导航 View Controller 中的 IOS 图像选择器

Question

我正在尝试使用 UIImagePickerController 浏览图像并在 imageview 中显示。基本上，我用来浏览图像的 View 是基于 navigationController 的。

但是在我选择图像并返回查看后使用下面的代码，我可以看到 View 在左右闪烁并且图像没有显示在 ImageView 中。

实际上整个源代码很长，这就是为什么我只发布图像选择器部分的原因。如果需要，我可以发布更多代码。

RegistrationFormViewController.h

@interface RegistrationFormViewController : ViewController
<UIImagePickerControllerDelegate,UINavigationControllerDelegate,CLLocationManagerDelegate>
{
    CLLocationManager *locationManager;
    UIImagePickerController *imagePickerController;
}
@property (strong, nonatomic) CLLocationManager *locationManager;
@property (weak, nonatomic) IBOutlet UIImageView *imageUser;

- (IBAction)registerBt:(id)sender;

RegistrationFormViewController.m

- (void)viewDidLoad {
    [super viewDidLoad];

    _barButtonBack.target = self.revealViewController;
    _barButtonBack.action = @selector(revealToggle:);
    [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];


    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapDetected)];
    singleTap.numberOfTapsRequired = 1;
    [self.imageUser setUserInteractionEnabled:YES];
    [self.imageUser addGestureRecognizer:singleTap];
}



-(void)tapDetected{
    NSLog(@"single Tap on imageview");
    imagePickerController = [[UIImagePickerController alloc]init];
    imagePickerController.delegate = self;
    imagePickerController.sourceType =  UIImagePickerControllerSourceTypePhotoLibrary;
    [self presentViewController:imagePickerController animated:YES completion:nil];
}

#pragma mark - ImagePickerController Delegate

- (void)imagePickerController:(UIImagePickerController *)picker
        didFinishPickingImage:(UIImage *)image
                  editingInfo:(NSDictionary *)editingInfo
{
    // Dismiss the image selection, hide the picker and

    //show the image view with the picked image

    [picker dismissViewControllerAnimated:YES completion:nil];
    [self.imageUser setImage:image];

     self.imageUser.contentMode = UIViewContentModeScaleAspectFill;
}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [picker dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

您在此处显示的代码没有问题。但是在 didFinishPickingImage 中试试这个 -

dispatch_async(dispatch_get_main_queue(), ^{
    self.imageUser.contentMode = UIViewContentModeScaleAspectFill;
     [self.imageUser setImage:image];

    });

并将此代码移动到 viewDidLoad

imagePickerController = [[UIImagePickerController alloc]init];
    imagePickerController.delegate = self;
    imagePickerController.sourceType =  UIImagePickerControllerSourceTypePhotoLibrary;

您还可以使用断点检查是否正在获取图像。