smartmeter-app/echarts-for-weixin-master/pages/saveCanvas/index.js

import * as echarts from '../../ec-canvas/echarts';

let chart = null;

function initChart(canvas, width, height, dpr) {
  chart = echarts.init(canvas, null, {
    width: width,
    height: height,
    devicePixelRatio: dpr // new
  });
  canvas.setChart(chart);

  var option = {
    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'
      }
    },
    legend: {
      data: ['热度', '正面', '负面']
    },
    grid: {
      left: 20,
      right: 20,
      bottom: 15,
      top: 40,
      containLabel: true
    },
    xAxis: [
      {
        type: 'value',
        axisLine: {
          lineStyle: {
            color: '#999'
          }
        },
        axisLabel: {
          color: '#666'
        }
      }
    ],
    yAxis: [
      {
        type: 'category',
        axisTick: { show: false },
        data: ['汽车之家', '今日头条', '百度贴吧', '一点资讯', '微信', '微博', '知乎'],
        axisLine: {
          lineStyle: {
            color: '#999'
          }
        },
        axisLabel: {
          color: '#666'
        }
      }
    ],
    series: [
      {
        name: '热度',
        type: 'bar',
        label: {
          normal: {
            show: true,
            position: 'inside'
          }
        },
        data: [300, 270, 340, 344, 300, 320, 310],
        itemStyle: {
          // emphasis: {
          //   color: '#37a2da'
          // }
        }
      },
      {
        name: '正面',
        type: 'bar',
        stack: '总量',
        label: {
          normal: {
            show: true
          }
        },
        data: [120, 102, 141, 174, 190, 250, 220],
        itemStyle: {
          // emphasis: {
          //   color: '#32c5e9'
          // }
        }
      },
      {
        name: '负面',
        type: 'bar',
        stack: '总量',
        label: {
          normal: {
            show: true,
            position: 'left'
          }
        },
        data: [-20, -32, -21, -34, -90, -130, -110],
        itemStyle: {
          // emphasis: {
          //   color: '#67e0e3'
          // }
        }
      }
    ]
  };

  chart.setOption(option);
  return chart;
}

Page({
  onShareAppMessage: function (res) {
    return {
      title: 'ECharts 可以在微信小程序中使用啦！',
      path: '/pages/index/index',
      success: function () { },
      fail: function () { }
    }
  },
  data: {
    ec: {
      onInit: initChart
    }
  },

  onReady() {
    // tips:正常逻辑不建议这么写，需要保证initChart之后再执行下载
    setTimeout(() => {
      this.save();
    }, 1000);
  },

  save() {
    const ecComponent = this.selectComponent('#mychart-dom-save');

    // 先保存图片到临时的本地文件，然后存入系统相册
    ecComponent.canvasToTempFilePath({
      success: res => {
        console.log("tempFilePath:", res.tempFilePath)

        // 存入系统相册
        wx.saveImageToPhotosAlbum({
          filePath: res.tempFilePath || '',
          success: res => {
            console.log("success", res)
          },
          fail: res => {
            console.log("fail", res)
          }
        })
      },
      fail: res => console.log(res)
    });
  }
});