/** 获取视频缩略图* video_thumbnail库： 如果所选视频已生成过缩略图，那就再次生成时会报错* */getVideoThumbnail(String videoPath,{int maxWidth,int maxHeight,int quality}) async {Completer<String> _completer = Completer<String>();String _thumbPath; //要上传的缩略图本地路径String _photoPath = videoPath.substring(0, videoPath.length - 3) + "jpg"; //将地址后面的mp4去掉，再添加jpg（和imageFormat保持一致），判断这个图片文件是否存在File _photoPathFile = File(_photoPath);var _photoExists = await _photoPathFile.exists();if(_photoExists == true){_thumbPath = _photoPath;}else{_thumbPath = await VideoThumbnail.thumbnailFile(video: videoPath,imageFormat: ImageFormat.JPEG,maxWidth: maxWidth ?? 0,maxHeight: maxHeight ?? 64,quality: quality ?? 25);}_completer.complete(_thumbPath);return _completer.future;}

引用

//图片选择器可以用wechat_assets_picker库// 获取视频缩略图并上传Future <bool> getVideoThumbnail(String videoPath) async {Completer<bool> _completer = Completer<bool>();print('视频文件地址：$videoPath');String thumbnailPath = await Utils().getVideoThumbnail(videoPath);print('thumbnailPath= ${thumbnailPath}');if(thumbnailPath.isEmpty){_completer.complete(false);}else{//上传图片List<String> _fileUrlResult = await UploadOss.uploadByPathList(fileList: [thumbnailPath]);if(_fileUrlResult.isEmpty){_completer.complete(false);}else{state.createExpParams.videoFileUrlPOJODetail.showUrl = _fileUrlResult[0];print('视频封面地址：${state.createExpParams.videoFileUrlPOJODetail.showUrl}');_completer.complete(true);}}return _completer.future;}