series: [
          {
            name: "电流(A)",
            type: "line",
            showBackground: true,
            itemStyle: {
              color: "#437EE0" 
            },
             areaStyle: {
            color: {
                type: 'linear',
                x: 0,
                y: 0,
                x2: 0,
                y2: 1,
                colorStops: [{
                    offset: 0, color: 'rgba(58,132,255, 0.5)' // 0% 处的颜色
                }, {
                    offset: 1, color: 'rgba(58,132,255, 0)' // 100% 处的颜色
                }],
                global: false // 缺省为 false
            }
        },
            data: this.y,
          },
        ],