cocoa-touch

问题 I push a view controller ( mainVC ) and add some subviews to it. Most of these views are built on-demand, as the user takes some action. When I build each view, I refer to mainVC.view.bounds to size the view. The ones that are built on demand size just fine, but the first one (which I add in viewDidLoad ) does not seem to account for either the hidden navigation bar or the unhidden toolbar - I'm not sure which. Other questions seem to assure me that viewDidLoad is the correct place to refer

问题 If you have any insight on this, it would also be nice to know whether there's a big latency between connections. 回答1: The Bluetooth protocol specifies that connections are point-to-point (hence the term "pairing"), but different profiles can be used concurrently with different stations. Each profile only supports one connection at a time. You can have a stereo headset connection with your car and a data connection with your laptop at the same time, but not multiple data connections.

问题 I can access the value like this: NSNumber* rotationZ = [myLayer valueForKeyPath:@"transform.rotation.z"]; But for some reason, if I try to KV-observe that key path, I get a compiler error. First, this is how I try to do it: [myLayer addObserver:self forKeyPath:@"transform.rotation.z" options:0 context:nil]; The compiler tells me: *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ addObserver: forKeyPath:@"rotation.z" options:0x0 context:0x528890] was sent to an

问题 I have an iPad app that receives data using UDP sockets. And it has a UIWebView to browse webpages. But while doing scroll in the UIWebView, everything freezes and no data is received. I've been searching and it has something to do with runloops and threads. But if the UIWebView can't run in another thread other than the main one, how can I receive data while doing scroll? It is critical to keep receiving data. The project uses the AsyncUdpSocket class from Cocoa AsyncSocket that works quite

问题 This is the current setup. I have the navigationController's toolbar with 5 buttons, and tapping on them hides the toolbar for 2 seconds, and then shows the toolbar again (except the 5th button - which brings up an actionsheet with buttons (ACTION & CANCEL)). On tapping on the 1-4 buttons, I do a self.navigationController.toolbarHidden = YES; and after exactly 2 seconds , I set the self.navigationController.toolbarHidden = NO; and this brings back the toolbar, and everything's fine. On

问题 I have a UITableView with custom cells. The cells containing one UITextView each and the cell is resizing during user type text in the TextView. My problem is when user is on first row in a TextView autocorrection bubbles wont be visible in the current cell. Is there any workaround or can someone point me to another direction? alt text http://img340.imageshack.us/img340/5414/skrmavbild20100519kl092.png 回答1: If the cell is resizing as the user types, you could set the minimum height of the

问题 I have noticed that with Xcode4 Apple has updated the application templates to include underscores before instance variables. // Xcode4 @property (nonatomic, retain) IBOutlet UIWindow *window; @synthesize window = _window; . // Xcode3 @property (nonatomic, retain) IBOutlet UIWindow *window; @synthesize window; I know there are differing opinions on the usefulness of this but I was just curious if the updated templates where: (1) Highlighting a new best practice. (2) Showing how Apple does

问题 I'm developing an iOs 4 app with latest SDK and XCode 4.2 I have a question about NSString parameters. This is my class definition: #import <Foundation/Foundation.h> @interface BlogEntry : NSObject { NSString* title; NSString* text; NSDate* date; NSString* photo; } - (id)initWithTitle:(NSString*)titulo text:(NSString*)texto date:(NSDate*)fecha photo:(NSString*)foto; @end And implementation: #import "BlogEntry.h" @implementation BlogEntry - (id)initWithTitle:(NSString*)titulo text:(NSString*

问题 I am sending out an email using the MFMailComposeViewController. MFMailComposeViewController* controller = [[MFMailComposeViewController alloc] init]; controller.mailComposeDelegate = self; [controller setSubject:@"subject"]; [controller setMessageBody:@"<a href=\"http://website.com\" target=\"_blank\">Link</a>." isHTML:YES ]; [self presentViewController:controller animated:YES completion:nil]; When the recipient opens this email in the default Mail app and taps the hyperlink, the page opens

问题 If the user have more than one keyboard on their iOS devices. Is this possible to force to pop the English keyboard? Thanks. 回答1: From Text Programming Guide for iOS, The input method and layout for the keyboard is determined by the user’s language preferences There is no way afaik to force the language programmatically. Setting the iPhone keyboard language Change language of keyboard Hope that helps! 回答2: To implement the language preferences of different users, iOS also supports different