我对Objective-C和iOS编程还比较陌生,遇到了一个奇怪的错误。所涉及的应用程序使用一个自定义类型的NSMutableArray进行初始化,该类型是使用NSObject创建的。应用程序可操作此数组。如果在应用程序运行期间添加新值,则使用NSUserDefaults保存这些值,并在下次打开应用程序时从NSUserDefaults中获取这些值以及默认值。
以下是出现的错误:
Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<__NSCFConstantString 0xb404> valueForUndefinedKey:]: this class is not key value coding-compliant for the key score.'
*** First throw call stack:
(0x1c9b012 0x10d8e7e 0x1d23fb1 0xb84d1d 0xaf100b 0xaf0fbd 0xb0f247 0xb3023c 0xb30056 0x3e40 0x3c5f 0x11f5ad 0x10ec705 0x202c0 0x20258 0x242ff4 0x10ec705 0x202c0 0x20258 0xe1021 0xe157f 0xe1056 0x246af9 0x10ec705 0x202c0 0x20258 0xe1021 0xe157f 0xe06e8 0x4fcef 0x4ff02 0x2dd4a 0x1f698 0x1bf6df9 0x1bf6ad0 0x1c10bf5 0x1c10962 0x1c41bb6 0x1c40f44 0x1c40e1b 0x1bf57e3 0x1bf5668 0x1cffc 0x290d 0x2835)
libc++abi.dylib: terminate called throwing an exception
我不确定错误是什么,也不知道如何进行调试。
之前这段代码运行得非常顺利,我的做法只是从默认预设元素列表中删除了一两个元素,然后在模拟器中模拟删除应用程序并重新编译代码。自那以后,我的程序就会崩溃,并出现以上所述的错误信息,我不知道该如何修复它。
如果有人能帮助我解决这个问题,那将是非常棒的。我可以根据需要附上代码,但我不确定哪些代码是相关的,而且可能太多了,无法在项目中全部发布。
以下是编码和解码我自定义名称NSObject类名为name.h属性的代码:
-(void)encodeWithCoder:(NSCoder *)encoder
{
[encoder encodeObject:self.name forKey:@"name"];
[encoder encodeInteger:self.score forKey:@"score"];
}
-(id)initWithCoder:(NSCoder *)decoder
{
if((self = [super init]))
{
self.name = [decoder decodeObjectForKey:@"name"];
self.score = [decoder decodeIntegerForKey:@"score"];
}
return self;
}
从类中检索数据,如果这很重要,那么这段代码出现在appdelegate.m中:
NSData *data = [[NSUserDefaults standardUserDefaults] objectForKey:@"dataArray"];
NSInteger score = 0;
NSMutableArray *temp = [[NSMutableArray alloc] initWithObjects:@"name", nil];
NSMutableArray *tempList = [[NSMutableArray alloc] init];
for(NSString *y in temp)
{
Name *name = [[Name alloc] init];
name.name = y;
name.score = score;
[tempList addObject:name];
}
if (data)
{
NSArray *list = [NSKeyedUnarchiver unarchiveObjectWithData:data];
NSMutableArray *names = [[NSMutableArray alloc]initWithArray:list];
// [_nameList addObjectsFromArray:temp];
NSMutableArray *t = [[names arrayByAddingObjectsFromArray:tempList ] mutableCopy];
_nameList = [[NSMutableArray alloc]init];
[_nameList addObjectsFromArray:t];
}
else
{
//First time load or data is not saved yet
_nameList = [[NSMutableArray alloc] initWithObjects:@"name", nil];
}
在关闭时保存数组:
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
NSData *data =[NSKeyedArchiver archivedDataWithRootObject:_nameList];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:@"dataArray"];
}
同样的代码也在applicationDidEnterBackground中。
按'score'排序的代码。
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController: (UIViewController *)viewController
{
if(viewController == _viewController3)
{
[self sortNames:_nameList];
[[(ThirdViewController*)_viewController3 topList] reloadData];
}
}
-(void)sortNames:(NSMutableArray*)test
{
NSArray* temp = [[NSArray alloc] initWithArray:test];
NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"score" ascending:NO];
NSArray *sortedLinks = [[temp sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]] mutableCopy];
_nameList = (NSMutableArray*) sortedLinks;
}