ios force screen orientation

gistfile1.txt

// 强制横屏
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 = UIInterfaceOrientationPortrait;
    [invocation setArgument:&val atIndex:2];
    [invocation invoke];
}