如何在init方法中更改nib uiimageview图像？

Question

I used the following code to change the image of uiimageview and this works for me

-(void)viewDidLoad{
     [super viewDidLoad];
     UIImage *tempImage = [UIImage imageNamed:@"instant_poetry_small.png" ];
     drawImage.image = tempImage;
}


-(id)initWithImage:(NSString *)img{
    [super viewDidLoad];
    return self;
}

But i want to change image of uiimageview inside init method. For this i tried the following code but it didn't change the image of uiimageview.

-(void)viewDidLoad{
     [super viewDidLoad];
}


-(id)initWithImage:(NSString *)img{
    [super viewDidLoad];
    UIImage *tempImage = [UIImage imageNamed:@"instant_poetry_small.png" ];
    drawImage.image = tempImage;
    return self;
}

Below is my application delegate method

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [[TTURLRequestQueue mainQueue] setMaxContentLength:0];

     TTNavigator *navigator = [TTNavigator navigator];
    navigator.window = _window;

    TTURLMap *map = navigator.URLMap;
    [map from:@"tt://appPhotos" toSharedViewController:[PhotoViewController class]];
    [map from:@"tt://photo/detail?name=(initWithImage:)" toSharedViewController:[PhotoView class]];
    [navigator openURLAction:[TTURLAction actionWithURLPath:[NSString stringWithFormat:@"tt://photo/detail?name=%@",@"level_me_up_small.png"]]];

    [_window makeKeyAndVisible];

    return YES;
}

Can you tell me what is the difference between above sample code?

Answer 1

In the method viewDidLoad the nib is done loading and all UI elements are available. Don't call viewDidLoad from init since there is now way to tell if the view (read nib) is loaded.

The initWithImage methode your wrote isn't correct and does not work in that way. If you do want to create a custom init , it more like this"

-(id)initWithImage:(NSString *)img{
   self= [super init];

   if (self) {
      // Create a property for this call where you keep the image.
      self.drawImage = [UIImage imageNamed:img];
   }

   return self;
}

But this does not load any NIB, so you have to either call super initWithNIB: or create the elements via code.