iphone - ImageView 在设备方向更改时消失 - iPhone - objective-c

Question

当设备在 iPhone 上的方向发生变化时，我正在学习如何更改 UI 布局，我遇到了一个问题..

我有一个主从应用程序，如果我在详细 View 中更改方向，一切正常，但如果我在主视图 Controller 中更改它，然后推送详细 View ，则一切正常，除了我的 ImageView 未显示..

相关代码如下:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
    if (UIDeviceOrientationIsLandscape(orientation)){
        [self layoutLandscape];
    }
    else if (UIDeviceOrientationIsPortrait(orientation)){
        [self layoutPortrait];
    }

    //set up UI elements
    nameLabel.text = name;
    dateOfBirthLabel.text = dateOfBirth;
    numberOfVotesLabel.text = numberOfVotes;
    reasonForFameLabel.text = reasonForFame;
    numberOfStarsLabel.text = numberOfStars;
    [indicator startAnimating];
    //Perform this method in background (gets the product image from URL)
    [self performSelectorInBackground:@selector(loadImage) withObject:nil];

    //Gives UIImageView memeThumb a orange border
    //Must import the QuartsCore Framework for this to work
    [imageView.layer setBorderColor: [[UIColor blackColor] CGColor]];
    [imageView.layer setBorderWidth: 2.0];
}

- (void) layoutLandscape{
    imageView.frame = CGRectMake(20, 20, 200, 150);
    indicator.frame = CGRectMake(150, 40, 20, 20);

    nameMarker.frame = CGRectMake(70, 115, 51, 150);
    dateOfBirthMarker.frame = CGRectMake(20, 135, 101, 180);
    numberOfVotesMarker.frame = CGRectMake(233, 10, 134, 30);
    reasonForFameMarker.frame = CGRectMake(230, 60, 137, 30);
    numberOfStarsMarker.frame = CGRectMake(236, 110, 130, 30);

    nameLabel.frame = CGRectMake(125, 175, 135, 30);
    dateOfBirthLabel.frame = CGRectMake(125, 210, 135, 30);
    numberOfVotesLabel.frame = CGRectMake(372, 10, 134, 30);
    reasonForFameLabel.frame = CGRectMake(372, 60, 135, 30);
    numberOfStarsLabel.frame = CGRectMake(372, 110, 135, 30);
}

- (void) layoutPortrait{
    imageView.frame = CGRectMake(20, 20, 280, 197);
    indicator.frame = CGRectMake(150, 109, 20, 20);

    nameMarker.frame = CGRectMake(106, 225, 51, 30);
    dateOfBirthMarker.frame = CGRectMake(56, 263, 101, 30);
    numberOfVotesMarker.frame = CGRectMake(23, 301, 134, 30);
    reasonForFameMarker.frame = CGRectMake(20, 339, 137, 30);
    numberOfStarsMarker.frame = CGRectMake(27, 377, 130, 30);

    nameLabel.frame = CGRectMake(165, 225, 135, 30);
    dateOfBirthLabel.frame = CGRectMake(165, 263, 135, 30);
    numberOfVotesLabel.frame = CGRectMake(165, 301, 134, 30);
    reasonForFameLabel.frame = CGRectMake(165, 339, 135, 30);
    numberOfStarsLabel.frame = CGRectMake(165, 377, 135, 30);
}

- (void) loadImage {
    NSURL *imageURL = [NSURL URLWithString:URL];
    NSData *data = [NSData dataWithContentsOfURL:imageURL];
    UIImage *image = [UIImage imageWithData:data];
    imageView.image = image;
    [indicator stopAnimating];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation{
    UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
    if (UIDeviceOrientationIsLandscape(orientation)) {
        [self layoutLandscape];
    }
    else if (UIDeviceOrientationIsPortrait(orientation)) {
        [self layoutPortrait];
    }
}

有人有什么想法吗？

Answer 1

如果 View 已经创建并驻留在内存中，则不会调用 viewDidLoad。

尝试将您的代码移动到

-(void) viewWillAppear
{
   UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
    if (UIDeviceOrientationIsLandscape(orientation)){
        [self layoutLandscape];
    }
    else if (UIDeviceOrientationIsPortrait(orientation)){
        [self layoutPortrait];
    }
}