此代码是否正确处理iAd / AdMob中介

Question

 -(void)bannerViewDidLoadAd:(ADBannerView *)banner{

[UIView beginAnimations:nil context:nil];

[UIView setAnimationDuration:1];

[iAdbanner setAlpha:1];   

[UIView commitAnimations];

 [self.iAdbanner setDelegate:self];   

_bannerView.hidden=YES;   

_bannerView = [[GADBannerView alloc] initWithAdSize:kGADAdSizeSmartBannerPortrait]; 

}

-(void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error{


[UIView beginAnimations:nil context:nil];

[UIView setAnimationDuration:1];

[iAdbanner setAlpha:0];  

[UIView commitAnimations];

_bannerView.hidden=NO;  


NSLog(@"iAd fails");

 _bannerView = [[GADBannerView alloc] initWithAdSize:kGADAdSizeSmartBannerPortrait]; 

 _bannerView=[[GADBannerView alloc]initWithFrame:CGRectMake(0, 0, 320, 50)];

 self.bannerView.adUnitID=@"UNIT-ID";

 self.bannerView.rootViewController=self;

 [self.view addSubview:self.bannerView];

 GADRequest *request =[GADRequest request];

 request.testDevices= @[ GAD_SIMULATOR_ID ];  

 [self.bannerView loadRequest:request];

}

我将上面的代码放在ViewController1.m中，并且始终只有AdMob测试横幅加载。然后我将相同的代码放在View Controller2.m和ONLY iAd测试横幅加载，而不是AdMob。为什么会这样？代码错了吗？我处理调解错了吗？

我认为CPM iAd比AdMob更重要。 NSLog语句“iAd failed”从未出现过。