微信小程序实现图片上传、删除和预览功能的方法

<view class="img-v">
 <view class="img" wx:for="{{imgs}}" wx:for-item="item" wx:key="*this">
  <image src="{{item}}" data-index="{{index}}" mode="aspectFill" bindtap="previewImg"></image>
  <view class="delete-btn" data-index="{{index}}" catchtap="deleteImg"></view>
 </view>
 <view class="upload-img-btn" bindtap="chooseImg"></view>
</view>

 data: {
  imgs: []
 },
// 上传图片
 chooseImg: function (e) {
  var that = this;
  var imgs = this.data.imgs;
  if (imgs.length >= 9) {
   this.setData({
    lenMore: 1
   });
   setTimeout(function () {
    that.setData({
     lenMore: 0
    });
   }, 2500);
   return false;
  }
  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: function (res) {
    // 返回选定照片的本地文件路径列表，tempFilePath可以作为img标签的src属性显示图片
    var tempFilePaths = res.tempFilePaths;
    var imgs = that.data.imgs;
    // console.log(tempFilePaths + '----');
    for (var i = 0; i < tempFilePaths.length; i++) {
     if (imgs.length >= 9) {
      that.setData({
       imgs: imgs
      });
      return false;
     } else {
      imgs.push(tempFilePaths[i]);
     }
    }
    // console.log(imgs);
    that.setData({
     imgs: imgs
    });
   }
  });
 },
 // 删除图片
 deleteImg: function (e) {
  var imgs = this.data.imgs;
  var index = e.currentTarget.dataset.index;
  imgs.splice(index, 1);
  this.setData({
   imgs: imgs
  });
 },
 // 预览图片
 previewImg: function (e) {
   //获取当前图片的下标
  var index = e.currentTarget.dataset.index;
   //所有图片
  var imgs = this.data.imgs;
  wx.previewImage({
   //当前显示图片
   current: imgs[index],
   //所有图片
   urls: imgs
  })
 }