代码：

//选择图片
  choice: function () {
    var that = this
    console.log(that.data.imgsrc.length);
    if (that.data.imgsrc.length <= 3) {
      var ino = 4 - that.data.imgsrc.length;
      wx.chooseImage({  //从本地相册选择图片或使用相机拍照
        count: ino,
        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: (res) => {
          var tempFilePaths = res.tempFilePaths
          for (var item in res.tempFilePaths) {
            console.log(res.tempFilePaths[item]);
            that.data.imgsrc.push(res.tempFilePaths[item]);
            tempFilePaths = that.data.imgsrc;
            console.log(that.data.imgsrc);
          }

          let size = tempFilePaths.every(item => {   //限制上传图片大小为2M,所有图片少于2M才能上传
            return item.size <= 2000000
          })
          if (size) {
            that.setData({
              imgsrc: tempFilePaths
            })
          }else{
            wx.showToast({
              title:'上传图片不能大于2M!',
              icon:'none'    
            })
          }
        }
      })
    }
    else {
      wx.showToast({
        title: "最多只能上传4张图片",
        image: "/images/icon-warning.png",
      });
    }
  },