跑马灯滚动在项目中经常会用到,滚动有水平滚动和上下滚动两种方式
1.横向滚动
import 'dart:async';
import 'package:flutter/material.dart';
class YYMarquee extends StatefulWidget {
Duration duration; // 轮播时间
double stepOffset; // 偏移量
double paddingLeft; // 内容之间的间距
List<Widget>children = []; //内容
YYMarquee(
{
this.paddingLeft,
this.duration,
this.stepOffset,
this.children});
_YYMarqueeState createState() => _YYMarqueeState();
}
class _YYMarqueeState extends State<YYMarquee> {
ScrollController _controller; // 执行动画的controller
Timer _timer; // 定时器timer
double _offset = 0.0; // 执行动画的偏移量
@override
void initState() {
super.initState();
_controller = ScrollController(initialScrollOffset: _offset);
_timer = Timer.periodic(widget.duration, (timer) {
double newOffset = _controller.offset + widget.stepOffset;
if (newOffset != _offset) {
_offset = newOffset;
_controller.animateTo(_offset,
duration: widget.duration, curve: Curves.linear); // 线性曲线动画
}
});
}
@override
void dispose() {
_timer.cancel();
_controller.dispose();
super.dispose();
}
Widget _child() {
return new Row(children: _children());
}
// 子视图
List<Widget> _children() {
List<Widget> items = [];
List list = widget.children;
for (var i = 0; i < list.length; i++) {
Container item = new Container(
margin: new EdgeInsets.only(right: widget.paddingLeft),
child: list[i],
);
items.add(item);
}
return items;
}
@override
Widget build(BuildContext context) {
return ListView.builder(
physics:NeverScrollableScrollPhysics(),
scrollDirection: Axis.horizontal, // 横向滚动
controller: _controller, // 滚动的controller
itemBuilder: (context, index) {
return _child();
},
);
}
}
关于使用
Widget _marqueeview() {
return Container(
margin: EdgeInsets.only(left: 15, right: 15),
height: 31,
child: Row(
children: <Widget>[
Padding(
padding: EdgeInsets.only(left: 20, right: 10),
child: Center(
child: Image.asset(
'assets/icon_laba.png',
15,
height: 15,
),
),
),
Expanded(
child: Padding(
padding: EdgeInsets.only(right: 15),
child: YYMarquee(
stepOffset: 200.0,
duration: Duration(seconds: 5),
paddingLeft: 50.0,
children: [
Text(
'手机用户155****0523借款成功',
style: TextStyle(
fontSize: 13,
color: Color(0xFFEE8E2B),
),
),
Text(
'手机用户1345****0531借款成功',
style: TextStyle(fontSize: 13, color: Color(0xFFEE8E2B)),
),
Text(
'手机用户145****0555借款成功',
style: TextStyle(fontSize: 13, color: Color(0xFFEE8E2B)),
),
Text(
'手机用户175****0594借款成功',
style: TextStyle(fontSize: 13, color: Color(0xFFEE8E2B)),
),
Text(
'手机用户185****0521借款成功',
style: TextStyle(fontSize: 13, color: Color(0xFFEE8E2B)),
),
],
),
)),
],
),
decoration: BoxDecoration(
color: Color(0xFFFFF2E6),
borderRadius: BorderRadius.circular(15),
),
);
}
2.纵向滚动,纵向滚动我这里使用的是flutter_Swiper实现的滚动
final list = [
'3月1日王女士(卡号5346)成功借款10000',
'4月3日李女士(卡号3232)成功借款30000',
'2月6日王先生(卡号4432)成功借款10000',
'4月2日刘女士(卡号8908)成功借款50000',
'1月1日张女士(卡号0894)成功借款100000',
'10月1日陈先生(卡号7233)成功借款80000',
'9月1日吴女士(卡号7298)成功借款10000',
];
// 轮播
Widget _marqueeView() {
return Padding(
padding: EdgeInsets.only(left: 16, right: 16, top: 20),
child: Container(
alignment: Alignment.center,
color: ColorConst.Color_Font_White,
height: SIZE_SCALE(34),
child: _marqueeSwiper(),
),
);
}
Widget _marqueeSwiper() {
return Container(
height: SIZE_SCALE(34),
SCREEN_WIDTH(context),
alignment: Alignment.center,
child: Swiper(
itemCount: list.length,
scrollDirection: Axis.vertical,
loop: true,
autoplay: true,
itemBuilder: (BuildContext context, int index) {
// return Text('3月1日李女士(卡号5666)成功借款10000');
return Container(
height: SIZE_SCALE(34),
alignment: Alignment.center,
child: Text(
list[index],
style: TextStyle(
fontSize: FONT_SCALE(13),
color: ColorConst.Color_Font_Gray,
),
),
);
},
),
);
}