fluuter 浮动 和 触摸

为什么80%的码农都做不了架构师？>>>   

import 'package:flutter/material.dart';
import 'package:flutter_app/common/common_bar.dart';


class Point{
  double x,y;
  Point(this.x,this.y);
}
class EventWidget extends StatefulWidget {
  @override
  State createState() => new EventState();
}
class EventState extends State {
  var point_1=new Point(100.0, 50.0);

  ChangePointX(double x){
    setState(() {
      this.point_1.x=x;
    });
  }
  ChangePointY(double y){
    setState(() {
      this.point_1.y=y;
    });
  }


  @override
  Widget build(BuildContext context) {
    double width=MediaQuery.of(context).size.width;
     return new Scaffold(
      appBar:commonBar('点击、拖动和其它手势', Icons.home),
      body: new Column(
        children: [
          new Expanded(
            child: new Stack(
              children: [
                new Positioned(
                    left: 0.0,
                    top: 15.5,
                    child: new Container(
                      width: 50.0,
                      height: 50.0,
                      color: Colors.blue,
                    )),
                    new Positioned(
                      left: this.point_1.x,
                      top: this.point_1.y,
                      child: new GestureDetector( // 只能再GestureDetector 内使用时间
                        child: new Container(
                          width: 50.0,
                          height: 50.0,
                          color: Colors.blue,
                        ),
                        //鼠标按下移动事件
                        onVerticalDragUpdate:(e){
                          var x=e.globalPosition.dx-20.0;
                          var y=e.globalPosition.dy-100.0;
//                          print(e.globalPosition.dy);
                          this.ChangePointX(x);
                          this.ChangePointY(y);
                        },
                      )
                    ),
                  new Positioned(
                      left: 0.0,
                      top: 155.5,
                      child: new Container(
                        width: 50.0,
                        height: 50.0,
                        color: Colors.blue,
                      ))
              ],
            ),
          )
        ],
      ),
    );

  }
}

转载于:https://my.oschina.net/woddp/blog/1927045