修改iPhone通用程序的方向

我想要开发的程序能适应iPad所有方向，在iPhone中只要UIInterfaceOrientationPortrait 和UIInterfaceOrientationPortraitUpsideDown这两个。代码如下：

-(BOOL)shouldAutorotate {
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){
        return NO;
    }else{
        return YES;
    }
}
- (NSUInteger)supportedInterfaceOrientations{

     if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){
         return UIInterfaceOrientationMaskPortrait;
     }else{
        return UIInterfaceOrientationMaskAll;
     }

} 
-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
     if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){

    return interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown ;
     }else{
         return YES;
     }
}

但是不能停在横向模式。

在iPhoneSummary设置中禁用所有方向，除了 UIInterfaceOrientationPortrait 和UIInterfaceOrientationPortraitUpsideDown。如下图：