iOS How to change subviews' properties?

- (id)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {

		NSArray *keyboards = [[NSBundle mainBundle] loadNibNamed:@"ChineseRhymeKeyboard" owner:self options:nil];
		self = [[keyboards objectAtIndex:0] retain];	
		
		for (UIButton *button in self.subviews) {
//			CGRect frame = button.frame;
//			frame.origin.y -= 10;
//			button.frame = frame;
//			[self addSubview:button];
			NSLog(@"%@", button.titleLabel.text);
		}
    }
	
    return self;
}

for (int i = 0; i < 4; i++) {
	UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
	button.frame = CGRectMake(0.0, 0.0, KEY_WIDTH, KEY_HEIGHT);
	button.center = CGPointMake(KEY_X1 + KEY_WIDTH / 2, KEY_Y + KEY_HEIGHT * (2 * i + 1) / 2 + KEY_GAP_Y * i);
	button.tag = (i + 1) * 100;
			
	if (i == 0) {
		button.enabled = NO;
		button.highlighted = YES;
	}
			
	[button setTitle:[fourVoice objectAtIndex:i] forState:UIControlStateNormal];
	[button addTarget:self action:@selector(selectFourVoice:) forControlEvents:UIControlEventTouchUpInside];

	[self addSubview:button];
}

-(IBAction) selectFourVoice:(id)sender {
	UIButton *fourVoice = nil;
	
	for (int i = EvenTone; i <= 400; i+=100) {
		fourVoice = (UIButton *)[self viewWithTag:i];
		
		fourVoice.enabled = YES;
		fourVoice.highlighted = NO;
	}
	
	fourVoice = (UIButton *)sender;
	
	for (int i = 1; i <= 4; i++) {
		for (int j = 1 + 100 * i; j <= 100 * i + 10; j++) {
			UIButton *key = (UIButton *)[self viewWithTag:j];
			
			[self setKeyTitle:key forTone:fourVoice.tag];
		}
	}

	fourVoice.highlighted = YES;
	fourVoice.enabled = NO;
}