignment: Alignment.center,
child: Theme(
data: Theme.of(context)
.copyWith(
splashColor:
Colors.transparent),
child: TextField(
controller:
_verifyCodeController,
keyboardType:
TextInputType.number,
textInputAction:
TextInputAction.done,
cursorColor: Colors.orange,
decoration: InputDecoration(
hintText: '请输入验证码',
border: InputBorder.none,
),
inputFormatters: [
LengthLimitingTextInputFormatter(
11)
],
),
),
),
),
FlatButton(
splashColor: Colors.transparent,
highlightColor: Colors.transparent,
// disabledColor: Colors.grey,
disabledTextColor: Colors.grey[300],
child: Text(vefifyCountText),
onPressed:
vefifyCountText != defaultText
? null
: () {
//开启倒计时
_startTime();
},
)
],
),
decoration: BoxDecoration(
border: Border(
bottom: BorderSide(
color: Colors.orange, 2),
),
),
),
),
],
),
),
),
),
GestureDetector(
child: FuntionUtil.button(context, '登陆'),
onTap: () {
FocusScope.of(context).unfocus();
},
),
],
),
Padding(
padding: EdgeInsets.only(top: 10),
child: Row(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Image.asset('assets/icon_login_agreed.png'),
SizedBox(
5,
),
Text('用户同意协议和隐私策略'),
],
),
),
Padding(
padding: EdgeInsets.only(top: 20),
child: Text('本产品不对未成年人开放'),
)
],
),
),
),
),
),
],
);
}
//开启定时器
void _startTime() {
//置空
_cancelTime();
countDownTimer = Timer.periodic(Duration(seconds: 1), (t) {
int second = 60 - t.tick;
setState(() {
//60-t.tick代表剩余秒数，如果大于0，设置text为剩余秒数
if (second > 0) {
vefifyCountText = '$second秒后重新获取';
} else {
vefifyCountText = '点击获取验证码';
_cancelTime();
}
});
});
}
//取消定时器
void _cancelTime() {
countDownTimer?.cancel();
countDownTimer = null;
}
@override
void dispose() {
_cancelTime();
super.dispose();
}
}