页面的head部分，需引入echarts插件，代码如下：

<script type="text/javascript" src="js/echarts.min.js"></script>

页面的body部分，需设置一个指定宽高的div容器，代码如下：

<div id="main" style="width: 600px;height:400px;"></div>

页面的底部，对指定元素开启折线图实例闭关设置好相应的参数，代码如下：

// 基于准备好的dom，初始化echarts实例
var myChart = echarts.init(document.getElementById('main'));

// 指定图表的配置项和数据
var option = {
    title: {
        text: 'Topic'
// 副标题        ,subtext: '随机数'
    },
    tooltip: {
        trigger: 'axis'
    },
    legend: {
        data: ['内存使用情况', '当前数量']
    },
    toolbox: {
        show: true,
        feature: {
            dataView: {
                readOnly: false
            },
            restore: {},
            saveAsImage: {}
        }
    },
    dataZoom: {
        show: false,
        start: 0,
        end: 100
    },
    xAxis: [{
        type: 'category',
        boundaryGap: false,
        data: (function() {
            var now = new Date();
            var res = [];
            var len = 10;
            while (len--) {
                res.unshift(now.toLocaleTimeString().replace(/^\D*/, ''));
                now = new Date(now - 2000);
            }
            return res;
        })()
    }],
    yAxis: [{
        type: 'value',
        scale: true,
        name: '内存使用情况',
        max: 20,
        min: 0,
        boundaryGap: [0.2, 0.2]
    }, {
        type: 'value',
        scale: true,
        name: '当前数量',
        min: 0,
        boundaryGap: [0.2, 0.2]
    }],
    series: [{
        name: '当前数量',
        type: 'line',
        yAxisIndex: 1,
        itemStyle: {normal: {
        	color:'#ffd700', 
        	lineStyle:{color:'#ffd700'}  
        }},
        data: (function() {
            var res = [];
            var len = 10;
            while (len--) {
                res.push(null);
            }
            return res;
        })()
    }, {
        name: '内存使用情况',
        type: 'line',
        smooth:true,
        // itemStyle areaStyle 成为面积图的关键。
        itemStyle: {normal: {
        	color:'#0099ff',
        	areaStyle: {type: 'default'},
        	lineStyle:{color:'#0099ff'}  
        }},
        areaStyle: {// 实现蓝白渐变色
            normal: {
                color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [{
                    offset: 0,
                    color: 'rgb(0, 153, 255)'
                }, {
                    offset: 1,
                    color: 'rgb(255,255,255)'
                }])
            }
        },
        data: (function() {
            var res = [];
            var len = 0;
            while (len < 10) {
                res.push(null);
                len++;
            }
            return res;
        })()
    }]
};
setInterval(function() {
    axisData = (new Date()).toLocaleTimeString().replace(/^\D*/, '');

    var data0 = option.series[0].data;
    var data1 = option.series[1].data;
    data0.shift();
    data0.push(Math.round(Math.random() * 10000));
    data1.shift();
    data1.push(Math.round(Math.random() * 20));

    option.xAxis[0].data.shift();
    option.xAxis[0].data.push(axisData);

    myChart.setOption(option);
}, 1000);