如何在数组中存储uibuttons?

我有一个方法系在四个按钮上。我想创建一个包含每个按钮的数组,然后从数组中检索和交互w/a按钮。我在下面修改的代码。当我试图从数组中获取一个按钮并向它发送一条消息时,它会变得非常好。

有没有想过我做错了什么?

hack-dumpview控制器.h

#import <UIKit/UIKit.h>

@interface Hack_DumpViewController : UIViewController {
    IBOutlet UIButton *redButton;
    IBOutlet UIButton *greenButton;
    IBOutlet UIButton *blueButton;
    IBOutlet UIButton *yellowButton;    
    NSArray *buttonMapping; 
}

- (IBAction) changeToYo:(id)sender;
@property (nonatomic, retain) UIButton *redButton;
@property (nonatomic, retain) UIButton *greenButton;
@property (nonatomic, retain) UIButton *blueButton;
@property (nonatomic, retain) UIButton *yellowButton;
@property (nonatomic, retain) NSArray *buttonMapping;   


@end

hack-dumpview控制器.m

#import "Hack_DumpViewController.h"

@implementation Hack_DumpViewController

@synthesize redButton;
@synthesize greenButton;
@synthesize yellowButton;
@synthesize blueButton;
@synthesize buttonMapping;

- (IBAction) changeToYo:(id)sender {
    NSLog(@"changing numbers!");
    for (UIButton *b in buttonMapping) {
        [b setTitle:@"yo!"];
    }
    NSLog(@"changed to numbers!");
}


- (void)viewDidLoad {
buttonMapping = [[NSArray alloc] initWithObjects:greenButton, redButton, yellowButton, blueButton, nil];    
}