iOS系統導航欄中有leftBarButtonItem和rightBarButtonItem，我們可以根據自己的需求來自定義這兩個UIBarButtonItem。

四種創建方法

系統提供了四種創建的方法：
復制代碼 代碼如下:
- (instancetype)initWithBarButtonSystemItem:(UIBarButtonSystemItem)systemItem target:(id)target action:(SEL)action;

- (instancetype)initWithImage:(UIImage *)image style:(UIBarButtonItemStyle)style target:(id)target action:(SEL)action;

- (instancetype)initWithTitle:(NSString *)title style:(UIBarButtonItemStyle)style target:(id)target action:(SEL)action;

- (instancetype)initWithBarButtonSystemItem:(UIBarButtonSystemItem)systemItem target:(id)target action:(SEL)action;

- (instancetype)initWithCustomView:(UIView *)customView;

通過系統UIBarButtonSystemItem創建

自定義rightBarButtonItem，代碼如下：
復制代碼 代碼如下:
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(right:)];

UIBarButtonSystemItem有以下樣式可以供選擇：
復制代碼 代碼如下:
typedef NS_ENUM(NSInteger, UIBarButtonSystemItem) {
    UIBarButtonSystemItemDone,
    UIBarButtonSystemItemCancel,
    UIBarButtonSystemItemEdit, 
    UIBarButtonSystemItemSave, 
    UIBarButtonSystemItemAdd,
    UIBarButtonSystemItemFlexibleSpace,
    UIBarButtonSystemItemFixedSpace,
    UIBarButtonSystemItemCompose,
    UIBarButtonSystemItemReply,
    UIBarButtonSystemItemAction,
    UIBarButtonSystemItemOrganize,
    UIBarButtonSystemItemBookmarks,
    UIBarButtonSystemItemSearch,
    UIBarButtonSystemItemRefresh,
    UIBarButtonSystemItemStop,
    UIBarButtonSystemItemCamera,
    UIBarButtonSystemItemTrash,
    UIBarButtonSystemItemPlay,
    UIBarButtonSystemItemPause,
    UIBarButtonSystemItemRewind,
    UIBarButtonSystemItemFastForward,
#if __IPHONE_3_0 <= __IPHONE_OS_VERSION_MAX_ALLOWED
    UIBarButtonSystemItemUndo,
    UIBarButtonSystemItemRedo,
#endif
#if __IPHONE_4_0 <= __IPHONE_OS_VERSION_MAX_ALLOWED
    UIBarButtonSystemItemPageCurl,
#endif
};

最後別忘了實現right:方法：
復制代碼 代碼如下:
- (void)right:(id)sender
{
    NSLog(@"rightBarButtonItem");
}

自定義文字的UIBarButtonItem

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"back" style:UIBarButtonItemStylePlain target:self action:@selector(back:)];
UIBarButtonItemStyle有以下三種選擇：
復制代碼 代碼如下:
typedef NS_ENUM(NSInteger, UIBarButtonItemStyle) {
    UIBarButtonItemStylePlain,
    UIBarButtonItemStyleBordered NS_ENUM_DEPRECATED_IOS(2_0, 8_0, "Use UIBarButtonItemStylePlain when minimum deployment target is iOS7 or later"),
    UIBarButtonItemStyleDone,
};

實現back:方法：
復制代碼 代碼如下:
- (void)back:(id)sender
{
    [self.navigationController popViewControllerAnimated:YES];
}

自定義照片的UIBarButtonItem
復制代碼 代碼如下:
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"test"] style:UIBarButtonItemStylePlain target:self action:@selector(right:)];

自定義UIView的UIBarButtonItem

自定義UIView，然後通過initWithCustomView:方法來創建UIBarButtonItem。
復制代碼 代碼如下:
UIView *testView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 40, 60)];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:testView];

看到有朋友在後台提問：

我現在即需要改那個導航原生的返回圖片，也要改返回文字，應該怎麼改呢，求指教。
其實，這個就可以用initWithCustomView:來解決，自定義UIView你可以放UIImageView和UILabel。可以自定義UIView，那麼想怎麼定義都是可以的。

下面來看一個有趣的例子：
先說一下需求：
1.做一個RightBarButtonItem不斷旋轉的Demo；
2.點擊RightBarButtonItem 按鈕旋轉或暫停；
最終效果展示：

就是那個音符圖形的旋轉。
關鍵代碼展示（已加注釋）：
復制代碼 代碼如下:
//
// ViewController.m
// NavigationBtn
//

#import "ViewController.h"
#define DEGREES_TO_RADIANS(angle) ((angle) / 180.0 * M_PI)

///ImageView旋轉狀態枚舉
typedef enum {
RotateStateStop,
RotateStateRunning,
}RotateState;

@interface ViewController ()
{
///旋轉角度
CGFloat imageviewAngle;
///旋轉ImageView
UIImageView *imageView;
///旋轉狀態
RotateState rotateState;
}

@end

復制代碼 代碼如下:
@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];
self.title=@"微信公眾賬號:樂Coding";
[self buildBarButtonItem];
}
#pragma mark 添加 RightBarButtonItem
-(void)buildBarButtonItem{

imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"icon"]];
imageView.autoresizingMask = UIViewAutoresizingNone;
imageView.contentMode = UIViewContentModeScaleToFill;
imageView.bounds=CGRectMake(0, 0, 40, 40);
//設置視圖為圓形
imageView.layer.masksToBounds=YES;
imageView.layer.cornerRadius=20.f;
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 40, 40);
[button addSubview:imageView];
[button addTarget:self action:@selector(animate) forControlEvents:UIControlEventTouchUpInside];
imageView.center = button.center;
//設置RightBarButtonItem
UIBarButtonItem *barItem = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.rightBarButtonItem = barItem;
}
#pragma mark 點擊 RightBarButtonItem
- (void)animate {
//改變ImageView旋轉狀態
if (rotateState==RotateStateStop) {
rotateState=RotateStateRunning;
[self rotateAnimate];
}else{
rotateState=RotateStateStop;
}
}
#pragma mark 旋轉動畫
-(void)rotateAnimate{
imageviewAngle+=50;
//0.5秒旋轉50度
[UIView animateWithDuration:0.5 delay:0.0 options:UIViewAnimationOptionCurveLinear animations:^{
imageView.transform = CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(imageviewAngle));
} completion:^(BOOL finished) {
if (rotateState==RotateStateRunning) {
[self rotateAnimate];
}
}];
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end