canvas如何调试（关于canvas.toDataURL 在iOS运行失败的问题解决）

try {
 // 将canvas对象转化为image.jpg" alt="canvas如何调试（关于canvas.toDataURL 在iOS运行失败的问题解决）" border="0" />

<template>
    <li id="Poster">
        <li class="mask" @click="hidePoster()"></li>
        <canvas ref="canvas" width="588" height="1044" style="display:none;"></canvas>
        <li ref="box" id="Poster-box" @click.stop>
          <span class="close"  @click="hidePoster()"></span>
        </li>
        <p class="tip">长安按海报发送给朋友</p>
    </li>
</template>

<script>
export default {
  data () { // 参数
    const u = navigator.userAgent // ios终端
    const isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/) // ios终端
    return { // 返回参数
      localUrl: isIOS ? location.href.split('#')[0] : location.href, // 当前路径
      canvas: Object // canvas对象
    }
  },
  mounted () {
    this.initCanvas()
  },
  methods: {
    /**
     * 隐藏海报
     */
    hidePoster () {
      this.$emit('hide')
    },
    /**
     * 加载图片
     * @param {Object} img 图片地址
     * @return {Promise} img dom
     */
    loadImage (img) {
      return new Promise((resolve, reject) => {
        // image dom 对象
        const $image = document.createElement('img')
        if (img.isCross_domain) {
          console.log(img.url)
          $image.setAttribute('crossOrigin', 'Anonymous')
        }
        $image.onload = () => {
          resolve($image)
        }
         $image.src = img.url
        $image.onerror = reject
      })
    },
    /**
     * init初始化canvas函数
     */
    async initCanvas () {
      // 获取vue实例
      var vm = this
      vm.$indicator.open({
        text: '加载中...',
        spinnerType: 'fading-circle'
      })
      this.canvas = this.$refs.canvas.getContext('2d')
      this.canvas.height = 400
      this.canvas.width = 300
      this.canvas.fillStyle = '#ffffff'
      this.canvas.fillRect(0, 0, 588, 1044)

      // image urls
      const imgArr = [
        {
          url: require('../assets/poster-banner.jpg" alt="canvas如何调试（关于canvas.toDataURL 在iOS运行失败的问题解决）" border="0" />

 /**
     * 加载图片
     * @param {Object} img 图片地址
     * @return {Promise} img dom
     */
    loadImage (img) {
      return new Promise((resolve, reject) => {
        // image dom 对象
        const $image = document.createElement('img')
        $image.src = img.url
        if (img.isCross_domain) {
          console.log(img.url)
          $image.setAttribute('crossOrigin', 'Anonymous')
        }
        $image.onload = () => {
          resolve($image)
        }
        $image.onerror = reject
      })
    },

var img = new Image,
    canvas = document.createElement("canvas"),
    ctx = canvas.getContext("2d"),
    src = "http://example.com/image"; // insert image url here

img.crossOrigin = "Anonymous";

img.onload = function() {
    canvas.width = img.width;
    canvas.height = img.height;
    ctx.drawImage( img, 0, 0 );
    localStorage.setItem( "savedImageData", canvas.toDataURL("image.jpg" alt="canvas如何调试（关于canvas.toDataURL 在iOS运行失败的问题解决）" border="0" />