IOS强制屏幕横竖屏相互切换

最近项目要做一个html5电子协议，里面涉及到签名，竖屏签名不够，所以需要把屏幕切换到横屏，签完字后把签字内容返回到竖屏中的方框内，由于项目不上AppStore，只用企业证书打包，所以使用下面方式来实现横竖屏切换功能。

bool isPortrait = true;
- (IBAction)changeOri:(id)sender {
    if (isPortrait) {
        if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {
            [[UIDevice currentDevice] performSelector:@selector(setOrientation:) withObject:[NSNumber numberWithInteger:UIInterfaceOrientationLandscapeLeft]];
            isPortrait = false;
        }
    }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 = UIDeviceOrientationPortrait;
            //从2开始是因为0 1 两个参数已经被selector和target占用
            [invocation setArgument:&val atIndex:2];
            [invocation invoke];
            isPortrait = true;
        }
    }
}

IOS强制屏幕横竖屏相互切换

原文：http://blog.csdn.net/jwzhangjie/article/details/47989443