如何控制广告横幅在屏幕上的显示位置？

Question

早上好，

我想设置一个广告横幅出现在屏幕上的顶部或底部某处，所以我一直在做的是这样的;

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) 
    { 

     bannerView_ = [[GADBannerView alloc] initWithAdSize:kGADAdSizeSmartBannerPortrait]; 
     bannerView_.adUnitID = MY_BANNER_UNIT_ID; 
     CGRect screenRect = [[UIScreen mainScreen] bounds]; 
     CGFloat screenWidth = screenRect.size.width; 
     CGFloat screenHeight = screenRect.size.height; 
     CGFloat screenXPos = (screenWidth /2); 
     CGFloat screenYPos = screenHeight - 150; 
     [bannerView_ setCenter:CGPointMake(screenXPos, screenYPos)]; 
     bannerView_.rootViewController = self; 
     bannerView_.adUnitID = MY_BANNER_UNIT_ID; 
     bannerView_.rootViewController = self; 
     [self.view addSubview:bannerView_]; 

    }else{ 

     bannerView_ = [[GADBannerView alloc] initWithAdSize:kGADAdSizeSmartBannerPortrait]; 
     bannerView_.adUnitID = MY_BANNER_UNIT_ID; 
     CGRect screenRect = [[UIScreen mainScreen] bounds]; 
     CGFloat screenWidth = screenRect.size.width; 
     CGFloat screenHeight = screenRect.size.height; 
     CGFloat screenXPos = (screenWidth /2); 
     CGFloat screenYPos = screenHeight -480; 
     [bannerView_ setCenter:CGPointMake(screenXPos, screenYPos)]; 
     bannerView_.rootViewController = self; 
     bannerView_.adUnitID = MY_BANNER_UNIT_ID; 
     bannerView_.rootViewController = self; 
     [self.view addSubview:bannerView_]; 

这是很凌乱，并没有真正的工作我怎么想，比如我想广告横幅出现大约150个像素顶掉任何设备（新iPad/iPhone等）

我会更好地在界面构建器中创建横幅视图吗？但是，如果是这样的话，我将如何实现上述代码？

在此先感谢！

Answer 1

bannerView_ = [[GADBannerView alloc] initWithAdSize:kGADAdSizeSmartBannerPortrait]; 
     bannerView_.adUnitID = MY_BANNER_UNIT_ID; 
     bannerView.frame = CGRectMake(0, 0, 320,150); 
    [bannerView_ setCenter:CGPointMake(screenXPos, screenYPos)]; 
     bannerView_.rootViewController = self; 
     bannerView_.adUnitID = MY_BANNER_UNIT_ID; 
     bannerView_.rootViewController = self; 
     [self.view addSubview:bannerView_];