遇到问题请先查看文档：
https://leancloud.cn/docs/relation-guide.html16

wx.chooseImage({
count: 1,
sizeType: ['original', 'compressed'],
sourceType: ['album', 'camera'],
success: function (res) {

    console.log(res)
    wx.showToast({
      title: '图片已上传',
      icon: 'success',
      image: '',
      duration: 3000,

    })
    this.setData
    var tempFilePath = res.tempFilePaths[0];
    
   new AV.File('banner', {
      blob: {
        uri: tempFilePath,
      },
    })
     
     .save().then(function (file) {
      console.log(file.url());
     var banner = file.url()
     product.set('banner', file.url());

var currentUser = AV.User.current();
product.set('owner', AV.User.current());
product.save().then(function (product) {
console.log(product.id)

       })
     },
      
      
       )  .catch(console.error);
  },


});

},