我的代码在这里:
-(void)loadDataFromDisk
{
[dict release];
NSMutableData* data = [NSMutableData dataWithContentsOfFile:[self pathForDataFile]];
NSKeyedUnarchiver* unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
dict = [[unarchiver decodeObjectForKey:fileKey] retain];
[unarchiver finishDecoding];
[unarchiver release];
if(dict == NULL)
{
NSLog(@"First time in.");
dict = [[NSMutableDictionary alloc] init];
}
}
-(void)saveDataToDisk
{
NSMutableData* data = [NSMutableData data];
NSKeyedArchiver* archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver setOutputFormat:NSPropertyListBinaryFormat_v1_0];
// EncodeObject will automatically encode every primitive inside 'dictionaryToSave',
// As for objects, the object class must conform to NSCoding Protocol, else an error will occur.
[archiver encodeObject:dict forKey:fileKey];
[archiver finishEncoding];
[archiver release];
[data writeToFile:[self pathForDataFile] atomically:YES];
}
-(NSString*)pathForDataFile
{
NSArray* documentDir = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString* path = nil;
if (documentDir)
{
path = [documentDir objectAtIndex:0];
}
else
{
NSLog(@"error in [PersistentHandler pathForDataFile]");
}
// Returns 'directory'/data.bin to method(saveDatatoDisk/loadDataFromDisk)
return [NSString stringWithFormat:@"%@/%@", path, @"data.bin"];
}
如果我使用指定的 fileKey(即:“buttons”)保存一个文件一次,它会起作用。但是如果我想使用指定的 fileKey(即:“clocks”)将另一个文件保存到磁盘,它会覆盖“buttons”使用“时钟”,因此“无法再次访问按钮..
如何解决这个困境?我相信这应该是我“saveDataToDisk”(存档)的方式,我应该将一堆文件写入磁盘,而不是用最新的文件替换每个文件。