iOS强制切换横屏、竖屏

切换横竖屏最直接的方式是调用device的setOrientation方法。但是从sdk3.0以后，这个方法转为似有API，如果要上AppStore的话，要慎用！

if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {

[[UIDevice currentDevice] performSelector:@selector(setOrientation:)

withObject:(id)UIInterfaceOrientationLandscapeRight];

}

第二种方式是手动的设置界面元素的旋转，包括状态栏、导航栏和视图。以下代码为从竖屏设置为横屏，坐标系是以竖屏的为基准，所以会出现负数的坐标值。

//设置状态栏旋转

[[UIApplication sharedApplication] setStatusBarOrientation:UIDeviceOrientationLandscapeRight animated:YES];

CGFloat duration = [UIApplication sharedApplication].statusBarOrientationAnimationDuration;

//设置旋转动画

[UIView beginAnimations:nil context:nil];

[UIView setAnimationDuration:duration];

//设置导航栏旋转

self.navigationController.navigationBar.frame = CGRectMake(-204, 224, 480, 32);

self.navigationController.navigationBar.transform = CGAffineTransformMakeRotation(M_PI*1.5);

//设置视图旋转

self.view.bounds = CGRectMake(0, -54, self.view.frame.size.width, self.view.frame.size.height);

self.view.transform = CGAffineTransformMakeRotation(M_PI*1.5);

[UIView commitAnimations];

来源： <http://blog.csdn.net/dickenslian/article/details/7407221>

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一直遇到这个问题,今天终于找到了解决方法.

在我们的项目中经常遇到横竖屏切换,而又有某个特定的界面必须是特定的显示方式(横屏或竖屏).这就需要如下的处理了.

强制转成横屏:

if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {

SEL selector = NSSelectorFromString(@"setOrientation:");

NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]];

[invocation setSelector:selector];

[invocation setTarget:[UIDevice currentDevice]];

int val = UIInterfaceOrientationLandscapeRight;

[invocation setArgument:&val atIndex:2];

[invocation invoke];

}

以上代码支持ARC哟.

方法二： 通过判断状态栏来设置视图的transform属性。

- (void)deviceOrientationDidChange: (NSNotification *)notification

{

UIInterfaceOrientation interfaceOrientation = [[UIApplication sharedApplication] statusBarOrientation];

CGFloat startRotation = [[self valueForKeyPath:@"layer.transform.rotation.z"] floatValue];

CGAffineTransform rotation;

switch (interfaceOrientation) {

case UIInterfaceOrientationLandscapeLeft:

rotation = CGAffineTransformMakeRotation(-startRotation + M_PI * 270.0 / 180.0);

break;

case UIInterfaceOrientationLandscapeRight:

rotation = CGAffineTransformMakeRotation(-startRotation + M_PI * 90.0 / 180.0);

break;

case UIInterfaceOrientationPortraitUpsideDown:

rotation = CGAffineTransformMakeRotation(-startRotation + M_PI * 180.0 / 180.0);

break;

default:

rotation = CGAffineTransformMakeRotation(-startRotation + 0.0);

break;

}

view.transform = rotation;

}