无法从plist加载数组，也无法获取对象

Question

Im trying to save a score (NSNumber) into a plist file and then load it. This is my save method:

- (void)saveScore:(int)iScore;
{
    NSMutableData *data = [[NSMutableData alloc] init];
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    NSNumber *score=[NSNumber numberWithInt:iScore];

    [archiver encodeObject:[NSArray arrayWithObject:score]];
    [archiver finishEncoding];
    [data writeToFile:[self dataFilePath] atomically:YES];

}

which i checked and it saves the data into the file.

this is my load method:

-(void)LoadData{

    NSString *filePath = [self dataFilePath];
    if ([[NSFileManager defaultManager] fileExistsAtPath:filePath])
    {
        NSMutableArray *array = [[NSMutableArray alloc] initWithContentsOfFile:filePath];
        NSNumber * number= ((NSNumber *)[array objectAtIndex:0]);
        int score=[number intValue];
    }
}

i checked and the dataFilePath returns the right path. but the array don't get any items.

Answer 1

If you use an NSKeyedArchiver to create a file, you need to use an NSKeyedUnarchiver to read the file back in.

If you want to use [[NSMutableArray alloc] initWithContentsOfFile:... to read the file in then you should save the array to file using [data writeToFile:path atomically:YES];