通过xib .........很容易迁移iPhone5和iPhone4

UIViewController *viewController3;
if ([[UIScreen mainScreen] bounds].size.height == 568)
{
    UIViewController *viewController3 = [[[mainscreenview alloc] initWithNibName:@"iphone5screen" bundle:nil] autorelease];               
}    
else
{
     UIViewController *viewController3 = [[[mainscreenview alloc] initWithNibName:@"iphone4screen" bundle:nil] autorelease];
}

有时候(对于预storyboard应用程序)，如果布局会有足够的不同，在viewController init中根据设备指定不同的xib是值得的(参见这个问题-你需要修改代码来处理iPhone 5)，因为如果你需要不同的图形，再多的自动调整蒙版也不会起作用。

-(id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

    NSString *myNibName;
    if ([MyDeviceInfoUtility isiPhone5]) myNibName = @"MyNibIP5";
    else myNibName = @"MyNib";

    if ((self = [super initWithNibName:myNibName bundle:nibBundleOrNil])) {


...

这对于针对旧iOS版本的应用程序非常有用。

在单例类中尝试下面的方法:

-(NSString *)typeOfDevice
    {
        if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
        {
            CGSize result = [[UIScreen mainScreen] bounds].size;
            if(result.height == 480)
            {
                return @"Iphone";
            }
            if(result.height == 568)
            {
                return @"Iphone 5";
            }
        }
        else{
            return @"Ipad";;
        }


        return @"Iphone";
    }

According to me the best way of dealing with such problems and avoiding couple of condition required for checking the the height of device, is using the relative frame for views or any UI element which you are adding to you view for example: if you are adding some UI element which you want should at the bottom of view or just above tab bar then you should take the y origin with respect to your view's height or with respect to tab bar (if present) and we have auto resizing property as well. I hope this will work for you

你可以使用这个定义来计算你是否使用基于屏幕大小的iPhone 5:

#define IS_IPHONE_5 ( fabs( ( double )[ [ UIScreen mainScreen ] bounds ].size.height - ( double )568 ) < DBL_EPSILON )

然后使用简单的if语句:

    if (IS_IPHONE_5) {

    // What ever changes
    }

Download and install latest version of Xcode. Set a Launch Screen File for your app (in the general tab of your target settings). This is how you get to use the full size of any screen, including iPad split view sizes in iOS 9. Test your app, and hopefully do nothing else, since everything should work magically if you had set auto resizing masks properly, or used Auto Layout. If you didn't, adjust your view layouts, preferably with Auto Layout. If there is something you have to do for the larger screens specifically, then it looks like you have to check height of [[UIScreen mainScreen] bounds] as there seems to be no specific API for that. As of iOS 8 there are also size classes that abstract screen sizes into regular or compact vertically and horizontally and are recommended way to adapt your UI.