一、切换位置 

二、切换监听 

// 切换事件监听
this.myChart.off('datarangeselected'); // 为了不触发两次
this.myChart.on('datarangeselected',(e) => {// visualMap change
});// 配置如下
visualMap: {type: 'piecewise',showLabel: true,inverse: true,pieces: [{value: 1,label: '东部大区',color: '#c7efac',symbol: 'circle'},{value: 2,label: '西部大区',color: '#2f9fea',symbol: 'circle'},{value: 3,label: '南部大区',color: '#b3edff',symbol: 'circle'},{value: 4,label: '北部大区',color: '#67ccf4',symbol: 'circle'},{value: 5,label: '中部大区',color: '#96e264',symbol: 'circle'},],textStyle: {color: '#666',fontSize: 11,lineHeight: 11},textGap: 8,itemGap: 8,itemSymbol: 'rect',itemWidth: 10,itemHeight: 10,align: 'left',left: 10,bottom: 10,backgroundColor: '#fff',borderColor: '#ddd',borderWidth: 1,padding: [10, 10, 10, 10]
},