ios - 将 PFObject 分配给 UILabel - 将 PFUser 转换为 NSString 值？

Question

我制作了一个应用程序，以允许用户上传带有附加说明的图像。然后两者都显示在 ScrollView 中。我在图片下方还有一个 UILabel，它应该显示上传用户的详细信息以及上传日期。

但是，目前应该显示用户信息和日期的 UILabel 并没有以我想要的格式(例如“上传者:用户名，日期”)进行显示，而是我获得了以下内容..

下面是用户上传图片时使用的PFObject的代码；

PFObject *imageObject = [PFObject objectWithClassName:@"ReportImageObject"];
        [imageObject setObject:file forKey:@"image"];
        [imageObject setObject:[PFUser currentUser] forKey:@"user"];
        [imageObject setObject:self.descriptionTextField.text forKey:@"comment"];

下面是我将 PFObject 的值分配给 UILabel 的地方；

NSDate *creationDate = reportObject.createdAt;
NSDateFormatter *df = [[NSDateFormatter alloc] init];
    [df setDateFormat:@"HH:mm dd/MM yyyy"];

UILabel *infoLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 210, reportImageView.frame.size.width, 15)];
infoLabel.text = [NSString stringWithFormat:@"Uploaded by: %@, %@", [reportObject objectForKey:KEY_USER], [df stringFromDate:creationDate]];
infoLabel.font = [UIFont fontWithName:@"Arial-ItalicMT" size:9];
infoLabel.textColor = [UIColor blueColor];
infoLabel.backgroundColor = [UIColor clearColor];
[reportImageView addSubview:infoLabel];

术语KEY_USER 定义为@"user"

让我感到困惑的是，我访问 descriptionFieldText.text 的其他标签(图像描述 - 可以在左上角“测试 3”上传的图片上模糊地看到)显示用户输入的内容？即使我在 NSLog 中检查与它关联的 PFObject objectForKey 并且它显示与不需要的 UILabel 相似的格式，但实际的标签访问期望值？

已更新 使用的主要方法

显示上传图像的 View Controller - 显示 UILabel 的地方

-(void)getReportImages{
//Fetch images
PFQuery *query = [PFQuery queryWithClassName:@"ReportImageObject"];

[query orderByDescending:KEY_CREATION_DATE];
[query findObjectsInBackgroundWithBlock:^(NSArray * _Nullable objects, NSError * _Nullable error) {
    if (!error) {
        self.reportsObjectArray = nil;
        self.reportsObjectArray = [[NSArray alloc] initWithArray:objects];
        [self loadReportViews];
    } else {
        [self showErrorView:error];
    }
}];
}

-(void)loadReportViews{
for (id viewToRemove in [self.reportsScroll subviews]) {
    if ([viewToRemove isMemberOfClass:[UIView class]])
        [viewToRemove removeFromSuperview];
}

int originY = 10;

for (PFObject *reportObject in self.reportsObjectArray){
    UIView *reportImageView = [[UIView alloc] initWithFrame:CGRectMake(10, originY, self.view.frame.size.width -20, 300)];

    //Adds image
    PFFile *image = (PFFile*)[reportObject objectForKey:KEY_IMAGE];
    UIImageView *userImage = [[UIImageView alloc] initWithImage:[UIImage imageWithData:image.getData]];
    userImage.frame = CGRectMake(0, 0, reportImageView.frame.size.width, 200);
    [reportImageView addSubview:userImage];

    //Adds image info
    NSDate *creationDate = reportObject.createdAt;
    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    [df setDateFormat:@"HH:mm dd/MM yyyy"];

    UILabel *infoLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 210, reportImageView.frame.size.width, 15)];
    infoLabel.text = [NSString stringWithFormat:@"Uploaded by: %@, %@", [reportObject objectForKey:KEY_USER], [df stringFromDate:creationDate]];
    infoLabel.font = [UIFont fontWithName:@"Arial-ItalicMT" size:9];
    infoLabel.textColor = [UIColor blueColor];
    infoLabel.backgroundColor = [UIColor clearColor];
    [reportImageView addSubview:infoLabel];

    //Adds image description
    UILabel *descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 24, reportImageView.frame.size.width, 15)];
    descriptionLabel.text = [reportObject objectForKey:KEY_COMMENT];
    descriptionLabel.font = [UIFont fontWithName:@"ArialMT" size:13];
    descriptionLabel.textColor = [UIColor whiteColor];
    descriptionLabel.backgroundColor = [UIColor clearColor];
    [reportImageView addSubview:descriptionLabel];

    [self.reportsScroll addSubview:reportImageView];

    originY = originY + reportImageView.frame.size.width + 20;

    NSLog(@"Test of description%@",descriptionLabel);
    NSLog(@"The content of infolabel %@", infoLabel);
}

self.reportsScroll.contentSize = CGSizeMake(self.reportsScroll.frame.size.width, originY);
}

用户分配图像和图像描述的 UIViewController 也是创建 imageObject 的地方

- (void)sendPressed:(id)sender{
[self.descriptionTextField resignFirstResponder];

self.navigationItem.rightBarButtonItem.enabled = NO;

UIActivityIndicatorView *loadingSpinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];

[loadingSpinner setCenter:CGPointMake(self.view.frame.size.width/2.0, self.view.frame.size.height/2.0)];
[loadingSpinner startAnimating];

[self.view addSubview:loadingSpinner];

//Upload a new picture if not currently uploaded.
NSData *pictureData = UIImagePNGRepresentation(self.imageToUpload.image);

PFFile *file = [PFFile fileWithName:@"image" data:pictureData];
[file saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
    if (succeeded) {
        PFObject *imageObject = [PFObject objectWithClassName:@"ReportImageObject"];
        [imageObject setObject:file forKey:@"image"];
        [imageObject setObject:[PFUser currentUser] forKey:@"user"];
        [imageObject setObject:self.descriptionTextField.text forKey:@"comment"];

        [imageObject saveInBackgroundWithBlock:^(BOOL succeeded, NSError * _Nullable error) {
            if (succeeded) {
                [self.navigationController popViewControllerAnimated:YES];
            }
            else {
                NSString *errorString = [[error userInfo] objectForKey:@"error"];
                UIAlertController *errorAlertView = [UIAlertController alertControllerWithTitle:@"Error" message:errorString preferredStyle:UIAlertControllerStyleAlert];
                [errorAlertView addAction:[UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:nil]];
                [self presentViewController:errorAlertView animated:YES completion:nil];
            }
        }];
    }
    else{
        NSString *errorString = [[error userInfo] objectForKey:@"error"];
        UIAlertController *errorAlertView = [UIAlertController alertControllerWithTitle:@"Error" message:errorString preferredStyle:UIAlertControllerStyleAlert];
        [errorAlertView addAction:[UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:nil]];
        [self presentViewController:errorAlertView animated:YES completion:nil];
    }
}progressBlock:^(int percentDone) {
    NSLog(@"Uploaded: %d %%", percentDone);
}];
}

Answer 1

只需使用用户名而不是整个用户对象

PFUser *user = (PFUser*)[reportObject objectForKey:KEY_USER];

UILabel *infoLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 210, reportImageView.frame.size.width, 15)];
infoLabel.text = [NSString stringWithFormat:@"Uploaded by: %@, %@", user.username, [df stringFromDate:creationDate]];
infoLabel.font = [UIFont fontWithName:@"Arial-ItalicMT" size:9];
infoLabel.textColor = [UIColor blueColor];
infoLabel.backgroundColor = [UIColor clearColor];
[reportImageView addSubview:infoLabel];

PFObject *imageObject = [PFObject objectWithClassName:@"ReportImageObject"];
imageObject[@"image"] = file;
imageObject[@"user"] = [PFUser currentUser];
imageObject[@"comment"] = self.descriptionTextField.text;