微信小程序如何实现上传多张图片、删除图片

<view class="con_titles">
 <view class="con_left">
  <image src="../../images/comint.png"></image>
  <text class="titles_t">患者病历</text>
 </view>
 <view class="img_num">{{imgShow.length}}/6</view>
 
 </view>
 <view class="page__bd">
 <!-- <mp-uploader style='color:#353535' bindfail="uploadError" bindsuccess="uploadSuccess" select="{{selectFile}}" upload="{{uplaodFile}}" files="{{files}}" max-count="6" title="患者病历"></mp-uploader> -->
 
 <view class="add-image">
  <view class="images-boxc" wx:for="{{imgShow}}" wx:for-item="item" wx:key="image">
  <image class="image_size" data-index="{{index}}" data-src="{{item}}" src="{{item}}" bindtap="clickImage"></image>
  <image class="delete-image" data-index="{{index}}" src="../../images/delete_img.png" bindtap="deleteImage"></image>
  </view>
  <view class="images-add" wx:if="{{imgShow.length<6}}">
  <image class="image_size image_sizen" src="../../images/add_img.png" bindtap="chooseImage"></image>
  </view>
 </view>
</view>

/* 上传图片 */
.images-boxc {
 position: relative;
 border: dashed 1px #bfbfbf;
 width: 139rpx;
 height: 139rpx;
 margin-right: 32rpx;
 margin-bottom: 32rpx;
}
.delete-image {
 position: absolute;
 width: 30rpx;
 height: 30rpx;
 right: 16rpx;
 top: 16rpx;
}
.add-image {
 display: flex;
 flex-wrap: wrap;
}
.image_size {
 width: 139rpx;
 height: 139rpx;
}
.image_sizen {
 height: 142rpx;
}

data: {
 count: 6, //设置最多6张图片
 
 allImg: [],
 imgShow: [],
 
 },
// 上传图片
 chooseImage: function() {
 wx.showLoading({
  title: '加载中...',
  mask: true
 })
 var that = this;
 var imgShow = that.data.imgShow;
 var count = that.data.count - imgShow.length; //设置最多6张图片
 wx.chooseImage({
  count: count,
  sizeType: ['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: function(res) {
  console.log(res)
  that.uplaodFile(res)
  for (var i = 0, h = res.tempFilePaths.length; i < h; i++) {
   imgShow.push(res.tempFilePaths[i]);
   that.setData({
   imgShow: imgShow
   })
  }
  wx.hideLoading({
   title: '加载中...',
   mask: false
  })
 
  }
 })
 },
 // 删除图片
 deleteImage(e) {
 let self = this;
 let index = e.target.dataset.index;
 let imgShow = self.data.imgShow;
 let allImg = self.data.allImg;
 allImg.splice(index, 1);
 imgShow.splice(index, 1);
 this.setData({
  imgShow: imgShow,
  allImg: allImg
 })
 },
 previewImage: function(e) {
 console.log(this.data.files)
 wx.previewImage({
  current: e.currentTarget.id, // 当前显示图片的http链接
  urls: this.data.files // 需要预览的图片http链接列表
 })
 },
 selectFile(files) {
 console.log('files', files)
 // 返回false可以阻止某次文件上传
 },
 uplaodFile(files) {
 console.log('upload files', files)
 let that = this
 files.tempFilePaths.forEach(element => {
  util.uploadFile('/fastdfsServer/fileUpload', element, 'file', {}, function(res) { //上传本地图片地址到服务器 返回地址 存放到input提交时取值
  res = JSON.parse(res);
  if (res.responseCode == 0) {
   sysMsg.sysMsg("上传成功", 1000, 'success');
   that.setData({
   allImg: that.data.allImg.concat(res.responseBody)
   });
  } else {
   sysMsg.sysMsg("上传失败", 1500, 'error');
  }
  });
 
 });
 // 文件上传的函数，返回一个promise
 return new Promise((resolve, reject) => {
  resolve({
  urls: files.tempFilePaths
  });
  setTimeout(() => {
  reject('some error')
  }, 10000)
 
 })
 
 },
 uploadError(e) {
 console.log('upload error', e.detail)
 },
 uploadSuccess(e) {
 // this.setData({
 // allImg: this.data.allImg.concat(e.detail.urls[0])
 // });
 console.log('upload success', e.detail, e.detail.urls)
 
},