小胖说事30------iOS 强制转成横屏的方式

一直遇到这个问题,今天最终找到了解决方法.

在我们的项目中常常遇到横竖屏切换,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).这就须要例如以下的处理了.

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];
}

- (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;
}

-(BOOL)shouldAutorotate    //是否支持旋转。假设为NO，则下边的方法就不会调用，假设为YES，才会调用
{
    if (!shouldAutorot) {
        return NO;
    }else{
        return YES;
    }
}

-(NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskAllButUpsideDown;
}