cocoa-touch

问题 How to embed a Youtube video that has copyrighted content in it. For example when you try playing this video(http://www.youtube.com/embed/ADBKdSCbmiM) in a UIWebView it says This Video Contains content from Vevo. It is restricted from playback on certain sites How would I go about getting videos like this to play in an embedded player or a custom player that I would make using MPMoviePlayer or such. I know this is possible as following app does this. (http://itunes.apple.com/us/app/audioviz

问题 I have to update a small amount of text in a scrolling UITextView. I'll only be inserting a character where the cursor currently is, and I'll be doing this on a press of a button on my navigation bar. My problem is that whenever I call the setText method of the text view, it jumps to the bottom of the text. I've tried using contentOffset and resetting the selectedRange but it doesn't work! Here's my example: // Remember offset and selection CGPoint contentOffset = [entryTextView contentOffset

问题 I'm just starting out with Core Data and right now I'm building my data model. I need a UIColor attribute for my entity, but the type dropdown for the attribute doesn't have an option for this. Do I set it to Undefined or what? Thanks 回答1: What you probably want is a transformable attribute. Give the section on "Non-standard Persistent Attributes" in the Core Data Programming Guide an other read. A transformable attribute is, underneath the covers, a binary data attribute, but Core Data will

问题 I'm trying to do something I'd think would be fairly simple: Let a user input a dollar amount, store that amount in an NSNumber (NSDecimalNumber?), then display that amount formatted as currency again at some later time. My trouble is not so much with the setNumberStyle:NSNumberFormatterCurrencyStyle and displaying floats as currency. The trouble is more with how said numberFormatter works with this UITextField. I can find few examples. This thread from November and this one give me some

问题 I'm developing an iPhone application that makes heavy use of Core Data, primarily for its database-like features (such as the ability to set a sort order or predicate on fetch requests). I'm presenting all the data I fetch in various UITableViewControllers. What I'd like to know is a rough idea of how many objects I can fetch before it becomes a good idea to use an NSFetchedResultsController to handle the request. In the Core Data docs, it says that SQLite stores consider "10,000 objects to

问题 I'm developing an iPhone application that makes heavy use of Core Data, primarily for its database-like features (such as the ability to set a sort order or predicate on fetch requests). I'm presenting all the data I fetch in various UITableViewControllers. What I'd like to know is a rough idea of how many objects I can fetch before it becomes a good idea to use an NSFetchedResultsController to handle the request. In the Core Data docs, it says that SQLite stores consider "10,000 objects to

问题 I'm currently building a tabbed iPhone application where each tab's view controller is an instance of UINavigationController , and where every subcontroller of every one of the UINavigationController instances is an instance of UITableViewController . Ideally, I'd like to subclass UINavigationController so that the controller for each tab is a subclass of UINavigationController that (in addition to having all the standard UINavigationController functionality, obviously) serves as the

问题 I have a UIViewController that returns YES in shouldAutorotateToInterfaceOrientation: for UIDeviceOrientationPortrait and NO for everything else. With that view on the top of the stack, I use pushViewController:animated: to push a new UIViewController . The new controller returns YES for anything in shouldAutorotateToInterfaceOrientation: . The first view refuses to rotate (as expected). Once the second view is pushed, the user can rotate the device and the UI will rotate (also as expected).

问题 I read many articles about dynamic library usage including this page "Can you build dynamic library...". As apple document said, " Frameworks for iOS. iOS developers can now create dynamic frameworks. Frameworks are a collection of code and resources to encapsulate functionality that is valuable across multiple projects. Frameworks work perfectly with extensions, sharing logic that can be used by both the main application and the bundled extensions. ", see full page from here. Taking the

问题 This question already has answers here : KVO and ARC how to removeObserver (3 answers) In ARC do we need to send removeObserver: explicitly? (4 answers) Closed 6 years ago . Does adding an observer increase the retain count of an object? If yes, does ARC handle the removing of this observer too? If not, where should I remove the observer? 回答1: You should explicitly remove the observer even you use ARC . Create a dealloc method and remove there.. -(void)dealloc { [[NSNotificationCenter