NSUserDefaultsに保存しても問題はありませんが、プロパティをディスクに保存する場合は、.plistファイルに保存して後で取得するためのコードをまとめました。この要点でも見つけることができます。
保存
// We're going to save the data to SavedState.plist in our app's documents directory
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *plistPath = [rootPath stringByAppendingPathComponent:@"SavedState.plist"];
// Create a dictionary to store all your data
NSMutableDictionary *dataToSave = [NSMutableDictionary dictionary];
// Store any NSData, NSString, NSArray, NSDictionary, NSDate, and NSNumber directly. See "NSPropertyListSerialization Class Reference" for more information.
NSString *myString = @"Hello!"
[dataToSave setObject:myString forKey:@"MyString"];
// Wrap primitives in NSValue or NSNumber objects. Here are some examples:
BOOL someBool = YES;
NSNumber *boolValue = [NSNumber numberWithBool:someBool];
[dataToSave setObject:boolValue forKey:@"SomeBoolValue"];
int someInteger = 99;
NSInteger *integerValue = [NSNumber numberWithInteger:someInteger];
[dataToSave setObject:integerValue forKey:@"SomeIntegerValue"];
// Any objects that conform to NSCoding can be archived to an NSData instance. In this example, MyClass conforms to NSCoding.
MyClass *someObject = [[MyClass alloc] init];
NSData *archivedStateOfSomeObject = [NSKeyedArchiver archivedDataWithRootObject:someObject];
[dataToSave setObject:archivedStateOfSomeObject forKey:@"SomeObject"];
// Create a serialized NSData instance, which can be written to a plist, from the data we've been storing in our NSMutableDictionary
NSString *errorDescription;
NSData *serializedData = [NSPropertyListSerialization dataFromPropertyList:dataToSave
format:NSPropertyListXMLFormat_v1_0
errorDescription:&errorDescription];
if(serializedData)
{
// Write file
NSError *error;
BOOL didWrite = [serializedData writeToFile:plistPath options:NSDataWritingFileProtectionComplete error:&error];
NSLog(@"Error while writing: %@", [error description]);
if (didWrite)
NSLog(@"File did write");
else
NSLog(@"File write failed");
}
else
{
NSLog(@"Error in creating state data dictionary: %@", errorDescription);
}
読み込み中
// Fetch NSDictionary containing possible saved state
NSString *errorDesc = nil;
NSPropertyListFormat format;
NSString *plistPath;
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES) objectAtIndex:0];
plistPath = [rootPath stringByAppendingPathComponent:@"SavedState.plist"];
NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:plistPath];
NSDictionary *unarchivedData = (NSDictionary *)[NSPropertyListSerialization
propertyListFromData:plistXML
mutabilityOption:NSPropertyListMutableContainersAndLeaves
format:&format
errorDescription:&errorDesc];
// If NSDictionary exists, look to see if it holds a saved game state
if (!unarchivedData)
{
NSLog(@"Error reading plist: %@, format: %d", errorDesc, format);
}
else
{
// Load property list objects directly
NSString *myString = [unarchivedData objectForKey:@"MyString"];
// Load primitives
NSNumber *boolValue = [unarchivedData objectForKey:@"SomeBoolValue"];
BOOL someBool = [boolValue boolValue];
NSNumber *integerValue = [unarchivedData objectForKey:@"SomeIntegerValue"];
BOOL someBool = [integerValue integerValue];
// Load your custom objects that conform to NSCoding
NSData *someObjectData = [unarchivedData objectForKey:@"SomeObject"];
MyClass *someObject = [NSKeyedUnarchiver unarchiveObjectWithData:someObjectData];
}
詳細については、アーカイブおよびシリアル化プログラミングガイドを参照してください。