Upgrade to iOS 5

I'm iPhone developer. I want to upgrade my iphone 开发者_如何学JAVAto iOS 5. But I'don't know if I can run applications for iOS 4? Do I need to install new Xcode with new SDK?

You can install iOS 5 using the beta SDK, or you can go through iTunes Beta 10.5.

I am sure iOS 4 apps will run on the Beta iOS 5. You may run into some crashes depending on what frameworks your app uses versus what frameworks have changed. This is a great opportunity to test your apps against iOS 5 and correct any issues.

But keep in mind it is still a beta, and an early one at that.

You have to install the new beta sdk and then just install iTunes 10.5 beta and open iOS 5 beta file, it will open in iTunes and install on your device.

Yes..You need to get the latest SDK from the Apple developer portal with your username and password. You will also get the iTunes beta but that shouldn't be of much use as long you use the simulator to try stuff out; but if you have the developer access, use the device instead.