把ucharts 封装成组件

最后的转Uni-app项目开发，要用图表，一个页面上有好几个图表，单个写的话，代码量大也麻烦。没办法。只能封装组件了；（本人的项目只用到柱状图和饼图）

组件页面：

<style lang="scss" scoped>
#template {
     100%;
    height: 700rpx;
    .charts {
         100%;
        height: 100%;
    }
}
</style>
<template>
    <view id="template"><canvas :canvas-id="canvasData.id" :id="canvasData.id" class="charts" @touchstart="touchColumn"></canvas></view>
</template>
<script>
import uCharts from '@/components/u-charts/u-charts.js';
var _self;//只要一个_self；
export default {
    data() {
        return {
            cWidth: '',
            pixelRatio: 1,
            cHeight: '',
        };
    },
    props: ['canvasData'],
    name: 'mycanvas',
    methods: {
        //
        // 生成图表
        showColumn(chartData) {
            // 用props回的data添加一个属性用来生成canvas，以用来控制对应tooltip
            this.canvasData.canvas = new uCharts({
                $this: _self,
                canvasId: chartData.id,
                type: chartData.type,
                fontSize: 12,
                background: '#FFFFFF',
                pixelRatio: this.pixelRatio,
                animation: true,
                categories: chartData.categories,
                series: chartData.series,
                colors: ['#0b974e', '#ffcc00', '#2fce77', '#7030a0', '#ff0000', '#004a96'],
                xAxis: {
                    disableGrid: true
                },
                yAxis: {
                    min: 0,
                    format: val => {
                        return val.toFixed(0);
                    },
                    titleFontColor: '#ff0000',
                    title: '日期'
                },
                legend: {
                    show: true,
                    position: 'top',
                    float: 'center',
                    itemGap: 10,
                    padding: 5,
                    lineHeight: 26,
                    margin: 5,
                    borderWidth: 1
                },
                padding: [5, 35, 5, 5],
                dataLabel: true,
                 _self.cWidth,
                height: _self.cHeight,
                extra: {
                    column: {
                        type: 'group',
                         (_self.cWidth * _self.pixelRatio * 0.5) / chartData.series.length
                    },
                    pie: {
                        labelWidth: 15
                    }
                }
            });
            
        },
        //
        // 点击图表显示tooltip
        touchColumn(e) {
            if (this.canvasData.type != 'pie') {
                this.canvasData.canvas.showToolTip(e, {
                    textList: [{ text: '日期:' }, { text: 'OEE:' }],
                    format: function(item, category) {
                        this.textList = [
                            {
                                text: item.name + ': ' + item.data.value + (item.name == 'OEE' ? '%' : '')
                            },
                            { text: '日期 : ' + item.data.day }
                        ];
                    }
                });
            } else {
                this.canvasData.canvas.showToolTip(e, {
                    textList: [],
                    format: function(item, category) {
                        let p = Math.round(item._proportion_ * 10000) / 100;
                        this.textList = [{ text: item.name + ' : ' + item.data + '分钟' }, { text: '占比 : ' + p + '%' }];
                    }
                });
            }
        }
    },
    mounted() {
        _self = this;
        this.cWidth = uni.upx2px(750);
        this.cHeight = uni.upx2px(600);
    },
    watch: {
        'canvasData.day': {
            // 监听数据变化后重新生成图表
            handler(newName, oldName) {
                setTimeout(() => {
                    this.showColumn(this.canvasData);
                }, 100);
            },
            immediate: true,
            deep: true
        }
    }
};
</script>

在页面引用

template

<u-canvas :canvasData="metreData"></u-canvas>

JS里面

import uCanvas from './canvas';
export default {
    data() {
        return {
            metreData: { type: 'column', categories: [], series: [], id: 'metre', canvas: null, day: 0 },
        };
    },
    components: {
        uCanvas
    },
    methods: {
    },
    onLoad(item) {

    }
};
</script>

这样把获取到的数据再赋值就可以了。还有如果 过多图表，建议加延迟。要不然容易 卡