创建UIBarButtonItem的分类

#import "UINavigationBar+Add.h"

#import "NSObject+Add.h"

 

static const int UI_BAR_BUTTON_ITEM_BLOCK_KEY;

 

@interface UIBarButtonItemBlockTarget : NSObject

@property (nonatomic, copy) UIBarButtonItemActionBlock block;

 

- (id)initWithBlock:(UIBarButtonItemActionBlock) block;

- (void)invoke:(id)sender;

 

@end

 

@implementation UIBarButtonItemBlockTarget

 

- (id)initWithBlock:(UIBarButtonItemActionBlock)block// 创建一个Block

{

    self = [super init];

    if (self)

    {

        _block = [block copy];

    }

    return self;

}

 

- (void)invoke:(id)sender

{

    !self.block?:self.block(sender);

}

 

@end

 

@implementation UIBarButtonItem (Add)

 

- (void)setActionBlock:(UIBarButtonItemActionBlock)block

{

    if (!block) return;

    

    UIBarButtonItemBlockTarget *target = [[UIBarButtonItemBlockTarget alloc] initWithBlock:block];

    

    // 系统类不允许添加实例变量、使用Runtime来关联

    [self setAssociateValue:target withKey:&UI_BAR_BUTTON_ITEM_BLOCK_KEY];

    [self setTarget:target];

    [self setAction:@selector(invoke:)];

}

 

- (UIBarButtonItemActionBlock)actionBlock

{

    // 系统类不允许添加实例变量、使用Runtime来关联

    UIBarButtonItemBlockTarget *target = [self getAssociatedValueForKey:&UI_BAR_BUTTON_ITEM_BLOCK_KEY];

    return target.block;

}

 

 

+ (UIBarButtonItem *)barButtonItemWithTarget:(id)target

                                      Action:(SEL)action

                                       image:(NSString *)image

                            HighlightedImage:(NSString *)highlightedImage

{

    UIButton *button = [[UIButton alloc] init];

    

    [button setImage:[UIImage imageNamed:image] forState:UIControlStateNormal];

    [button setImage:[UIImage imageNamed:highlightedImage] forState:UIControlStateHighlighted];

    [button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];

    button.size = button.currentImage.size; // 避免图片拉伸

    

    return [[UIBarButtonItem alloc] initWithCustomView:button];

}

 

/**

 *  @param image            默认图片

 *  @param highlightedImage 高亮状态图片

 *  @param actionBlock      回调block

 *

 *  @return barButtonItem

 */

+ (UIBarButtonItem *)barButtonItemWithImage:(NSString *)image highlightedImage:(NSString *)highlightedImage actionBlock:(UIBarButtonItemActionBlock)actionBlock

{

    UIBarButtonItem *barButtonItem = [UIBarButtonItem barButtonItemWithTarget:nil

                                                                       Action:nil

                                                                        image:image

                                                             HighlightedImage:highlightedImage];

    

    if (actionBlock)

    {

        [barButtonItem setActionBlock:actionBlock];

    }

    

    return barButtonItem;

}

 

/**

 *  @param image            默认图片

 *  @param highlightedImage 高亮状态图片

 *  @param actionBlock      回调block

 *

 *  @return barButtonItem

 */

+ (UIBarButtonItem *)barButtonItemWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style actionBlock:(UIBarButtonItemActionBlock)actionBlock

{

    UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithTitle:title style:style target:nil action:nil];

    

    if (actionBlock)

    {

        [barButtonItem setActionBlock:actionBlock];

    }

    

    return barButtonItem;

}

 

@end

 

这样做虽然复杂点，但是代码聚合起来更加方便清晰，难点：系统类不允许添加实例变量

所以使用runtime来关联属性

这样写就像：如果afnetworking不是以块，而是以代理的方式来做，会很麻烦

使用方法：这样关联创建和点击事件

self.navigationItem.rightBarButtonItem = [UIBarButtonItem barButtonItemWithTitle:@"Scroll" style:UIBarButtonItemStyleDone actionBlock:^(id sender) {

        NSLog(@"123");

    }];