UIButton - 只能在一個方向拉伸背景圖像？

Question

我有一個UIButton對象，我在其背景中使用可拉伸的圖像，所以我可以始終具有靈活的按鈕尺寸。

事情是我想有一個固定的圖像高度（比如32px），但想要一個更高的可觸摸區域（蘋果UI準則總是說至少44px高）。

如果我在x中有一個可拉伸的圖像，那麼它不幸的也延伸到y中。我想告訴圖像不要在y上伸展。這可能嗎？

[編輯]是的。回答我的問題：

Answer 1

所以，只是爲了幫助別人，我可以回答我的問題：

@interface StretchableXButton : UIButton 
{ 
    CGFloat imageHeight; 
} 
@property CGFloat imageHeight; // we need this later when we override an instance method 

+ (id)buttonWithFrame:(CGRect)frame; 

@end 

現在執行：

@implementation StretchableXButton 
@synthesize imageHeight; 

+ (id)buttonWithFrame:(CGRect)frame 
{ 
    StretchableXButton *button = [super buttonWithType:UIButtonTypeCustom]; 

    UIImage *normalImage = [UIImage imageNamed: @"ButtonBGNormal.png" ]; 
    UIImage *highlightedImage = [UIImage imageNamed:@"ButtonBGHighlighted.png" ]; 

    button.frame = frame; 
    button.imageHeight = normalImage.size.height; // we need him later in the method below 

    // make the images stretchable 
    normalImage = [normalImage stretchableImageWithLeftCapWidth:normalImage.size.width/2 topCapHeight:normalImage.size.height/2]; 
    highlightedImage = [highlightedImage stretchableImageWithLeftCapWidth:normalImage.size.width/2 topCapHeight:normalImage.size.height/2]; 

    button.backgroundColor = [UIColor clearColor]; 

    // SET OTHER BUTTON PROPERTIES HERE (textLabel, fonts, etc.) 

    [button setBackgroundImage:normalImage forState:UIControlStateNormal]; 
    [button setBackgroundImage:highlightedImage forState:UIControlStateHighlighted]; 

    return button; 
} 

// THIS IS THE TRICK. We make the height of the background rect match the image. 
-(CGRect)backgroundRectForBounds:(CGRect)bounds 
{ 
    CGRect bgRect = bounds; 
    bgRect.origin.y = (bounds.size.height - imageHeight)/2.0f; 
    bgRect.size.height = imageHeight; 

    return bgRect; 
} 


@end