iOS 切换横竖屏

参照：iOS强制转换横竖屏和键盘方向控制

实现点击按钮切换横竖屏的功能，设备锁屏无影响。效果如图所示：

手动切换横竖屏.gif

方法一：通过setOrientation:方法
首先，要保证支持横竖屏，你需要在这里进行设置

支持横竖屏.png

其次，对需要旋转的界面进行处理：需要支持屏幕旋转，可对支持的方向进行控制

-(BOOL)shouldAutorotate{        //需要支持旋转屏幕
    return YES;    //默认YES
}
-(UIInterfaceOrientationMask)supportedInterfaceOrientations{        //控制支持的方向
    return _btn.selected?UIInterfaceOrientationMaskLandscapeRight:UIInterfaceOrientationMaskPortrait;    //不希望屏幕自动旋转，通过这里控制，有时会失效。
   //return UIInterfaceOrientationMaskAllButUpsideDown;    //默认和Target中的设置相同
}

然后，就是通过利用NSInvocation调用对象的消息

/**
 切换横竖屏

 @param sender button
 */
- (IBAction)btnAction:(UIButton *)sender {
    
    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 = UIDeviceOrientationPortrait;//竖屏
        UIDeviceOrientation duration = [[UIDevice currentDevice]orientation];
        if (UIDeviceOrientationPortrait == duration) {
            val = UIInterfaceOrientationLandscapeLeft;//横屏
        }
        
        [invocation setArgument:&val atIndex:2];
        [invocation invoke];
    }
}

补充：上面有提到，不希望屏幕自动旋转，控制时有时会失效，比如你点击了按钮之后，旋转了手机，再次点击按钮。解决办法，添加监听设备方向的通知，如果是手动触发旋转屏，则返回；如果是设备旋转触发旋转屏，则重置屏幕方向。

    //添加监听设备方向的通知
    _inteface = UIInterfaceOrientationMaskPortrait;
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientChange:)name:UIDeviceOrientationDidChangeNotification object:nil];
//监听设备方向的通知方法
- (void)orientChange:(NSNotification *)noti {
    if (_isManualRotate) {
        _isManualRotate = NO;
        return;
    }
    if (_inteface == UIInterfaceOrientationMaskPortrait) {
        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 = UIInterfaceOrientationPortrait;
            [invocation setArgument:&val atIndex:2];
            [invocation invoke]; }
    }else {
        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];
        }
    }
}

方法二：通过设置视图的transform
首先：关闭自动旋转，否则状态栏不旋转。值得庆幸的是，界面是否支持旋转不影响效果

-(BOOL)shouldAutorotate{        //必须关闭旋转屏幕
    return NO;      //默认YES
}

然后：调用代码旋转状态栏和视图

    CGFloat duration = [UIApplication sharedApplication].statusBarOrientationAnimationDuration;
    [UIView animateWithDuration:duration animations:^{
        [[UIApplication sharedApplication] setStatusBarOrientation:_btn.selected ? UIInterfaceOrientationLandscapeRight : UIInterfaceOrientationPortrait];
        self.view.transform = _btn.selected ? CGAffineTransformMakeRotation(M_PI_2) : CGAffineTransformIdentity;
        self.view.frame = CGRectMake(0, 0, self.view.frame.size.height, self.view.frame.size.width);
    }];

期待你的评论建议O(∩_∩)O~