标题：渐变色 阴影 点击缩放echarts 柱状配置项内容和展示

二级标题: Gradient Color, Shadow, Click Zoom

      var dataAxis = ['点', '击', '柱', '子', '或', '者', '两', '指', '在', '触', '屏', '上', '滑', '动', '能', '够', '自', '动', '缩', '放'];
var data = [220, 182, 191, 234, 290, 330, 310, 123, 442, 321, 90, 149, 210, 122, 133, 334, 198, 123, 125, 220];
var yMax = 500;
var dataShadow = [];

for (var i = 0; i < data.length; i++) {
    dataShadow.push(yMax);
}

option = {
    title: {
        text: '标题：渐变色 阴影 点击缩放',
        subtext: '二级标题: Gradient Color, Shadow, Click Zoom'
    },
    xAxis: {
        data: dataAxis,
        axisLabel: {
            // inside: true,// 显示在内部
            textStyle: {
                // color: '#fff'
            }
        },
        axisTick: {
            show: false
        },
        axisLine: {
            show: false
        },
        z: 10
    },
    yAxis: {
        axisLine: {
            show: false
        },
        axisTick: {
            show: false
        },
        axisLabel: {
            textStyle: {
                color: '#999'
            }
        }
    },
    dataZoom: [{
        type: 'inside'
    }],
    series: [{ // For shadow
            type: 'bar',
            itemStyle: {
                color: 'rgba(0,0,0,0.05)'
            },
            barGap: '-100%',
            barCategoryGap: '40%',
            data: dataShadow,
            animation: false
        },
        {
            type: 'bar',
            itemStyle: {
                color: new echarts.graphic.LinearGradient(
                    0, 0, 0, 1,
                    [{
                            offset: 0,
                            color: '#83bff6'
                        },
                        {
                            offset: 0.5,
                            color: '#188df0'
                        },
                        {
                            offset: 1,
                            color: '#188df0'
                        }
                    ]
                )
            },
            emphasis: {
                itemStyle: {
                    color: new echarts.graphic.LinearGradient(
                        0, 0, 0, 1,
                        [{
                                offset: 0,
                                color: '#2378f7'
                            },
                            {
                                offset: 0.7,
                                color: '#2378f7'
                            },
                            {
                                offset: 1,
                                color: '#83bff6'
                            }
                        ]
                    )
                }
            },
            data: data
        }
    ]
};

// Enable data zoom when user click bar.
var zoomSize = 6;
myChart.on('click', function(params) {
    console.log(dataAxis[Math.max(params.dataIndex - zoomSize / 2, 0)]);
    myChart.dispatchAction({
        type: 'dataZoom',
        startValue: dataAxis[Math.max(params.dataIndex - zoomSize / 2, 0)],
        endValue: dataAxis[Math.min(params.dataIndex + zoomSize / 2, data.length - 1)]
    });
});