Why I often got ExcBadAccess in this code: - c++

Question

I uses ARC
NSAttributedString * arString = [self asSchedule:arTimes];
self.lblTimeLeft.attributedText = arString;
Not much information is given. It goes straight to main
int main(int argc, char *argv[])
{
#autoreleasepool {
//int retVal = UIApplicationMain(argc, argv, nil, nil);
int retVal = UIApplicationMain(argc, argv, nil, NSStringFromClass([newIsiKotaAppDelegate class]));
return retVal;
}
}
I manage to spot that the last code executed is this:
self.lblTimeLeft.attributedText = arString;
I provided additional code to test things out
NSAttributedString * arString = [self asSchedule:arTimes];
self.lblTimeLeft.attributedText = arString;
PO1(#"Hello World");
while(false);// Error happen after this code is executed
}
The code is part of the routine that provides UITableViewCell to display. So error happen after
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSUInteger row = indexPath.row;
NSDictionary * rowDictionary = _marManagedObjectArray [row];
BGCinemaScheduleCell * BCS = [[BGCinemaScheduleCell alloc]init];
BCS.dicCinemaDictionary =rowDictionary;
return BCS; //This is where the error happen
}
It seems that the NSAttributedString works fine till it's actually displayed or something.
The error seems to happen on
TAttributes::TAttributes(__CFDictionary const *)
The content of asSchedule is usual
-(NSAttributedString *) asSchedule:(NSArray *) arTimes
{
NSMutableArray * timeBefore = [NSMutableArray array];
NSMutableArray * timeAfter = [NSMutableArray array];
for (NSString * strTime in arTimes) {
NSDate * date = [NSDate dtWithCurrentDateAndProvidedTime: strTime];
NSTimeInterval dblInterval =[date timeIntervalSinceNow];
if (dblInterval>0)
{
[timeAfter addObject:strTime];
}
else{
[timeBefore addObject:strTime];
}
}
NSString * strTimeBefore = [timeBefore componentsJoinedByString:#" "];
NSString * strTimeAfter = [timeAfter componentsJoinedByString:#" "];
NSString *yourString = [NSString stringWithFormat:#"%# %#", strTimeBefore, strTimeAfter];
// start at the end of strTimeBefore and go the length of strTimeAfter
NSRange boldedRange = NSMakeRange([strTimeBefore length] + 1, [strTimeAfter length]);
NSString *boldFontName = [[UIFont boldSystemFontOfSize:12] fontName];
NSMutableAttributedString *attrString = [[NSMutableAttributedString alloc] initWithString:yourString];
[attrString addAttribute:NSFontAttributeName value:boldFontName range:boldedRange];
PO1(NSStringFromRange(boldedRange));
PO1(#(attrString.length));
return attrString;
}
Update:
I changed self.lblTimeLeft.attributedText = arString; to self.lblTimeLeft.attributedText = arString.copy; to no avail.
I wonder if this could be the problem:
[attrString addAttribute:NSFontAttributeName value:boldFontName range:boldedRange];
I think the original sample use KCFont something instead of NSFontAttributeName

Answer 1

You were almost there:
I wonder if this could be the problem: [attrString addAttribute:NSFontAttributeName value:boldFontName range:boldedRange];
Your code says:
NSString *boldFontName = [[UIFont boldSystemFontOfSize:12] fontName];
...
[attrString addAttribute:NSFontAttributeName value:boldFontName range:boldedRange];
It should say:
UIFont *boldFont = [UIFont boldSystemFontOfSize:12];
...
[attrString addAttribute:NSFontAttributeName value:boldFont range:boldedRange];
According to Table 1 of the docs (link below) and my own app code, you should be passing an NSFont not a font name.
https://developer.apple.com/library/ios/documentation/cocoa/Conceptual/AttributedStrings/Articles/standardAttributes.html#//apple_ref/doc/uid/TP40004903-SW2

Answer 2

Can't tell from the code whether your project uses ARC or not, but it looks like your asSchedule method returns a string with a refcount of 0. It's up to you to retain a reference to that string, either old-school using the retain keyword (probably a bad idea) or by assigning it to a property declared with the strong keyword (or retain, if pre-ARC).
The best tool for debugging this stuff is Instruments, using the Zombies inspection. If I am right that you are trying to use the string after its refcount hits 0 and the memory has been released, you'll see the history of refcount increments and decrements pretty clearly.

Answer 3

Try alloc and initing the Attributedstring and then assign it to the self.lblTimeLeft.attributedText