YouTipIos Universal Applications
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## Introduction
A universal application is an app designed for both iPhone and iPad in a single binary file. This helps with code reuse and enables faster updates.
### Example Steps
1. Create a simple View-based application.
2. On the right side of the file viewer, rename the file `ViewController.xib` to `ViewController_iPhone.xib`, as shown below:
3. Select "File -> New -> File...", then choose User Interface, select View, and click Next:
4. Choose iPad as the device and click Next:
5. Save this file as `ViewController_iPad.xib`, then select Create.
6. Add a label to the center of the screen in both `ViewController_iPhone.xib` and `ViewController_iPad.xib`.
7. In `ViewController_iPhone.xib`, select the Identity Inspector and set the custom class to `ViewController`:
8. Update the `application:didFinishLaunchingWithOptions:` method in `AppDelegate.m`:
```objective-c
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [ initWithFrame:[ bounds]];
// Override point for customization after application launch.
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
self.viewController = [ initWithNibName:@"ViewController_iPhone" bundle:nil];
} else {
self.viewController = [ initWithNibName:@"ViewController_iPad" bundle:nil];
}
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}
```
9. In the project summary, update the Devices setting to "universal," as shown below:
### Output
When you run this application, you will see the following output:
Running the application on the iPad simulator produces the following output:
