在单独的屏幕中显示视频缩略图

Question

我能够在我的应用程序中使用内置摄像头录制视频，但我想在下一个屏幕中显示视频缩略图以及其他一些字段，如日期，时间和视频位置。我很惊讶在一个单独的页面上显示视频的缩略图。我无法在下一个屏幕中获取视频文件。有人可以帮忙吗？

视频课 公共类视频扩展AppCompatActivity {     private static final int VIDEO_REQUEST_CODE = 100;

func ConnectionHandler()
{

    let dg = DispatchGroup()

    switch self.RequestType
    {
    case aRequest:
        //if I make a single call here, works fine 
    case bRequest:
        //if I make a single call here, works fine 
    case abRequest:
        //when making requests for both type a and b, can’t get it to work
        dg.enter()

        loader.perform(request: self.userDataRequest)
        { response in
            do
            {
                let json = try response.responseJSON()
                self.structWrapper.aArray = self.loadAArray(dict: json)
            }
            catch let error {
                self.didCancelOrFail(error)
            }

           dg.leave()
        }
        self.dexRequestType = DexRequestTypesEnum.glucoseValues

        dg.enter()

        loader.perform(request: self.userDataRequest)
        { response in
            do
            {
                let json = try response.responseJSON()
                self.structWrapper.bArray = self.loadBArray(dict: json)                }
            catch let error {
                self.didCancelOrFail(error)
            }

          dg.leave()
        }

        group.notify(queue: .main) 
        {
            //will print, but requests are not complete, arrays are empty, even though breakpoints hit in loading them.
          for x in self.structWrapper.aArray                  
           {
             print(x.displayTime + ":" + x.units)
           }
           for y in self.structWrapper.bArray
           {
            print(y.displayTime + ":" + String(y.someNumber) 
           }
            print(“tasks complete”)
         }

    }

}

}