编写初衷
因为项目需要浮动按钮所以我这里开发了一个拖动小部件
核心代码
这里直接上代码
import 'dart:math';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
// ignore: must_be_immutable
class TouchMove extends StatefulWidget {
TouchMove({Key key,this.child}) : super(key: key);
Widget child;
@override
_TouchMoveState createState() => _TouchMoveState();
}
class _TouchMoveState extends State<TouchMove> {
//静止状态下的offset
Offset idleOffset=Offset(ScreenUtil().setWidth(600), ScreenUtil().setHeight(1100));
// //本次移动的offset
// Offset moveOffset=Offset(0, 0);
//本次移动的offset
Offset moveOffset=Offset(ScreenUtil().setWidth(600), ScreenUtil().setHeight(1100));
//最后一次down事件的offset
Offset lastStartOffset=Offset(ScreenUtil().setWidth(600), ScreenUtil().setHeight(1100));
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
return GestureDetector(
behavior: HitTestBehavior.deferToChild,
onPanStart: (detail) {
setState(() {
lastStartOffset=detail.globalPosition;
});
},
onPanUpdate: (detail){
setState(() {
moveOffset=detail.globalPosition-lastStartOffset+idleOffset;
moveOffset=Offset(moveOffset.dx, moveOffset.dy);
});
},
onPanEnd: (detail) {
setState(() {
idleOffset=moveOffset*1;
});
},
child:Transform.translate(
offset: moveOffset,
child: Container(
child:widget.child,
))
// widget.child,
);
}
}
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