UILabel不昏暗的按鈕

Question

我有一個編程生成的UIButton與標籤屬性和背景圖像。點擊後，背景圖像變灰，但文字不變。我如何讓標籤也指明它何時被點擊？

按照要求，我的按鈕代碼：

#import "BCB.h" 
@implementation BCB 
@synthesize cardText; 
- (id)initWithFrame:(CGRect)frame 
{ 
    self = [super initWithFrame:frame]; 
    if (self) 
    { 
     [self setFrame:frame]; 
     cardText = cardText = [[MyLabel alloc] 
           initWithFrame:(CGRect){8, 8, 144, 186}]; 
     cardText.numberOfLines = 0; 
     cardText.font = [UIFont fontWithName:@"Helvetica" size:18.0]; 
     cardText.textColor = [UIColor whiteColor]; 
     cardText.backgroundColor = [UIColor clearColor]; 
     cardText.lineBreakMode = NSLineBreakByWordWrapping; 
     [self addSubview:cardText]; 
     [self setBackgroundImage:[UIImage imageNamed:@"BC" ] forState:UIControlStateNormal]; 
    } 
    return self; 
} 
@end 

而且MyLabel代碼：

#import "MyLabel.h" 
@implementation MyLabel 
// Helper function to actually set the text. 
- (void)reallySetText:(NSString*)text 
{ 
    [super setText:text]; 
} 
// Function to top align text within a label. 
- (void)topAlign 
{ 
    // Get the size of the text box containing the label with its current font and size. 
    CGSize textSize = [self.text sizeWithFont:self.font 
          constrainedToSize:(CGSize){self.frame.size.width, self.frame.size.height} 
           lineBreakMode:NSLineBreakByWordWrapping]; 
    // Trim the frame up to exactly fit the text. 
    self.frame = (CGRect){self.frame.origin.x, self.frame.origin.y, textSize.width, textSize.height}; 
} 
// Shrink font until it fits the provided frame. 
CGFloat maxSizeThatFitsFrame(MyLabel* labelCopy, CGFloat fontSize, CGRect rect) 
{ 
    while (labelCopy.frame.size.height > rect.size.height && fontSize > 4.0f) 
    { 
     fontSize -= 0.5f; 
     labelCopy.font = [UIFont fontWithName:@"Helvetica" size:fontSize]; 
     [labelCopy topAlign]; 
    } 
    return fontSize; 
} 
// Overloading the drawTextInRect method to topAlign the text as well. 
-(void)drawTextInRect:(CGRect)rect 
{ 
    [super drawTextInRect:rect]; 
    [self topAlign]; 
} 
// Function to set the label to have the provided text within the provided rectangle with the provided initial font size. 
- (void)setText:(NSString *)text inFrame:(CGRect)rect withFontSize:(CGFloat)fontSize andColor:(UIColor*)color 
{ 
    // Set the text. 
    [super setText:text]; 
    // Set the frame. 
    [self setFrame:rect]; 
    // Make a copy of the label. 
    MyLabel* labelCopy = [[MyLabel alloc] 
          initWithFrame: 
          (CGRect){ 
           self.frame.origin.x, 
           self.frame.origin.y, 
           self.frame.size.width, 
           self.frame.size.height+240}]; 
    // Make the text wrap properly. 
    labelCopy.numberOfLines = 0; 
    labelCopy.lineBreakMode = NSLineBreakByWordWrapping; 
    // Set the copy's text. 
    [labelCopy reallySetText:self.text]; 
    // Set the copy's font. 
    labelCopy.font = [UIFont fontWithName:@"Helvetica" size:fontSize]; 
    // Top align the copy. 
    [labelCopy topAlign]; 
    // If the copy's height is larger than the rectangle's height, resize it until it fits. 
    if (labelCopy.frame.size.height > rect.size.height) 
    { 
     fontSize = maxSizeThatFitsFrame(labelCopy, fontSize, rect); 
    } 
    // Set the label's font to a size that fits. 
    [self setFont:[UIFont fontWithName:@"Helvetica" size:fontSize]]; 
    // Set the label's color. 
    self.textColor = color; 
    // Make the text wrap properly. 
    self.numberOfLines = 0; 
    self.lineBreakMode = NSLineBreakByWordWrapping; 
    // Top align the label. 
    [self topAlign]; 
} 
@end 

Answer 1

呼叫setTitleColor:forState:爲UIControlStateHighlighted。 Docs.

Answer 2

看看這兩個類似的問題。他們一定會解決您的疑問：

Question 1

Question 2

這裏有一件事嘗試：

可以爲UIButtonUIControlStateHighlighted狀態添加目標像

[button addTarget:self action:@selector(buttonHighlighted:) forControlEvents:UIControlStateHighlighted]; 

和在buttonHighlighted方法中，您可以更改標籤的顏色的文字

- (void) buttonHighlighted:(id)sender 
{ 
    //code to change the color of your Label subview... 
} 

希望這有助於