I have added iAd to my iphone app to be at the top of my app. originally I place it at x=0 and y=-50 so that it comes from off the screen. I use the following code for it in my .m :
- (void)bannerView:(ADBannerView *)abanner didFailToReceiveAdWithError:(NSError *)error
{
if (self.bannerIsVisible)
{
[UIView beginAnimations:@"animateAdBannerOff" context:NULL];
// Assumes the banner view is placed at the bottom of the screen.
banner.frame = CGRectOffset(banner.frame, 0, banner.frame.size.height);
[UIView commitAnimations];
self.bannerIsVisible = NO;
}
}
- (void)bannerViewDidLoadAd:(ADBannerView *)abanner
{
if (!self.bannerIsVisible)
{
[UIView beginAnimations:@"animateAdBannerOn" context:NULL];
// Assumes the banner view is just off the bottom of the screen.
banner.frame = CGRectOffset(banner.frame, 0, banner.frame.size.height);
[UIView commitAnimations];
self.bannerIsVisible = YES;
}
}
When my app launch iAd get displayed at the top without any problem. but when I open another app and come back to it (without killing it so my app is running in the background) the banner moves another 50 pixel down

any idea?
You are adding 50.0px
to banner.frame.origin.y
in both cases.
Anyway: even if you'd be substracting 50.px
in didFailToReceiveAdWithError:
it
could happen that didFailToReceiveAdWithError:
would get called multiple times in a
row and your code could move the banner higher and higher up (-50.0,-100.0,-150.0...).
So it's better to hardcode the hidden & visible positions instead of calculating it.
Try this:
- (void)bannerView:(ADBannerView *)abanner didFailToReceiveAdWithError:(NSError *)error
{
if (self.bannerIsVisible)
{
[UIView beginAnimations:@"animateAdBannerOff" context:NULL];
banner.frame = CGRectMake(0.0,-50.0,banner.frame.size.width,banner.frame.size.height);
[UIView commitAnimations];
self.bannerIsVisible = NO;
}
}
- (void)bannerViewDidLoadAd:(ADBannerView *)abanner
{
if (!self.bannerIsVisible)
{
[UIView beginAnimations:@"animateAdBannerOn" context:NULL];
banner.frame = CGRectMake(0.0,0.0,banner.frame.size.width,banner.frame.size.height);
[UIView commitAnimations];
self.bannerIsVisible = YES;
}
}
来源:https://stackoverflow.com/questions/9820872/xcode-4-3-storyboard-iad-keeps-moving