iphone - 核心数据 : sorting before saving

Question

我正在向一个简单的实体添加一个名称列表(来自数组)。但在保存实体之前，我希望对它们进行排序。请哪位好心人告诉我该怎么做？

我见过如何对一些获取的数据进行排序，但我不知道该怎么做。一个书面的例子将不胜感激。非常感谢。

NSManagedObjectContext *context = [self managedObjectContext];
NSString *myTempString;

for (databaseMakerVC *aName in peoplesNames.theArray) {
    myTempString = [[NSString alloc] initWithFormat:@"%@", aName];

    peoplesNamesObject *newObject = [NSEntityDescription
                                     insertNewObjectForEntityForName:@"peoplesNamesObject"
                                     inManagedObjectContext:context];
    newObject.aName = myTempString;
}


    // *** Do the sorting here!? ***


// Save the context
NSError *error = nil;
if (![context save:&error]) {
    NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}

Answer 1

 NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription 
                                   entityForName:@"peoplesNamesObject" inManagedObjectContext:context];

 [fetchRequest setEntity:entity];


     NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"aName" ascending:YES]; 

        NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor]; 

        [fetchRequest setSortDescriptors:sortDescriptors]; 

        NSError *error;


       NSArray *array=[context executeFetchRequest:fetchRequest error:&error]; 

这会起作用