點擊按鈕時顯示圖像？

Question

我有3個按鈕代表3個不同的圖像。只要輕按按鈕，圖像就會顯示出來。我的問題是，如何使用if（）和NSArray/NSMutableDictionary/UIButton標籤或其他方法來縮短代碼。

- (id)initWithFrame:(CGRect)frame 
{ 
    _button1 = [UIButton buttonWithType:UIButtonTypeCustom]; 
    _button1.frame = CGRectMake(20, 250, 50, 50); 
    [_button1 addTarget:self action:@selector(button1Tapped) forControlEvents:UIControlEventTouchUpInside]; 
    [self addSubview:_button1]; 

    _button2 = [UIButton buttonWithType:UIButtonTypeCustom]; 
    _button2.frame = CGRectMake(140, 250, 50, 50); 
    [_button2 addTarget:self action:@selector(button2Tapped) forControlEvents:UIControlEventTouchUpInside]; 
    [self addSubview:_button2]; 

    _button3 = [UIButton buttonWithType:UIButtonTypeCustom]; 
    _button3.frame = CGRectMake(210, 250, 50, 50); 
    [_button3 addTarget:self action:@selector(button3Tapped) forControlEvents:UIControlEventTouchUpInside]; 
    [self addSubview:_button3]; 
} 

- (void)button1Tapped 
{ 
    UIImage *_image = [UIImage imageNamed:@"IMAGE_1"]; 
    _imageView = [[UIImageView alloc] initWithImage:_image]; 
    _imageView.frame = CGRectMake(0, 0, 256, 384);   
    [self addSubview:_imageView]; 
} 

- (void)button2Tapped 
{ 
    UIImage *_image = [UIImage imageNamed:@"IMAGE_2"]; 
    _imageView = [[UIImageView alloc] initWithImage:_image]; 
    _imageView.frame = CGRectMake(0, 0, 256, 384);   
    [self addSubview:_imageView]; 
} 

- (void)button3Tapped 
{ 
    UIImage *_image = [UIImage imageNamed:@"IMAGE_3"]; 
    _imageView = [[UIImageView alloc] initWithImage:_image]; 
    _imageView.frame = CGRectMake(0, 0, 256, 384);   
    [self addSubview:_imageView]; 
} 

謝謝。

Answer 1

設置像這樣的圖像數組。讓它成爲你班級的一個財產。另外，也儘早建立你的圖像視圖。

@property(nonatomic, strong) NSArray *images; 
@property(nonatomic, strong) UIImageView *imageView; 

- (id)initWithFrame:(CGRect)frame { 

    self.images = [NSArray arrayWithObjects:[UIImage imageNamed:@"IMAGE_1"], [UIImage imageNamed:@"IMAGE_2"], [UIImage imageNamed:@"IMAGE_3"], nil]; 

    _imageView = [[UIImageView alloc] initWithImage:[self.images objectAtIndex:0]]; 
    _imageView.frame = CGRectMake(0, 0, 256, 384);   
    [self addSubview:_imageView]; 
} 

在創建按鈕，給他們這樣的標籤...

_button1.tag = 1; 
_button2.tag = 2; 
_button3.tag = 3; 

而且在創建按鈕的時候，讓他們都使用自來水一樣選擇...

[_button1 addTarget:self action:@selector(buttonTapped) forControlEvents:UIControlEventTouchUpInside]; 
[_button2 addTarget:self action:@selector(buttonTapped) forControlEvents:UIControlEventTouchUpInside]; 
// etc 

在水龍頭上，標籤1將成爲數組索引...

- (void)buttonTapped:(id)sender { 

    NSUInteger tag = ((UIButton *)sender).tag; 
    UIImage *image = [self.images objectAtIndex:tag]; 
    self.imageView.image = image; 
}