如何在Xcode 3.2.3（iPhone SDK 4 beta）中启动iPhone 3.1.3项目

Question

I am having big problems since I downloaded the beta version of iPhone SDK 4.0. Okay, I just started to look at iPhone development a few weeks ago, but I cannot figure out how Xcode is supposed to work:

whenever I start a new project, I choose a template like "View-based application" or so. Now, the target will always (at least I did not find a preference anywhere!) be the latest SDK: 4.0. But then: switching the target back to, say, 3.1.3 the template files seem to contain errors! Starting an empty application this way yields an exception:

Terminating app due to uncaught exception 'NSUnknownKeyException', reason: [...] this class is not key value coding-compliant for the key rootViewController

Reason, it seems, is that the generated MainWindow.xib has a "referencing outlet" for rootViewController next to a viewController...

sick

Now, my (stupid) question: How do I develop an application NOT targeting the latest SDK, but the standard 3.1.3 SDK?? In other words: I would expect Xcode not only to ask for a project type in the New Project window, but also for my desired target platform to generate the correct templates!!

Am I right that the templates generated with this step are not valid for any other target than 4.0? How can that be??

...I want my Eclipse back! sigh

Can anybody help me please?

Answer 1

Just in case someone is looking for this.

Just check if the window responds to the function first. If it does (4.0 and greater), then use it, otherwise use the pre 4.0 version first.

if([self.window respondsToSelector:@selector(rootViewController)]) {
    self.window.rootViewController = self.viewController;        
} else {
    [self.window addSubview :self.viewController.view];        
}

Answer 2

Simple: don't use the beta SDK, which is intended at this stage for developing apps for an unreleased version of the OS, and about which you have agreed to a NDA.

So download the released version of the SDK, and be happy.

Answer 3

The resolution I found was to manually add my View to the Window in didFinishLaunchingWithOptions instead of relying on the Interface Builder connection. It seems that wiring up rootViewController w/iOS4 IB causes the app to crash when deployed to 3.x (3.1.3 for me).

So, first open IB, right click on Window, and make sure "rootViewController" isn't connected. Then in your AppDelegate, you should have something like

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [self.window addSubview:navigationController.view];
    [self.window makeKeyAndVisible];

    return YES;
}

This is for if your main view is a navigationController; if it's not, change addSubview accordingly.

Answer 4

The answer to the question I was looking for seems to be:

It is not possible.

To develop for a certain iOS release, install the appropriate Xcode. Apple apparently does not know people who want to develop for multiple target platforms at once. :-(

Answer 5

I think Francois has a great answer.

I am also new to Xcode and was working through various tutorials using Xcode 3.2.6 and testing on iOS 3.1.3 device. The tutorials were for iOS 4.3, which all start by selecting a "View-based application." When I tested the tutorials they worked in the simulator but not on the device. I assume this is true for SDK 4 but I haven't tried it myself.

I first received the error:"...specifies a minimum OS version of 4.3, which is too high to be installed on iPhone."

Many other people have addressed this but it is fixed by going to Project>Edit Project Settings, selecting the Build tab, scrolling down to the Deployment section and changing the field "Development Target iOS" to be the same as the iOS on the device.

Then the tutorial apps would launch on the phone but only a blank screen would show and I got the error: “SIGABRT” and "NSException" - even when I just tried to launch a simple HelloWorld app. This was caused by the self.window.rootViewController = self.viewController not being supported by iOS 3.

To fix it go to the ___Delegate.m file and replace the line "self.window.rootViewController = self.viewController" with Francois' elegant solution:

 if([self.window respondsToSelector:@selector(rootViewController)]) {
    self.window.rootViewController = self.viewController;        
} else {
    [self.window addSubview :self.viewController.view];        
}

Now the View-based application template in SDK 3.2 works for iOS 3 and 4.