小程序 打卡  拍照上传，为啥偶尔会出现 黑图？ 代码   const ctx = wx.createCameraContext()       ctx.takePhoto({         quality: 'high',          success: (res) => {               wx.uploadFile({              url: App.data.host_path + '********',             filePath: res.tempImagePath,             name: 'file',             formData: {               'rosterId': that.data.userid             },             success(res) {                       let dares = JSON.parse(res.data)               wx.hideLoading({                 complete: (res_hide) => {                   console.log(dares.code)                             if (dares.code == '0000') {                     wx.showModal({                       title: '提示',                       content: '签到成功',                       confirmText: '查看',                       cancelText: '不查看',                       success: (res) => {                         if (res.confirm) {                                                                         } else {                           return                         }                       }                     })                   } else {                     wx.showToast({                       title: dares.msg,                       icon: 'none',                       duration: 2000                     })                                           }                 },               })             },             fail: (res) => {               wx.hideLoading({                 complete: (res_hide) => {                   wx.showToast({                     title: '上传失败',                     icon: 'none',                     duration: 2000                   })                 },               })             }           })            }       }) 代码 运行 没有异常 后台获取图片偶尔出现这种 [图片]