NSUserDefaults “Pause” / Crash on iOS8

问题

Ok, so I launched an app last week before iOS8 came out. Everything was working fine in iOS7 and below. But now since people have updated to iOS8 my app is pausing/crashing for no reason.

I came to terms that it is when I set an NSMutableArray to the NSUserDefaults, it pauses.

Please note, the NSMutableArray is an array of NSStrings.

BUT (this is weird) if I breakpoint skip through the code it works and I get no pause.

Here is the function that it is blowing up...

-(void)UpdateMyAgenda:(NSString*)SessionID Remove:(BOOL)Remove{

if(!Remove){
    //Do not Remove

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];


    _MyAgenda = [[NSMutableArray alloc]init];
    _MyAgenda = [prefs mutableArrayValueForKey:@"MyAgenda"];

    [_MyAgenda addObject:SessionID];

    [prefs setObject:_MyAgenda forKey:@"MyAgenda"];

    [prefs synchronize];

}else{
    //Remove

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

    _MyAgenda = [[NSMutableArray alloc]init];
    _MyAgenda = [prefs mutableArrayValueForKey:@"MyAgenda"];

    [_MyAgenda removeObject:SessionID];

    [prefs setObject:_MyAgenda forKey:@"MyAgenda"];

    [prefs synchronize];

}

for (NSString *item in _MyAgenda) {
    NSLog(@"%@", item);
}

NSLog(@"-----------");
}

回答1:

Ok so here is the deal, or a fix for now. It looks like setting a mutable array in the player prefs is breaking, but setting an NSArray is not.

So convert your array to a mutable one, add the object, then convert your mutable array to an nsarray and then set the user default.

Here is an example....

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    NSArray *arr = [prefs arrayForKey:@"MyAgenda"];

    _MyAgenda = [NSMutableArray arrayWithArray:arr];
    [_MyAgenda addObject:SessionID];

    arr = [NSArray arrayWithArray:_MyAgenda];

    [prefs setObject:arr forKey:@"MyAgenda"];
    [prefs synchronize];

来源：https://stackoverflow.com/questions/26029704/nsuserdefaults-pause-crash-on-ios8