UIBarButtonItem

 1 增加导航栏按钮方式一
   UIBarButtonItem的分类中增加下面的方法
 2 +(UIBarButtonItem *)itemWithImageName:(NSString *)imageName highImageName:(NSString *)highImageName target:(id)target action:(SEL)action;
 3 {
 4     UIButton *button = [[UIButton alloc]init];
 5     //设置背景图片
 6     [button setBackgroundImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];
 7     [button setBackgroundImage:[UIImage imageNamed:highImageName] forState:UIControlStateHighlighted];
 8     //按钮大小设置
 9     button.size = button.currentBackgroundImage.size;
10     //添加监听事件
11     [button addTarget:target action:action forControlEvents:UIControlEventTouchUpInside];
12     return [[UIBarButtonItem alloc]initWithCustomView:button];
13 }
14 
15 self.navigationItem.leftBarButtonItem = [UIBarButtonItem itemWithImageName:@"imageName” highImageName:@“highImageName” target:self action:@selector(friendSearch)];
16 
17 self.navigationItem.rightBarButtonItem = [UIBarButtonItem itemWithImageName:@"imageName" highImageName:@"highImageName" target:self action:@selector(pop)];
18 
19 增加导航栏按钮方式二
20 第一种方法：直接在控制器中定义UIBarButtonItem的样式并添加按钮
21     UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
22     [button setTitle:@"写私信" forState:UIControlStateNormal];
23     [button setTitleColor:[UIColor orangeColor] forState:UIControlStateNormal];
24     [button setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
25     [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateDisabled];
26     button.titleLabel.font = [UIFont systemFontOfSize:15];
27     button.size = [button.currentTitle sizeWithFont:button.titleLabel.font];
28     
29     self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:button];
30 
31 第二种方法：在导航控制器中设置UIBarButtonItem的全局样式，在各个控制器中添加按钮
32 //1.在导航控制器中设置UIBarButtonItem的样式，全局有效
33 +(void)initialize //该方法只会调用一次
34 {
35     //通过appearance对象能修改整个项目中所有UIBarButtonItem的样式
36     UIBarButtonItem *appearance = [UIBarButtonItem appearance];
37 
38     //1.普通状态
39     NSMutableDictionary *textAttrs = [NSMutableDictionary dictionary];
40     textAttrs[UITextAttributeTextColor] = [UIColor orangeColor];
41     textAttrs[UITextAttributeFont] = [UIFont systemFontOfSize:15];
42     [appearance setTitleTextAttributes:textAttrs forState:UIControlStateNormal];
43     
44     //2.高亮状态
45     NSMutableDictionary *highAttrs = [NSMutableDictionary dictionary];
46     highAttrs[UITextAttributeTextColor] = [UIColor redColor];
47     highAttrs[UITextAttributeFont] = [UIFont systemFontOfSize:15];
48     [appearance setTitleTextAttributes:highAttrs forState:UIControlStateHighlighted];
49     
50     //3.不可点击状态
51     NSMutableDictionary *disAttrs = [NSMutableDictionary dictionary];
52     disAttrs[UITextAttributeTextColor] = [UIColor lightGrayColor];
53     disAttrs[UITextAttributeFont] = [UIFont systemFontOfSize:15];
54     [appearance setTitleTextAttributes:disAttrs forState:UIControlStateDisabled];
55     
56 }
57 //2.在控制器中添加导航栏按钮
58     self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"写私信" style:UIBarButtonItemStyleDone target:self action:@selector(composeMsg)];