將數據傳遞給Singleton iOS

Question

從ViewController轉移到PFFile的子類時，我目前遇到數據丟失的問題。傳遞的數據是要上傳到用戶配置文件的圖像數據。下面是選擇圖像的代碼：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{ 
// Access the uncropped image from info dictionary 
UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"]; 

// Dismiss controller 
[picker dismissViewControllerAnimated:YES completion:nil]; 

// Resize image 
_focusedImage.image = image; 


NSData *imageData = UIImageJPEGRepresentation(image, 0.05f); 
PFFile *imageFile = [PFFile fileWithName:@"Image.jpg" data:imageData]; 
[[imageUpload uploadImage] setImagePFFile:imageFile]; 
} 

日誌此視圖imageFile正確地打印出來。然而，當我通過我的單例類imageUpload uploadImage傳遞數據這是數據結構的樣子：

+ (imageUpload *) uploadImage 
{ 
static imageUpload*_sharedImageUpload = nil; 
_sharedImageUpload = [[self alloc] init]; 
_sharedImageUpload.imageData = [[NSData alloc] init]; 

PFUser *user = [PFUser currentUser]; 
_sharedImageUpload.imagePFFile = [[PFFile alloc] init]; 

PFFile *imageFile = [PFFile fileWithName:@"Image.jpg" data:_sharedImageUpload.imageData]; 


[imageFile saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) { 
    if (!error) 
    { 
     [user setObject:imageFile forKey:@"image"]; 
     [user saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) { 
      if (!error) 
      { 
       NSLog(@"This should be the profile image upload"); 
      } 
      else 
      { 
       NSLog(@"Something went wrong: %@", error); 
      } 
     }]; 
    } 
}]; 

return _sharedImageUpload; 
} 

當我到了這一點，該系統只是上傳了一個空文件（零個字節）來分析。命名是正確的，並且它在數據庫的正確位置，但是在該行的某處，文件本身的數據正在丟失。我無法弄清楚爲什麼。有沒有人有什麼建議？

Answer 1

它看起來像你混淆的對象和方法。你想要的是一個單獨的對象，它有一個方法/函數來上傳你的圖像。我認爲這是你在找什麼：

//ImageUploader.h 

#import <Foundation/Foundation.h> 

@interface ImageUploader : NSObject 
+ (instancetype)uploader; 
- (void)uploadImageFile:(PFFile *)aFile; 
@end 

//ImageUploader.m 

#import "ImageUploader.h" 

@implementation ImageUploader 
+ (instancetype)uploader { 
    static ImageUploader * _uploader = nil; 
    static dispatch_once_t onceToken; 
    dispatch_once(&onceToken, ^{ 
     _uploader = [[self alloc] init]; 
    }); 

    return _uploader; 
} 

-(void)uploadPFFile:(PFFile *)imageFile{ 
    [imageFile saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) { 
     if (!error) 
     { 
      [user setObject:imageFile forKey:@"image"]; 
      [user saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) { 
       if (!error) 
       { 
        NSLog(@"This should be the profile image upload"); 
       } 
       else 
       { 
        NSLog(@"Something went wrong: %@", error); 
       } 
      }]; 
     } 
    }]; 
} 
@end 

通過調用[[ImageUploader uploader]uploadImageFile:someFile]調用它。