echarts 图例过多分页显示，且定时切换页数
echarts 的配置项：legend配置如下：type: ‘scroll’,

		show: true,
        type: 'scroll',
        orient: 'vertical',
        right: '10px',
        top: 0,
        bottom: 0,
        icon: "circle",
        data: data,
        width: 4,
        padding: [0, 0],
        itemWidth: 10,
        itemHeight: 10,
        itemGap: 4,
        formatter: function(name) {
          var val = 0;
          for(var i=0; i<data.length; i++){
            if(data[i].name == name){
              val = data[i].value;
            }
          }
          return "{title|" + (name.length>4 ? (name.slice(0, 4)+'...') : name) + "} {value|" + (val) + "}"
        },

没找到echarts本身获取总页数的地方，自己算了下页数：

var pageNum = Math.ceil(data.length / 4);   //4 是每页显示的条数

var myChart = echarts.init(chartsPieDom);

然后：

var curNum = 1;
myChart .on('finished', function () {
    clearInterval(objTimer);
    objTimer = setInterval(function(){
      var index = (curNum % obj.pageNum)*4;
      obj.charts.dispatchAction({
        type: 'legendScroll',
        scrollDataIndex: index
      });
      curNum++;
    }, 2000)
  });