使用UIAppearance分别自定义UIBarButtonItem"Done"样式和"Plain"样式

Question

我知道如何自定义UIBarButtonItem使用-setBackgroundImage: forState: barMetrics:,但我想使用不同的图像UIBarButtonItemStyleDone和UIBarButtonItemStylePlain.

有没有办法使用UIAppearance协议来实现这一目标？或者每次我想要一个"完成"样式按钮时我是否必须设置图像？

(我试着搞乱如下代码:

[[UIBarButtonItem appearance] setBackgroundImage:image forState:UIControlStateNormal barMetrics:UIBarButtonItemStyleDone];

但这只是用"完成"图像设置每个条形按钮.)

谢谢!

Answer 1

在iOS 6中,您可以使用UIBarButtonItem类的新方法:

- (void)setBackgroundImage:(UIImage *)backgroundImage
                  forState:(UIControlState)state
                     style:(UIBarButtonItemStyle)style
                barMetrics:(UIBarMetrics)barMetrics

它为指定的状态,样式和指标设置背景图像.Apple文档中提供了更多详细信息

因此,要更改所有UIBarButtonItem的外观,您可以使用以下内容:

UIImage *doneBackgroundImage = [[UIImage imageNamed:@"button_done.png"]
   resizableImageWithCapInsets:UIEdgeInsetsMake(0, 4, 0, 4)];

[[UIBarButtonItem appearance] setBackgroundImage:doneBackgroundImage
                                            forState:UIControlStateNormal
                                               style:UIBarButtonItemStyleDone
                                          barMetrics:UIBarMetricsDefault];

Answer 2

对于IOS5*

我找到的唯一方法是使用UIBarButtonItem类:

的UIBarButtonItem + Appearance.h

#import <Foundation/Foundation.h>

@interface UIBarButtonItem (Appearance)

+ (void) setupAppearance;

@end

的UIBarButtonItem + Appearance.m

#import "UIBarButtonItem+Appearance.h"
#import <objc/runtime.h>

@implementation UIBarButtonItem (Appearance)

+ (void) setupAppearance {
    [[UIBarButtonItem appearance]  setBackgroundImage: [[UIImage imageNamed:@"customButton"]
                                                                  resizableImageWithCapInsets: UIEdgeInsetsMake(8, 8, 8, 8)]
                                                       forState: UIControlStateNormal
                                                     barMetrics: UIBarMetricsDefault];

    [[UIBarButtonItem appearance]  setBackgroundImage: [[UIImage imageNamed:@"customButtonHiglhighted"]
                                                                  resizableImageWithCapInsets: UIEdgeInsetsMake(8, 8, 8, 8)]
                                                       forState: UIControlStateHighlighted
                                                     barMetrics: UIBarMetricsDefault];



    Class klass = objc_getClass("UIBarButtonItem");
    Method targetMethod = class_getInstanceMethod(klass, @selector(setStyle:));
    Method newMethod = class_getInstanceMethod(klass, @selector(__setStyle:));
    method_exchangeImplementations(targetMethod, newMethod);
}

- (void) __setStyle:(UIBarButtonItemStyle)style {
    [self __setStyle:style];

    if(style == UIBarButtonItemStyleDone) {
        [self setBackgroundImage:[[UIImage imageNamed:@"customDoneButton"] resizableImageWithCapInsets: UIEdgeInsetsMake(8, 8, 8, 8)]
                        forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
        [self setBackgroundImage:[UIImage imageNamed:@"customDoneButtonClicked"]
                        forState:UIControlStateHighlighted barMetrics:UIBarMetricsDefault];
    } else {
        [self setBackgroundImage:[[UIImage imageNamed:@"customButton"] resizableImageWithCapInsets: UIEdgeInsetsMake(8, 8, 8, 8)]
                        forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
        [self setBackgroundImage:[UIImage imageNamed:@"customButtonHighlighted"]
                        forState:UIControlStateHighlighted barMetrics:UIBarMetricsDefault];
    }
}

@end

希望这是你正在寻找的.这个解决方案的功劳归功于https://gist.github.com/2633081