iphone - 具有图像和标题的 UIToolbar UIBarButtonItem 的文本非常暗淡

Question

我的 iPhone View 在其工具栏中添加了一些自定义按钮。每个按钮都有图像和文本标题，创建方式如下:

UIBarButtonItem *fooButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"foo.png"] style:UIBarButtonItemStylePlain target:self action:@selector(fooButtonPressed:)];
fooButton.title=@"Foo";

标题文字显示非常暗淡；看起来它的 alpha 约为 0.5。如果我使用默认的 UIToolBar barStyle，我根本无法读取文本。使用 UIBarStyleBlack 时，我可以阅读文本，但它看起来仍然很暗淡。

我也尝试过initWithTitle，然后设置image属性；结果是相同的。

有没有办法让文字变亮？我希望外观类似于 UITabBar，其项目既有图像又有标题。

感谢您的帮助!

Answer 1

我试图使用 UIBarButtonItem 来显示图像和按钮，但我很确定它已锁定以显示其中一个或另一个。使用this thread中的基本思想我想出了一个使用 UIButton 和背景图像的解决方案。我所做的最大缺陷是，当标题文本大小变化很大时，背景图像会拉伸(stretch)，导致圆角看起来有点偏离。

CustomBarButtonItem.h

#import <UIKit/UIKit.h>


@interface CustomBarButtonItem : UIBarButtonItem {}

- (id) initWithImage:(UIImage *)image title:(NSString *)title target:(id)target action:(SEL)action;

@end


@interface UIBarButtonItem (CustomBarButtonItem)

+ (UIBarButtonItem *) barButtonItemWithImage:(UIImage *)image title:(NSString *)title target:(id)target action:(SEL)action;

@end

CustomBarButtonItem.m

#import "CustomBarButtonItem.h"


@implementation CustomBarButtonItem

- (id) initWithImage:(UIImage *)image title:(NSString *)title target:(id)target action:(SEL)action {

    UIButton *barButton = [UIButton buttonWithType:UIButtonTypeCustom];
    UIFont *font = [UIFont boldSystemFontOfSize:13];
    barButton.titleLabel.font = font;
    barButton.titleLabel.shadowOffset = CGSizeMake(0, -1);
    barButton.titleEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 5);
    [barButton setImage:image forState:UIControlStateNormal];
    [barButton setTitle:title forState:UIControlStateNormal];
    [barButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [barButton setTitleColor:[UIColor lightGrayColor] forState:UIControlStateHighlighted];
    [barButton setTitleShadowColor:[[UIColor blackColor] colorWithAlphaComponent:0.5] forState:UIControlStateNormal];
    [barButton setBackgroundImage:[UIImage imageNamed:@"bar-button-item-background.png"] forState:UIControlStateNormal];
    barButton.frame = CGRectMake(0, 0, image.size.width + 15 + [title sizeWithFont:font].width, 30);

    if (self = [super initWithCustomView:barButton]) {
        self.target = target;
        self.action = action;
    }

    return self;
}

@end


@implementation UIBarButtonItem (CustomBarButtonItem)

+ (UIBarButtonItem *) barButtonItemWithImage:(UIImage *)image title:(NSString *)title target:(id)target action:(SEL)action {
    return [[[CustomBarButtonItem alloc] initWithImage:image title:title target:target action:action] autorelease];
}

@end

使用示例:

UIBarButtonItem *customButtonItem = [UIBarButtonItem barButtonItemWithImage:[UIImage imageNamed:@"calendar.png"] title:@"Add to calendar" target:self action:@selector(addToCalendar)];

我的按钮背景图片是: