iOS UIImage傳遞舊圖像

Question

在我的應用程序中，我使用API​​從服務器獲取圖像。使用下面的代碼，它可以按照大小順序獲取圖像，以更好的質量取代自己。

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
    NSURL *imageURL = [NSURL URLWithString: [NSString stringWithFormat:@"%@", [[[self.information objectForKey:@"images"]objectForKey:@"normal"] description]]]; 
    NSData *imageData = [NSData dataWithContentsOfURL:imageURL]; 
    self.shotImage = [UIImage imageWithData:imageData]; 
    self.image.image = self.shotImage; 
}); 

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
    NSURL *imageURL = [NSURL URLWithString: [NSString stringWithFormat:@"%@", [[[self.information objectForKey:@"images"]objectForKey:@"hidpi"] description]]]; 
    NSData *imageData = [NSData dataWithContentsOfURL:imageURL]; 
    UIImage *image = [UIImage imageWithData:imageData]; 
    self.image.image = self.shotImage; 
}); 

此外，如果你按圖片，它會帶你另一個ViewController，其中圖像是全屏。

然而，即使我在點擊它之前等待高質量的加載，在PrepareForSegue方法中，它仍然只能通過原始的低質量版本。

看到PrepareForSegue

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender 
{ 
    FullSizeImageViewController *vc = [segue destinationViewController]; 
    UIImage *img = [[UIImage alloc] init]; 
    img = self.shotImage; 
    vc.shotImage = img; 
} 

Answer 1

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
    NSURL *imageURL = [NSURL URLWithString: [NSString stringWithFormat:@"%@", [[[self.information objectForKey:@"images"]objectForKey:@"hidpi"] description]]]; 
    NSData *imageData = [NSData dataWithContentsOfURL:imageURL]; 
    UIImage *image = [UIImage imageWithData:imageData]; 
    self.image.image = self.shotImage; 
}); 

下面的代碼在這段代碼看起來像你錯過了這行：

self.shotImage = [UIImage imageWithData:imageData];