Why will UIImageView not change to a different image having been set once?

问题

My code

UIImage *img = [UIImage imageWithCGImage:[repr fullResolutionImage]];
[_photoPreview setImage:img];

works fine for the first time. When I want to update the image in _photoPreview however, it will not do so and stays with the original.

I have a vague suspicion that this is to do with when the interface is loaded or something but I could be completely wrong. Any help would be greatly appreciated.

回答1:

I have no problems changing the image in the image view by implementing the following code in a view controller.

#import "ViewController.h"

@interface ViewController ()

@property (weak) IBOutlet UIImageView *imageView;

@end

@implementation ViewController

- (IBAction)selectImage1:(id)sender {
    UIImage *image1 = [UIImage imageNamed:@"pic1.png"];
    [_imageView setImage:image1];
}

- (IBAction)selectImage2:(id)sender {
    UIImage *image2 = [UIImage imageNamed:@"pic2.png"];
    [_imageView setImage:image2];
}

- (IBAction)selectImage3:(id)sender {
    UIImage *image3 = [UIImage imageNamed:@"pic3.png"];
    [_imageView setImage:image3];
}

@end

来源：https://stackoverflow.com/questions/15783641/why-will-uiimageview-not-change-to-a-different-image-having-been-set-once