ball-applet/pagesSchool/schAdmin/stat/student.js

const app = getApp()
import * as echarts from '../../../commpents/ec-canvas/echarts'
let chart;
Page({
    data: {
        frameStyle: { useTop: true, name: '学员统计', leftArrow: true, useBar: false },
        piedata: []
    },
    // 返回
    back(e) {
        wx.navigateBack({ delta: 1 })
    },
    /**
     * 生命周期函数--监听页面加载
     */

    onLoad: async function (options) {
        const that = this;
        // 监听用户是否登录
        await that.watchLogin();
        that.setData({ ec: { onInit: that.initChart } })
    },
    // 监听用户是否登录
    watchLogin: async function () {
        const that = this;
        wx.getStorage({
            key: 'user',
            success: async res => {
                const arr = await app.$get(`/statistics/schoolStudentAge`, { school_id: res.data.info.id });
                if (arr.errcode == '0') {

                    that.setData({ piedata: arr.data })
                    const option = {
                        series: [{ data: arr.data }],
                    }
                    if (chart) chart.setOption(option)
                }

            },
            fail: async res => {
                wx.redirectTo({ url: '/pages/index/index' })
            }
        })
    },
    // 饼图
    initChart(canvas, width, height, dpr) {
        let that = this;
        var piedata = that.data.piedata;
        const chart = echarts.init(canvas, null, {
            width: width,
            height: height,
            devicePixelRatio: dpr
        });
        canvas.setChart(chart);
        var option = {
            backgroundColor: "#ffffff",
            legend: {
                orient: 'vertical',
                height: 40,
                padding: 50
            },
            series: [{
                label: {
                    normal: {
                        fontSize: 16,
                    }
                },
                type: 'pie',
                center: ['50%', '50%'],
                radius: ['20%', '40%'],
                data: piedata
            }],
            tooltip: {
                trigger: 'item',
                formatter: '{b}:{c}人' + '\n\r' + '({d}%)' // 格式化数值百分比输出
            },
        };
        chart.setOption(option, true);
        return chart;
    },
    /**
   * 生命周期函数--监听页面初次渲染完成
   */
    onReady: function () { },
    /**
     * 生命周期函数--监听页面显示
     */
    onShow: function () {

    },
    /**
     * 页面上拉触底事件的处理函数
     */
    /**
     * 生命周期函数--监听页面隐藏
     */
    onHide: function () {

    },

    /**
     * 生命周期函数--监听页面卸载
     */
    onUnload: function () {

    },

    /**
     * 页面相关事件处理函数--监听用户下拉动作
     */
    onPullDownRefresh: function () {

    },


    /**
     * 用户点击右上角分享
     */
    onShareAppMessage: function (res) {

    },
})