echasrts定义折线图legend的样式-优化

option = {
    title: {
        text: '折线图堆叠'
    },
    tooltip: {
        trigger: 'axis'
    },
    //定义折线图legend的形状哈
    legend: {
        itemWidth: 10,
        itemHeight: 1,
        itemGap: 10,
        data:[  
            {name:'邮件营销',icon:'rect'},
            {name:'联盟广告',icon:'rect'},
            {name:'视频广告',icon:'rect'},
             {name:'直接访问',icon:'rect'},
            {name:'搜索引擎',icon:'rect'}
        ],
    },
    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']
    },
    yAxis: {
        type: 'value'
    },
    series: [
        {
            name: '邮件营销',
            type: 'line',
            stack: '总量',
            data: [120, 132, 101, 134, 90, 230, 210]
        },
        {
            name: '联盟广告',
            type: 'line',
            stack: '总量',
            data: [220, 182, 191, 234, 290, 330, 310]
        },
        {
            name: '视频广告',
            type: 'line',
            stack: '总量',
            data: [150, 232, 201, 154, 190, 330, 410]
        },
        {
            name: '直接访问',
            type: 'line',
            stack: '总量',
            data: [320, 332, 301, 334, 390, 330, 320]
        },
        {
            name: '搜索引擎',
            type: 'line',
            stack: '总量',
            data: [820, 932, 901, 934, 1290, 1330, 1320]
        }
    ]
};

通过 data:[
    {name:'邮件营销',icon:'rect'},
    {name:'联盟广告',icon:'rect'},
    {name:'视频广告',icon:'rect'},
    {name:'直接访问',icon:'rect'},
    {name:'搜索引擎',icon:'rect'}
],//分别修改legend格式 ，缺省则为默认