旋转全屏 UIImageView

Question

我有两个图像：

Help-Portrait.png (320 x 480)
Help-Landscape.png (480 x 320)

当用户单击任何视图上的帮助按钮时，需要向他们显示正确的图像，并且该图像也应该随着设备的旋转而旋转。我尝试将 imageView 添加到窗口和导航控制器视图中。

由于某种原因，我对此有疑问。 有人能阐明我做错了什么吗？

UIImage *image = nil;
CGRect frame;
if (UIInterfaceOrientationIsPortrait([[UIApplication sharedApplication] statusBarOrientation])) {
    image = [UIImage imageNamed:@"Help-Portrait.png"];
    frame = CGRectMake(0, 0, 320, 480);
} else {
    image = [UIImage imageNamed:@"Help-Landscape.png"];
    frame = CGRectMake(0, 0, 480, 320);
}
if (!helpImageView) {
    helpImageView = [[UIImageView alloc] initWithFrame:frame];
    helpImageView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
    helpImageView.image = image;
}
[[UIApplication sharedApplication] setStatusBarHidden:YES];

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(helpImageTapped:)];
helpImageView.userInteractionEnabled = YES;
[helpImageView addGestureRecognizer:tap];
[self.view addSubview:helpImageView];
[tap release];

willRotateToInterfaceOrientation：

if(helpImageView) {
    [(id)[UIApplication sharedApplication] setStatusBarHidden:NO animated:YES];
    if (UIInterfaceOrientationIsPortrait(toInterfaceOrientation)) {
        helpImageView.image = [UIImage imageNamed:@"Help-Portrait.png"];
    } else {
        helpImageView.image = [UIImage imageNamed:@"Help-Landscape.png"];
    }
}

当您旋转设备时，图像和框架不会改变，最终会在屏幕左侧显示三分之二的肖像图像。

我想要的是它能够显示方向正确的图像，即正确的向上方向。我也想要图像旋转的动画，但这是一个附带问题

Answer 1

您需要调整按钮图像的位置位于 ViewController 的 shouldAutorotateToInterfaceOrientation 方法（为您链接的文档）。

做类似的事情：

- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
    UIImage *image = NULL;

    if (UIInterfaceOrientationIsPortrait(interfaceOrientation))
    {
        image = [UIImage imageNamed:@"Help-Portrait.png"];
    } else {
        image = [UIImage imageNamed:@"Help-Landscape.png"];
    }
    [yourButton setImage: image forState: UIControlStateNormal]
    return YES;
}

Answer 2

Michael Dautermann 的答案看起来几乎包含了所有答案，但我反对使用shouldAutorotateToInterfaceOrientation。此方法的设计目的只是为了确定是否应该发生旋转，仅用于确定是否应该发生旋转。

您应该使用 didRotateFromInterfaceOrientation: willAnimateRotationToInterfaceOrientation:duration 来代替。

didRotateFromInterfaceOrientation: - interfaceOrientation 已在您的 UIViewController 上设置，因此您可以获得当前方向。在这种情况下，旋转动画已经完成。

willAnimateRotationToInterfaceOrientation:duration - 此方法的好处是执行时间。您处于旋转动画内部，因此在旋转动画完成后更改 UI 时不会出现不太漂亮的效果。

Answer 3

使用这段代码让它工作：

- (void)showHelpImage {

    NSString *imageName = @"Help_Portrait.png";
    CGRect imageFrame = CGRectMake(0, 0, 320, 480);

    helpImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
    helpImageView.frame = imageFrame;
    [self.view addSubview:helpImageView];
    [self updateHelpImageForOrientation:self.interfaceOrientation];

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(helpImageTapped:)];
    helpImageView.userInteractionEnabled = YES;
    [helpImageView addGestureRecognizer:tap];
    [self.view addSubview:helpImageView];
    [tap release];
}

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    [self updateHelpImageForOrientation:toInterfaceOrientation];
}

- (void)updateHelpImageForOrientation:(UIInterfaceOrientation)orientation {
    NSString *imageName = nil;
    CGRect imageFrame = helpImageView.frame;
    if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown) {
        imageName = @"Help_Portrait.png";
        imageFrame = CGRectMake( 0, 0, 320, 480);
    } else if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight) {
        imageName = @"Help_Landscape.png";
        imageFrame = CGRectMake( 0, 0, 480, 320);
    }
    helpImageView.image = [UIImage imageNamed:imageName];
    helpImageView.frame = imageFrame;
}

得到这个想法：
http:// www.dobervich.com/2010/10/22/fade-out-default-ipad-app-image-with-proper-orientation/