iOS如何实现强制转屏、强制横屏和强制竖屏的实例代码

[self interfaceOrientation:UIInterfaceOrientationLandscapeRight];

[self interfaceOrientation:UIInterfaceOrientationPortrait];

- (void)interfaceOrientation:(UIInterfaceOrientation)orientation
{
  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 = orientation;
    // 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];
  }
}