设置导航栏标题的文字属性

效果：

源码：

UINavigationController+TitleTextAttributes.h 与 UINavigationController+TitleTextAttributes.m

//
//  UINavigationController+TitleTextAttributes.h
//  NC
//
//  Copyright (c) 2014年 Y.X. All rights reserved.
//

#import <UIKit/UIKit.h>
@class NCTitleAttribute;

@interface UIViewController (TitleTextAttributes)

- (void)titleTextAttributes:(NCTitleAttribute *)attribute;

@end

//
//  UINavigationController+TitleTextAttributes.m
//  NC
//
//  Copyright (c) 2014年 Y.X. All rights reserved.
//

#import "UINavigationController+TitleTextAttributes.h"
#import "NCTitleAttribute.h"

@implementation UIViewController (TitleTextAttributes)

#pragma mark - public
- (void)titleTextAttributes:(NCTitleAttribute *)attribute
{
    [self controller:self
 titleTextAttributes:[attribute transformToDictionary]];
}

#pragma mark - private
- (void)controller:(UIViewController *)controller titleTextAttributes:(NSDictionary *)dictionary
{
    if ([controller isKindOfClass:[UIViewController class]])
    {
        [controller.navigationController.navigationBar setTitleTextAttributes:dictionary];
    }
}

@end

NCTitleAttribute.h 与 NCTitleAttribute.m

//
//  NCTitleAttribute.h
//  NC
//
//  Copyright (c) 2014年 Y.X. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NCTitleAttribute : NSObject

@property (nonatomic, strong) UIColor *titleColor;   // 标题颜色
@property (nonatomic, strong) UIFont  *titleFont;    // 标题字体

@property (nonatomic, strong) UIColor *shadowColor;  // 阴影颜色
@property (nonatomic, assign) CGSize   shadowOffset; // 阴影偏移量

// 将参数转换为字典
- (NSDictionary *)transformToDictionary;

@end

//
//  NCTitleAttribute.m
//  NC
//
//  Copyright (c) 2014年 Y.X. All rights reserved.
//

#import "NCTitleAttribute.h"

@implementation NCTitleAttribute

- (NSDictionary *)transformToDictionary
{
    NSMutableDictionary *dic = [NSMutableDictionary new];

    if (_titleColor)
    {
        [dic setObject:_titleColor forKey:NSForegroundColorAttributeName];
    }
    else
    {
        [dic setObject:[UIColor blackColor] forKey:NSForegroundColorAttributeName];
    }

    if (_titleFont)
    {
        [dic setObject:_titleFont forKey:NSFontAttributeName];
    }

    if (_shadowOffset.height || _shadowOffset.width)
    {
        NSShadow *shadow = [NSShadow new];

        shadow.shadowColor  = _shadowColor;
        shadow.shadowOffset = _shadowOffset;

        [dic setObject:shadow forKey:NSShadowAttributeName];
    }

    return dic;
}

@end

使用的源码：

//
//  RootViewController.m
//  NC
//
//  Copyright (c) 2014年 Y.X. All rights reserved.
//

#import "RootViewController.h"
#import "UINavigationController+TitleTextAttributes.h"
#import "NCTitleAttribute.h"
#import "FontPool.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor blackColor];

    [FontPool registerFont:bundleFont(@"华康少女字体.ttf")
                  withName:@"华康少女字体"];

    // 设置导航栏标题
    self.title = @"YouXianMing";
    NCTitleAttribute *titleAttribute = [NCTitleAttribute new];
    titleAttribute.titleColor        = [UIColor redColor];
    titleAttribute.titleFont         = [UIFont fontWithName:CUSTOM_FONT(@"华康少女字体", 0) size:20.f];
    titleAttribute.shadowColor       = [UIColor blackColor];
    titleAttribute.shadowOffset      = CGSizeMake(1, 1);

    [self titleTextAttributes:titleAttribute];
}

@end

简单的分析：

其实，核心的方法就一个而已

然后，将那个字典抽象成了对象，将复杂的设置转换成了简单的对象来理解

然后，使用的时候是通过category来实现

一个这么简单的功能为何要这么折腾？其实这就是提高效率的方案，将重复代码抽象成类，你不用再去关注复制粘贴代码，还不懂细节的含义，而是你可以见名知意一目了然而已。