如何使用CKModifyRecordsOperation.perRecordProgressBlock更新进度

Question

这与最近的线程Update progress with MRProgress有关。由于前面的线程，我将cloudkit查询从方便API转换为CKOperations (谢谢Edwin!)。因此，在使用CKModifyRecordsOperation保存记录时，我可以通过perRecordProgressBlock中的日志记录来查看记录的进度，这是很棒的。但是，我试图将这个进度发送回视图控制器，但我不知道如何做到这一点。我已经为我的所有CloudKit方法- CKManager创建了一个类。我遇到的另一个问题是，我不确定何时更新VC中的进度指示符(使用MRProgress框架)。我是在CKManager中调用保存操作之前、期间还是之后调用它？应该在进度== 1.0之前递归地调用它吗？下面是我编写的代码，因此far...every工作正常，除了更新/动画进度指示器(它会显示0%，然后在保存操作完成后消失)。另外，我在我的CKManager类中使用了一个属性(双进度)，我知道这是不正确的，但是我不知道如何做。我也不认为我在下面的CKManager类中声明/定义的回调方法也是正确的。如有任何指导，将不胜感激！

CKManager.h

@property (nonatomic, readonly) double progress;
- (void)recordProgressWithCompletionHandler:(void (^)(double progress))completionHandler;

CKManager.m

    @property (nonatomic, readwrite) double progress;
    - (void)recordProgressWithCompletionHandler:(void (^)(double))completionHandler {

    completionHandler(self.progress);
}

- (void)saveRecord:(NSArray *)records withCompletionHandler:(void (^)(NSArray *, NSError *))completionHandler {

    NSLog(@"INFO: Entered saveRecord...");
    CKModifyRecordsOperation *saveOperation = [[CKModifyRecordsOperation alloc] initWithRecordsToSave:records recordIDsToDelete:nil];

    saveOperation.perRecordProgressBlock = ^(CKRecord *record, double progress) {
        if (progress <= 1) {
            NSLog(@"Save progress is: %f", progress);
            self.progress = progress;
        }
    };

    saveOperation.perRecordCompletionBlock = ^(CKRecord *record, NSError *error) {
        NSLog(@"Save operation completed!");
        completionHandler(@[record], error);
    };

    [self.publicDatabase addOperation:saveOperation];
}

这是一种方法，从相机拍摄照片并调用CKManager类来准备记录并保存到CK以及显示MRProgress指示器.

if (self.imageDataAddedFromCamera) {
            self.hud = [MRProgressOverlayView showOverlayAddedTo:self.myCollectionView animated:YES];
            self.hud.mode = MRProgressOverlayViewModeDeterminateCircular;
            self.hud.titleLabelText = UPLOADING_MSG;
            // prepare the CKRecord and save it
            [self.ckManager saveRecord:@[[self.ckManager createCKRecordForImage:self.imageDataAddedFromCamera]] withCompletionHandler:^(NSArray *records, NSError *error) {
                if (!error && records) {
                    NSLog(@"INFO: Size of records array returned: %lu", (unsigned long)[records count]);
                    CKRecord *record = [records lastObject];
                    self.imageDataAddedFromCamera.recordID = record.recordID.recordName;
                    NSLog(@"INFO: Record saved successfully for recordID: %@", self.imageDataAddedFromCamera.recordID);
                    [self.hud dismiss:YES];
                    [self.hud removeFromSuperview];
                    [self.imageLoadManager addCIDForNewUserImage:self.imageDataAddedFromCamera]; // update the model with the new image
                    // update number of items since array set has increased from new photo taken
                    self.numberOfItemsInSection = [self.imageLoadManager.imageDataArray count];
                    [self updateUI];
                } else {
                    NSLog(@"Error trying to save the record!");
                    NSLog(@"ERROR: Error saving record to cloud...%@", error.localizedDescription);
                    [self.hud dismiss:YES];
                    [self.hud removeFromSuperview];
                    [self alertWithTitle:YIKES_TITLE andMessage:ERROR_SAVING_PHOTO_MSG];
                }
            }];
            // where does this call belong?
            [self.ckManager recordProgressWithCompletionHandler:^(double progress) {
                dispatch_async(dispatch_get_main_queue(), ^{
                    NSLog(@"Updating hud display...");
                    [self.hud setProgress:progress animated:YES];
                });
            }];

Answer 1

您应该将进度处理程序包括在saveRecord调用中，如下所示：

- (void)saveRecord:(NSArray *)records withCompletionHandler:(void (^)(NSArray *, NSError *))completionHandler recordProgressHandler:(void (^)(double))progressHandler {

    NSLog(@"INFO: Entered saveRecord...");
    CKModifyRecordsOperation *saveOperation = [[CKModifyRecordsOperation alloc] initWithRecordsToSave:records recordIDsToDelete:nil];

    saveOperation.perRecordProgressBlock = ^(CKRecord *record, double progress) {
        if (progress <= 1) {
            NSLog(@"Save progress is: %f", progress);
            progressHandler(progress)
        }
    };

    saveOperation.perRecordCompletionBlock = ^(CKRecord *record, NSError *error) {
        NSLog(@"Save operation completed!");
        completionHandler(@[record], error);
    };

    [self.publicDatabase addOperation:saveOperation];
}

然后，您可以这样调用该保存记录：

        [self.ckManager saveRecord:@[[self.ckManager createCKRecordForImage:self.imageDataAddedFromCamera]] withCompletionHandler:^(NSArray *records, NSError *error) {
            if (!error && records) {
                NSLog(@"INFO: Size of records array returned: %lu", (unsigned long)[records count]);
                CKRecord *record = [records lastObject];
                self.imageDataAddedFromCamera.recordID = record.recordID.recordName;
                NSLog(@"INFO: Record saved successfully for recordID: %@", self.imageDataAddedFromCamera.recordID);
                [self.hud dismiss:YES];
                [self.hud removeFromSuperview];
                [self.imageLoadManager addCIDForNewUserImage:self.imageDataAddedFromCamera]; // update the model with the new image
                // update number of items since array set has increased from new photo taken
                self.numberOfItemsInSection = [self.imageLoadManager.imageDataArray count];
                [self updateUI];
            } else {
                NSLog(@"Error trying to save the record!");
                NSLog(@"ERROR: Error saving record to cloud...%@", error.localizedDescription);
                [self.hud dismiss:YES];
                [self.hud removeFromSuperview];
                [self alertWithTitle:YIKES_TITLE andMessage:ERROR_SAVING_PHOTO_MSG];
            }
        }, recordProgressHandler:^(double progress) {
            dispatch_async(dispatch_get_main_queue(), ^{
                NSLog(@"Updating hud display...");
                [self.hud setProgress:progress animated:YES];
            });
        }];

因此，用于更新进度的代码是saveRecord调用的一部分。上面的代码没有经过我的测试。所以我希望我没有打错字