为什么 toolbox 显示不出来echarts category配置项内容和展示

在pc端 toolbox显示不出来是为什么

      option = {
    title: {
        text: '阶梯瀑布图',
        subtext: 'From ExcelHome',
        sublink: 'http://e.weibo.com/1341556070/Aj1J2x5a5'
    },
    tooltip: {
        trigger: 'axis',
        axisPointer: { // 坐标轴指示器，坐标轴触发有效
            type: 'shadow' // 默认为直线，可选为：'line' | 'shadow'
        },
        formatter: function(params) {
            var tar;
            if (params[1].value != '-') {
                tar = params[1];
            } else {
                tar = params[0];
            }
            return tar.name + '<br/>' + tar.seriesName + ' : ' + tar.value;
        }
    },
    legend: {
        data: ['支出', '收入']
    },
    toolbox: {
        show: true,
        feature: {
            mark: {
                show: true
            },
            dataView: {
                show: true,
                readOnly: false
            },
            restore: {
                show: true
            },
            saveAsImage: {
                show: true
            }
        }
    },
    xAxis: [{
        type: 'category',
        splitLine: {
            show: false
        },
        data: function() {
            var list = [];
            for (var i = 1; i <= 11; i++) {
                list.push('11月' + i + '日');
            }
            return list;
        }()
    }],
    yAxis: [{
        type: 'value'
    }],
    series: [{
        name: '辅助',
        type: 'bar',
        stack: '总量',
        itemStyle: {
            normal: {
                barBorderColor: 'rgba(0,0,0,0)',
                color: 'rgba(0,0,0,0)'
            },
            emphasis: {
                barBorderColor: 'rgba(0,0,0,0)',
                color: 'rgba(0,0,0,0)'
            }
        },
        data: [0, 900, 1245, 1530, 1376, 1376, 1511, 1689, 1856, 1495, 1292]
    }, {
        name: '收入',
        type: 'bar',
        stack: '总量',
        itemStyle: {
            normal: {
                label: {
                    show: true,
                    position: 'top'
                }
            }
        },
        data: [900, 345, 393, '-', '-', 135, 178, 286, '-', '-', '-']
    }, {
        name: '支出',
        type: 'bar',
        stack: '总量',
        itemStyle: {
            normal: {
                label: {
                    show: true,
                    position: 'bottom'
                }
            }
        },
        data: ['-', '-', '-', 108, 154, '-', '-', '-', 119, 361, 203]
    }]
};