小程序实现多图上传、预览

wxml

  <view class="weui-cell">  <view class="weui-cell__bd">
      <view class="weui-uploader">
        <view class="weui-uploader__hd">
          <view class="weui-uploader__title">点击可预览选好的图片</view>
          <view class="weui-uploader__info">{{pics.length}}/9</view>
        </view>
        <view class="weui-uploader__bd">
          <view class="weui-uploader__files">
            <block wx:for="{{pics}}" wx:for-item="image">
              <view class="weui-uploader__file">
                <image class="weui-uploader__img" src="{{image}}" data-src="{{image}}" bindtap="previewImage"></image>
              </view>
            </block>
          </view>
  　　　　　<view class="delete-btn" data-index="{{index}}" catchtap="deleteImg"></view>
          <!-- isShow 这个是判断是否进行触发点隐藏操作 -->
          <view class="weui-uploader__input-box {{isShow?'true':'hideTrue'}}">
            <view class="weui-uploader__input" bindtap="chooseImage"></view>
          </view>
        </view>
      </view>
    </view>

wxss

page {
  line-height: 1.6;
  font-family: -apple-system-font, "Helvetica Neue", sans-serif;
}
icon {
  vertical-align: middle;
}
.weui-cell {
  padding: 10px 15px;
  position: relative;
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
  align-items: center;
}
.weui-cell_input {
  padding-top: 0;
  padding-bottom: 0;
}
.weui-uploader__hd {
  display: -webkit-box;
  display: -webkit-flex;
  display: flex;
  padding-bottom: 10px;
  align-items: center;
}
.weui-uploader__title {
  flex: 1;
}
.weui-uploader__info {
  color: #b2b2b2;
}
.weui-uploader__bd {
  margin-bottom: -4px;
  margin-right: -9px;
  overflow: hidden;
}
.weui-uploader__file {
  float: left;
  margin-right: 9px;
  margin-bottom: 9px;
}
.weui-uploader__img {
  display: block;
  width: 79px;
  height: 79px;
}
.weui-uploader__input-box {
  float: left;
  position: relative;
  margin-right: 9px;
  margin-bottom: 9px;
  width: 77px;
  height: 77px;
  border: 1px solid #d9d9d9;
}
.weui-uploader__input-box:before, .weui-uploader__input-box:after {
  content: " ";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: #d9d9d9;
}
.weui-uploader__input-box:before {
  width: 2px;
  height: 39.5px;
}
.weui-uploader__input-box:after {
  width: 39.5px;
  height: 2px;
}
.weui-uploader__input {
  position: absolute;
  z-index: 1;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
}

.hideTrue {
  display: none
}

js

var app = getApp();
Page({
  data: {
    pics: [],
    count: [1, 2, 3, 4, 5, 6, 7, 8, 9],
    isShow: true
  },
  onLoad: function (options) {
    // 生命周期函数--监听页面加载
    isShow: (options.isShow == "true" ? true : false)
  },
  // 图片上传
  chooseImage: function () {
    var _this = this,
      pics = this.data.pics;
    wx.chooseImage({
      count: 9 - pics.length, // 最多可以选择的图片张数，默认9
      sizeType: ['original', 'compressed'], // original 原图，compressed 压缩图，默认二者都有
      sourceType: ['album', 'camera'], // album 从相册选图，camera 使用相机，默认二者都有
      success: function (res) {
        // success
        var imgSrc = res.tempFilePaths;   //图片路径
        pics = pics.concat(imgSrc);   //选取的图片的地址数组
        // 控制触发添加图片的最多时隐藏
        if (pics.length >= 9) {
          _this.setData({
            isShow: (!_this.data.isShow)
          })
        } else {
          _this.setData({
            isShow: (_this.data.isShow)
          })
        }
        _this.setData({
          pics: pics
        })
      },
      fail: function () {
        // fail
      },
      complete: function () {
        // complete
      }
    })
  },
  // 图片预览
  previewImage: function (e) {
    var current = e.target.dataset.src
    wx.previewImage({
      current: current,
      urls: this.data.pics
    })
  }

 // 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

  });

 },

uploadimg:function(){//这里触发图片上传的方法
       var pics=this.data.pics;
       app.uploadimg({
           url:'https://........',//这里是你图片上传的接口
           path:pics//这里是选取的图片的地址数组
        });
  },

})

在app.js中写一个多张图片上传的方法,后面引入，你也可以写在一个JS文件中，后面引入：

//多张图片上传
    function uploadimg(data){
     var that=this,
         i=data.i?data.i:0,//当前上传的哪张图片
         success=data.success?data.success:0,//上传成功的个数
         fail=data.fail?data.fail:0;//上传失败的个数
      wx.uploadFile({
            url: data.url, 
            filePath: data.path[i],
            name: 'file',//这里根据自己的实际情况改
            formData:null,//这里是上传图片时一起上传的数据
            success: (resp) => {
               success++;//图片上传成功，图片上传成功的变量+1
               console.log(resp)
                console.log(i);
                //这里可能有BUG，失败也会执行这里,所以这里应该是后台返回过来的状态码为成功时，这里的success才+1
            },
            fail: (res) => {
                fail++;//图片上传失败，图片上传失败的变量+1
                console.log('fail:'+i+"fail:"+fail);
            },
            complete: () => {
                console.log(i);
                i++;//这个图片执行完上传后，开始上传下一张
            if(i==data.path.length){   //当图片传完时，停止调用          
                console.log('执行完毕');
                console.log('成功：'+success+" 失败："+fail);
            }else{//若图片还没有传完，则继续调用函数
                console.log(i);
                data.i=i;
                data.success=success;
                data.fail=fail;
                that.uploadimg(data);
            }
                
            }
        });
    }

效果图，可点击放大预览