值得注意的是，在新的Xcode中，你必须将这个图像文件Default-568h@2x.png添加到资产中

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
}

在constants.h文件中，你可以添加以下定义语句:

 #define IS_IPAD UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad 
 #define IS_IPHONE UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone
 #define IS_WIDESCREEN (fabs((double)[[UIScreen mainScreen] bounds].size.height - (double)568) < DBL_EPSILON) 
 #define IS_IPHONE_5 (!IS_IPAD && IS_WIDESCREEN)

你可以手动检查屏幕大小来确定你在哪个设备上:

#define DEVICE_IS_IPHONE5 ([[UIScreen mainScreen] bounds].size.height == 568)

float height = DEVICE_IS_IPHONE5?568:480;
if (height == 568) {
    // 4"

} else {

    // 3"

}

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.

首先，创建两个xib并将所有委托，main类附加到xib，然后你可以在你的appdelegate中放入下面提到的条件。M文件在

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

    if ([[UIScreen mainScreen] bounds].size.height == 568)
        {

        self.ViewController = [[ViewController alloc] initWithNibName:@"ViewControlleriphone5" bundle:nil];
        }

        else
        {
             self.ViewController = [[ViewController alloc] initWithNibName:@"ViewControlleriphone4" bundle:nil];

        }

你可以在程序的任何地方使用它，这取决于你的需求，甚至在你的ViewController类中。最重要的是，您已经为iphone 4(320*480)和iphone 5(320*568)分别创建了两个xib文件。