cocoa

问题 I am using CoreText to render multiple columns of text. However, when I set the first letter of the 1st paragraph to a bold, larger font than the rest of the text, I incur 2 issues (both visible in the attached image): The spacing underneath the first line is too big (I understand that this is because the 1st character could be a g,y,p,q etc. Lines below the first line now do not line up with corresponding lines in the next column. Any advice on how to overcome these 2 issues would be greatly

问题 I have an NSSegmentedControl on my UI with 4 buttons. The control is connected to a method that will call different methods depending on which segment is clicked: - (IBAction)performActionFromClick:(id)sender { NSInteger selectedSegment = [sender selectedSegment]; NSInteger clickedSegmentTag = [[sender cell] tagForSegment:selectedSegment]; switch (clickedSegmentTag) { case 0: [self showNewEventWindow:nil]; break; case 1: [self showNewTaskWindow:nil]; break; case 2: [self toggleTaskSplitView

问题 The Problem I'm writing a Cocoa application and I want to raise exceptions that will crash the application noisily. I have the following lines in my application delegate: [NSException raise:NSInternalInconsistencyException format:@"This should crash the application."]; abort(); The problem is, they don't bring down the application - the message is just logged to the console and the app carries on it's merry way. As I understand it, the whole point of exceptions is that they're fired under

问题 I have a super view, which has 2 subviews. These subviews are overlapped. Whenever i choose a view from a menu, corresponding view should become the front view and handle actions. i.e., it should be the front most subview. acceptsFirstResponder resigns all work fine. But the mouse down events are sent to the topmost sub view which was set. Regards, Dhana 回答1: Here's another way to accomplish this that's a bit more clear and succinct: [viewToBeMadeForemost removeFromSuperview]; [self

问题 I have a super view, which has 2 subviews. These subviews are overlapped. Whenever i choose a view from a menu, corresponding view should become the front view and handle actions. i.e., it should be the front most subview. acceptsFirstResponder resigns all work fine. But the mouse down events are sent to the topmost sub view which was set. Regards, Dhana 回答1: Here's another way to accomplish this that's a bit more clear and succinct: [viewToBeMadeForemost removeFromSuperview]; [self

问题 I have a strange problem with NSTextView linewrapping after the 51st column if I enter a line of tabs. This only happens with tabs, not with any other character, which wrap correctly at the edge of the text view, not after the 51st character. This is easy to repeat. Create a blank project in XCode with a single window and just one NSTextView. The only non-default settings are that I have removed constraints, and used the old style autosize to autosize the textview so that it fills the window.

问题 I am trying to change the desktop image; the procedure I've come up with is below. The first time this code is run, the resized image is displayed on screen as wallpaper, but the next time there is no reaction. What am I doing wrong? -(IBAction)click:(id)sender { NSData *sourceData; NSError *error; NSFileManager *filemgr; filemgr = [NSFileManager defaultManager]; screenArray = [NSScreen screens]; screenCount = [screenArray count]; unsigned index = 0; for (index; index < screenCount; index++)

问题 I am trying to change the desktop image; the procedure I've come up with is below. The first time this code is run, the resized image is displayed on screen as wallpaper, but the next time there is no reaction. What am I doing wrong? -(IBAction)click:(id)sender { NSData *sourceData; NSError *error; NSFileManager *filemgr; filemgr = [NSFileManager defaultManager]; screenArray = [NSScreen screens]; screenCount = [screenArray count]; unsigned index = 0; for (index; index < screenCount; index++)

问题 I've created an string tokenizer like this: stringTokenizer = CFStringTokenizerCreate( NULL , (CFStringRef)str , CFRangeMake(0, [str length]) , kCFStringTokenizerUnitSentence , userLocale); But how do I obtain those sentences now from the tokenizer? The CF String Programming Guide doesn't mention CFStringTokenizer or tokens (did a full-text search in the PDF). 回答1: Here is an example of CFStringTokenizer usage: CFStringRef string; // Get string from somewhere CFLocaleRef locale =

问题 The gods have parachuted many habits into my isolated jungle village, such as: - (void) dealloc { [[NSNotificationCenter defaultCenter] removeObserver:self]; [super dealloc]; } Their ways are strange to me, yet I still seek to understand them. Why bother cleaning loose ends up if the instance is going away? Will the reference/retain count to that instance not be decremented? Will it clutter some sort of Notification Hash Table lurking out there that holds a list of all the listeners? 回答1: