使用视图的自动布局功能。它将自动调整到所有分辨率。

为控制器名称后缀为~iphone或~ipad的控制器创建两个xib。在编译时，Xcode将根据设备取正确的xib。

使用大小类，如果你想为iPhone和iPad创建一个单独的xib，如果视图足够简单，可以移植到iPhone和iPad。

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];
}

你可以添加以下代码:

if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone){
        if ([[UIScreen mainScreen] respondsToSelector: @selector(scale)]) {
            CGSize result = [[UIScreen mainScreen] bounds].size;
            CGFloat scale = [UIScreen mainScreen].scale;
            result = CGSizeMake(result.width * scale, result.height * scale);

            if(result.height == 960) {
                NSLog(@"iPhone 4 Resolution");
            }
            if(result.height == 1136) {
              NSLog(@"iPhone 5 Resolution");
            }
        }
        else{
            NSLog(@"Standard Resolution");
        }
    }

这是一个真正的通用代码，你可以创建3个不同的故事板:

设置你的项目通用模式，用iPhone5 storyboard设置你的主故事iPhone，用ipad target storyboard设置ipad main，现在为iPhone添加新的storyboard target，并修改iPhone 4s或更少的分辨率，现在实现你的appdelegate。m

iPhone4/4s (3/ 3g是一样的)一个iPhone5，并使项目通用，与一个新的Storyboard目标为iPad，现在在AppDelegate。在didFinishLaunching下添加以下代码:

    if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone){
        UIStoryboard *storyBoard;

        CGSize result = [[UIScreen mainScreen] bounds].size;
        CGFloat scale = [UIScreen mainScreen].scale;
        result = CGSizeMake(result.width *scale, result.height *scale);

//----------------HERE WE SETUP FOR IPHONE4/4s/iPod----------------------

        if(result.height == 960){
            storyBoard = [UIStoryboard storyboardWithName:@"iPhone4_Storyboard" bundle:nil];
            UIViewController *initViewController = [storyBoard instantiateInitialViewController];
            [self.window setRootViewController:initViewController];
        }

//----------------HERE WE SETUP FOR IPHONE3/3s/iPod----------------------

        if(result.height == 480){
            storyBoard = [UIStoryboard storyboardWithName:@"iPhone4_Storyboard" bundle:nil];
            UIViewController *initViewController = [storyBoard instantiateInitialViewController];
            [self.window setRootViewController:initViewController];
        }
    }

        return YES;
 }

所以你已经为iPhone 3/ 3g /4/4s/5所有一代的iPod和所有类型的iPad创建了一个通用应用程序

记住将所有IMG与myImage.png和myImage@2x.png集成

使用xCode 5，在项目>General上选择“迁移到资产目录”。

然后使用“Show in finder”找到你的启动图像，你可以模拟编辑它为640x1136，然后拖到资产目录，如下图所示。

确保iOS7和iOS6 R4部分都有一个640x1136的图像。下次你启动应用程序时，黑条将消失，你的应用程序将使用4英寸的屏幕

在iOS设备和iOS模拟器上测试时，有一个小问题。看起来模拟器(XCode 6.0.1)在[[UIScreen mainScreen] bounds]中给出了宽度和高度的切换值。大小，取决于设备方向。

因此，在确定正确的物理屏幕尺寸时，这可能是一个问题。此代码还有助于区分所有2014年。iPhone型号:

iPhone4s iPhone5(和iPhone5s) iPhone6(及iPhone6+)

它也可以很容易地改变，使区别，如iPhone6从iPhone6+。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    CGSize iOSDeviceScreenSize = [[UIScreen mainScreen] bounds].size;

    if ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPhone)
    {
        if (iOSDeviceScreenSize.width > 568 || // for iOS devices
            iOSDeviceScreenSize.height > 568) // for iOS simulator
        {   // iPhone 6 and iPhone 6+

            // Instantiate a new storyboard object using the storyboard file named Storyboard_iPhone6
            storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone6" bundle:nil];

            NSLog(@"loaded iPhone6 Storyboard");
        }
        else if (iOSDeviceScreenSize.width == 568 || // for iOS devices
                 iOSDeviceScreenSize.height == 568) // for iOS simulator
        {   // iPhone 5 and iPod Touch 5th generation: 4 inch screen (diagonally measured)

            // Instantiate a new storyboard object using the storyboard file named Storyboard_iPhone5
            storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone5" bundle:nil];

            NSLog(@"loaded iPhone5 Storyboard");
        }
        else
        {   // iPhone 3GS, 4, and 4S and iPod Touch 3rd and 4th generation: 3.5 inch screen (diagonally measured)

                // Instantiate a new storyboard object using the storyboard file named Storyboard_iPhone4
            storyboard = [UIStoryboard story    boardWithName:@"MainStoryboard_iPhone" bundle:nil];

                NSLog(@"loaded iPhone4 Storyboard");
        }
    }
    else if ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad)
    {   // The iOS device = iPad

        storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPadnew" bundle:nil];

        NSLog(@"loaded iPad Storyboard");
    }

    // rest my code
}