flutter 将全局坐标转换成组件内坐标

╰半橙微兮° 2021-07-24 20:46 819阅读 0赞

1、定义方法
    
    void getChar(BuildContext context,Offset set)
      {
    	    RenderBox box=context.findRenderObject();  获得父组件
    	    var local=box.globalToLocal(set);   将屏幕坐标转换成父组件内的坐标
    	    
    	    local.dx  获取单独的坐标
      }
    
    2、在GestureDetector组件中调用onVerticalDragDown:(x){} ,点击可以获得Offset类型的全局坐标
    
             onVerticalDragDown: (text){  当点击时会获取点击坐标
                  getChar(context, text.globalPosition);    转换成Offset类型
            },

代码示例:

void getChar(BuildContext context,Offset set)
      { 
        RenderBox box=context.findRenderObject();
        var local=box.globalToLocal(set);
    
        print(local.dy);
      }
    ----
    
      return GestureDetector(
        onVerticalDragDown: (text){  //当点击时会获取点击坐标
            getChar(context, text.globalPosition);
        },
        onVerticalDragEnd: (text){ 
          print(text);
        },
        onVerticalDragCancel: (){ 
          print("取消");
        },
        child: Column(
        crossAxisAlignment: CrossAxisAlignment.center,
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
            Icon(Icons.search,size: 15,),
          GestureDetector(
            child:Text('A') ,
            onTap: (){ 
              scroll.animateTo(312, duration: Duration(milliseconds: 200), curve: Curves.easeIn);
            },
          ),
          GestureDetector(
            child:Text('B') ,
            onTap: (){ 
              scroll.animateTo(478, duration: Duration(milliseconds: 200), curve: Curves.easeIn);
            },
          ),
          GestureDetector(
            child:Text('C') ,
            onTap: (){ 
              scroll.animateTo(575, duration: Duration(milliseconds: 200), curve: Curves.easeIn);
            },
          ),
          GestureDetector(
            child:Text('D') ,
            onTap: (){ 
              scroll.animateTo(741, duration: Duration(milliseconds: 200), curve: Curves.easeIn);
            },
          ),
            Text('E'),
            Text('F'),
            Text('G'),
            Text('H'),
            Text('I'),
            Text('J'),
            Text('K'),
            Text('L'),  
            Text('M'),
            Text('N'),
            Text('O'),
            Text('P'),
            Text('Q'),
            Text('R'),
            Text('S'),
            Text('T'),
            Text('U'),
            Text('V'),
            Text('W'),
            Text('X'),
            Text("Y"),
            Text("#")                                   
          ],
        ),
      );