iOS Parse查询 - 记录不同数字的百分比

Question

我从Parse返回2个不同的查询... 1表示likeCount，1表示dislikeCount。 当我查询每个并将它们设置为等于它们各自的标签时，它们是正确的。我现在试图通过将likeCount除以likeCount + dislikeCount来获得一定比例的喜欢。

当按下按钮并初始化push segue时，将运行查询。有时这会记录正确的数字（通常是第一次）。但是，通常在第一次运行查询之后，一个或两个数字值都不会更新，并输出标签初始文本。

@property (nonatomic, assign) float likeCount;
@property (nonatomic, assign) float dislikeCount;


- (void)queryForUserActivity
{
    //Create an Array to check either user photo
    NSArray *userPhotos = @[self.firstUserPhoto, self.secondUserPhoto];

    PFQuery *queryForLikes = [PFQuery queryWithClassName:kDDActivityClassKey];
    [queryForLikes whereKey:kDDActivityTypeKey equalTo:kDDActivityTypeLikeKey];
    [queryForLikes whereKey:kDDActivityFirstUserPhotoKey containedIn:userPhotos];
    [queryForLikes whereKey:kDDActivitySecondUserPhotoKey containedIn:userPhotos];
    [queryForLikes countObjectsInBackgroundWithBlock:^(int number, NSError *error) {
        self.totalLikesLabel.text = [NSString stringWithFormat:@"%i", number];
    }];

    PFQuery *queryForDislikes = [PFQuery queryWithClassName:kDDActivityClassKey];
    [queryForDislikes whereKey:kDDActivityTypeKey equalTo:kDDActivityTypeDislikeKey];
    [queryForDislikes whereKey:kDDActivityFirstUserPhotoKey containedIn:userPhotos];
    [queryForDislikes whereKey:kDDActivitySecondUserPhotoKey containedIn:userPhotos];
    [queryForDislikes countObjectsInBackgroundWithBlock:^(int number, NSError *error) {
        self.totalDislikesLabel.text = [NSString stringWithFormat:@"%i", number];
    }];

    PFQuery *queryForApprovalPercent = [PFQuery orQueryWithSubqueries:@[queryForLikes, queryForDislikes]];
    [queryForApprovalPercent countObjectsInBackgroundWithBlock:^(int number, NSError *error) {
        if (!error) {
            self.likeCount = [self.totalLikesLabel.text floatValue];
            self.dislikeCount = [self.totalDislikesLabel.text floatValue];
            NSLog(@"%f", self.likeCount);
            NSLog(@"%f", self.dislikeCount);
            float approvalPercentage = (self.likeCount / (self.likeCount + self.dislikeCount)) * 100.0;
            self.approvalPercentageLabel.text = [NSString stringWithFormat:@"%2.0f%%", approvalPercentage];
            if (approvalPercentage < 5) self.approvalPercentageLabel.textColor = [UIColor redColor];
        }
    }];
}