cocoa-touch

问题 In UIViewController's documentation, Apple suggests calling the super at some point in the implementation of viewWillAppear, viewDidAppear, viewWillDisappear, viewDidDisappear, etc... For example, the discussion on viewDidDisappear is: You can override this method to perform additional tasks associated with dismissing or hiding the view. If you override this method, you must call super at some point in your implementation . My question is does it matter when the super method is called and, if

问题 In UIViewController's documentation, Apple suggests calling the super at some point in the implementation of viewWillAppear, viewDidAppear, viewWillDisappear, viewDidDisappear, etc... For example, the discussion on viewDidDisappear is: You can override this method to perform additional tasks associated with dismissing or hiding the view. If you override this method, you must call super at some point in your implementation . My question is does it matter when the super method is called and, if

问题 In UIViewController's documentation, Apple suggests calling the super at some point in the implementation of viewWillAppear, viewDidAppear, viewWillDisappear, viewDidDisappear, etc... For example, the discussion on viewDidDisappear is: You can override this method to perform additional tasks associated with dismissing or hiding the view. If you override this method, you must call super at some point in your implementation . My question is does it matter when the super method is called and, if

问题 The documentation is rather poorly written when talking about playing audio in the background. It gives the impression that all you have to do to continue playing the audio that you are currently playing is to just add a key/value pair to the info.plist file and wallah, it's magic. However, this is not the case. For instance, if I play an mp3 that is 2 minutes long, obviously the audio is long enough to be able to play after I hit the home button to send my app to the background. The thing is

问题 I've an app which provides to the user some sort of a line graph. I'm using an UIScrollView which is containing the view with graph. The view is using CoreGraphics to draw the graph in it's drawrect method. The problem arises when the graph gets too long. Scrolling through the graph seems to stutter and eventually the app would run out of memory and exit. Looking around at other apps I see the guys who created the WeightBot app were able to manage long ongoing graphs without any problems so

问题 String value not converting to date format. see my code below... { NSString * TempDate = [NSString stringWithFormat:@"%@ %@ %@",Datelbl.text,yearString,TimeLbl.text]; // result is Thursday, November 21 2013 3:05 PM NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat : [NSDateFormatter dateFormatFromTemplate:@"EEEE, MMMM d yyyy hh:mm a" options:0 locale:[NSLocale currentLocale]]]; AppointmentDate = [dateFormatter dateFromString:TempDate];// in .h file

问题 I would like to get rid of the "return" function of the keyboard while the user is typing, so there are no new lines, so instead I would like the 'return' key to function as 'Done' so it would hide the keyboard. I am using a UITextView, that is editable, so the user is able to type their post, and post it to the main timeline, but since I have fixed cells, I don't want the user to be able to press 'return' and their post would be out of range of the timeline. I found this that works with

问题 This question already has answers here : UICollectionView registerClass: forCellWithReuseIdentifier method breaks UICollectionView (2 answers) Closed 6 years ago . I'm trying to get a UICollectionView working in my application and for some reason I keep getting a sigabrt. The error I am getting is * Assertion failure in -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:] I have googled around, and it seems like most of the time this is related to the neglecting to

问题 Has anyone been successful showing the standard Apple MFMailComposeViewController from a UIModalPresentationStyleFormSheet view controller on the iPad? When I do this the view shows as expected but when the user taps any of the input text views, the subject for example, and the keyboard slides pressing the Cancel button will show the "Delete Draft" & "Save Draft" popover outside of the screen bounds. If I change the modal view to full screen it works properly. 回答1: I don't think you are

问题 I know there has been a lot of discussion around fast scrolling. Apple provides excellent examples: http://developer.apple.com/library/ios/#samplecode/TableViewSuite/Introduction/Intro.html I will have a custom UITableViewCell that has 2 UIImageView's and 3 UILabels as subviews. If I just add them as subviews to the content view will my scrolling be slow? Would it be best to just draw these? 回答1: The answer I got from the UIKit guys at WWDC this year was "it kinda depends on what you're doing