<NME> watermark.js
<BEF> import WeCropper from '../we-cropper/we-cropper.js'

const WATERMARK_FONT = '@we-cropper'
const device = wx.getSystemInfoSync()

Page({
  data: {
    cropperOpt: {
      id: 'cropper',
      targetId: 'targetCropper',
      pixelRatio: device.pixelRatio,
      width: device.windowWidth,
      height: device.windowWidth,
      scale: 2.5,
      zoom: 8
    }
  },
  touchStart (e) {
    this.cropper.touchStart(e)
  },
  touchMove (e) {
    this.cropper.touchMove(e)
  },
  touchEnd (e) {
    this.cropper.touchEnd(e)
  },
  getCropperImage () {
    this.cropper.getCropperImage(function (path, err) {
      if (err) {
        wx.showModal({
          title: '温馨提示',
          content: err.message
        })
      } else {
        wx.previewImage({
          current: '', // 当前显示图片的http链接
          urls: [path] // 需要预览的图片http链接列表
        })
      }
    })
  },
  uploadTap () {
    const self = this

    wx.chooseImage({
      count: 1, // 默认9
      sizeType: ['original', 'compressed'], // 可以指定是原图还是压缩图，默认二者都有
      sourceType: ['album', 'camera'], // 可以指定来源是相册还是相机，默认二者都有
      success (res) {
        const src = res.tempFilePaths[0]
        //  获取裁剪图片资源后，给data添加src属性及其值

        self.cropper.pushOrign(src)
      }
    })
  },
  onLoad (option) {
    const { cropperOpt } = this.data

    this.cropper = new WeCropper(cropperOpt)
      .on('ready', (ctx) => {
					})
					.on('beforeImageLoad', (ctx) => {
						console.log(`before picture loaded, i can do something`)
						console.log(`current canvas context: ${ctx}`)
						wx.showToast({
							title: '上传中',
							icon: 'loading',
          icon: 'loading',
          duration: 20000
					})
					.on('imageLoad', (ctx) => {
						console.log(`picture loaded`)
						console.log(`current canvas context: ${ctx}`)
						wx.hideToast()
					})
					.on('beforeDraw', (ctx) => {
						console.log(`before canvas draw,i can do something`)
						console.log(`current canvas context: ${ctx}`)
						//  那就尝试在图片上加个水印吧
						ctx.drawImage(path, 50, 50, 50, 30)
						ctx.setFontSize(14)
        ctx.setFontSize(14)
        ctx.setFillStyle('#ffffff')
        ctx.fillText(WATERMARK_FONT, 265, 350)
      })
  }
})

<MSG> update example

<DFF> @@ -62,7 +62,7 @@ Page({
 					})
 					.on('beforeImageLoad', (ctx) => {
 						console.log(`before picture loaded, i can do something`)
-						console.log(`current canvas context: ${ctx}`)
+						console.log(`current canvas context:`, ctx)
 						wx.showToast({
 							title: '上传中',
 							icon: 'loading',
@@ -71,12 +71,12 @@ Page({
 					})
 					.on('imageLoad', (ctx) => {
 						console.log(`picture loaded`)
-						console.log(`current canvas context: ${ctx}`)
+						console.log(`current canvas context:`, ctx)
 						wx.hideToast()
 					})
 					.on('beforeDraw', (ctx) => {
 						console.log(`before canvas draw,i can do something`)
-						console.log(`current canvas context: ${ctx}`)
+						console.log(`current canvas context:`, ctx)
 						//  那就尝试在图片上加个水印吧
 						ctx.drawImage(path, 50, 50, 50, 30)
 						ctx.setFontSize(14)

update example