怎么显示当前鼠标所在的那条线的当前数据

描述:当前是关于Echarts图表中的 折线图 示例。
 
            option = {
    title: {
        //text: ''
    },
    tooltip: { //提示框内容
        trigger: 'axis',
        formatter: function(params) {
            console.log(JSON.stringify(params));

            var res = '' //'<div ><div style="display:inline;background: #eba538;width:16px;height16px;">22</div>&nbsp;&nbsp;<p style="display:inline;">'+params[0].seriesName+'</p></div>'
            for (var i = 0; i < params.length; i++) {
                res += '<p>' + params[i].seriesName + ':' + params[i].data + '</p>'
            }
            return res;
        },
    },
    legend: {
        show: false
        //data:['邮件营销','联盟广告','视频广告','直接访问','搜索引擎']
    },
    grid: {
        left: '3%',
        right: '4%',
        bottom: '3%',
        containLabel: true
    },
    /*toolbox: {
    	feature: {
    		saveAsImage: {}
    	}
    },*/
    xAxis: {
        type: 'category',
        boundaryGap: false,
        data: ['周一', '周二', '周三', '周四', '周五', '周六', '周日'],
        splitLine: { //背景网格设置
            show: true,
            interval: 'auto',
            lineStyle: {
                color: ['#cccccc']
            }
        },
        axisTick: {
            show: false
        },
        axisLine: { //文字颜色
            lineStyle: {
                color: '#000000'
            }
        },
        axisLabel: {
            margin: 10,
            textStyle: {
                fontSize: 14
            }
        }
    },
    yAxis: {
        type: 'value',
        splitLine: { //背景网格设置
            lineStyle: {
                color: ['#cccccc']
            }
        },
        axisTick: {
            show: false
        },
        axisLine: { //文字颜色
            lineStyle: {
                color: '#000000'
            }
        },
        axisLabel: {
            margin: 10,
            textStyle: {
                fontSize: 14
            }
        }
    },
    series: [{
            name: '邮件营销',
            type: 'line',
            stack: '总量',
            symbol: "none", //ECharts 去掉折线上面的小圆点
            /*itemStyle: {  //设置折线上面的小圆点颜色
            	normal: {
            		color: function(params) {
            			// build a color map as your need.
            			var colorList = [
            				'#C1232B', '#B5C334', '#FCCE10', '#E87C25', '#27727B',
            				'#FE8463', '#9BCA63'
            			];
            			return colorList[params.dataIndex]
            		}
            	}
            },*/
            lineStyle: {
                color: '#C1232B'
            },
            data: [120, 132, 101, 134, 90, 230, 210]
        },
        {
            name: '联盟广告',
            type: 'line',
            stack: '总量',
            symbol: "none",
            lineStyle: {
                color: '#B5C334'
            },
            data: [220, 182, 191, 234, 290, 330, 310]
        },
        {
            name: '视频广告',
            type: 'line',
            stack: '总量',
            symbol: "none",
            lineStyle: {
                color: '#FCCE10'
            },
            data: [150, 232, 201, 154, 190, 330, 410]
        },
        {
            name: '直接访问',
            type: 'line',
            stack: '总量',
            symbol: "none",
            lineStyle: {
                color: '#E87C25'
            },
            data: [320, 332, 301, 334, 390, 330, 320]
        },
        {
            name: '搜索引擎',
            type: 'line',
            stack: '总量',
            symbol: "none",
            lineStyle: {
                color: '#27727B'
            },
            data: [820, 932, 901, 934, 1290, 1330, 1320]
        }
    ]
}