#import <UIKit/UIKit.h>@interface BSJTabBarViewController : UITabBarController@end#import "BSJTabBarViewController.h"#import "BSJTabBar.h"@interface BSJTabBarViewController ()@end@implementation BSJTabBarViewController#pragma mark --- life cycle- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.//    self.tabBarItem = [UITabBarItem application]    UITabBarItem *tabBarItem = [UITabBarItem  appearance];    //未选中的    NSMutableDictionary *norAttri = [NSMutableDictionary dictionary];    norAttri[NSFontAttributeName] = [UIFont systemFontOfSize:14];    norAttri[NSForegroundColorAttributeName] = [UIColor grayColor];    [tabBarItem setTitleTextAttributes:norAttri forState:UIControlStateNormal];    //选中的    NSMutableDictionary *selectAttri = [NSMutableDictionary dictionary];    selectAttri[NSForegroundColorAttributeName] = [UIColor darkGrayColor];    [tabBarItem setTitleTextAttributes:norAttri forState:UIControlStateSelected];        //精华    [self setupChridViewController:[[UITableViewController alloc] init] title:NSLocalizedString(@"精华", nil) normalImage:@"tabBar_essence_icon" selectedImage:@"tabBar_essence_click_icon"];    [self setupChridViewController:[[UIViewController alloc] init] title:NSLocalizedString(@"关注", nil) normalImage:@"tabBar_friendTrends_icon" selectedImage:@"tabBar_friendTrends_click_icon"];    [self setupChridViewController:[[UITableViewController alloc] init] title:NSLocalizedString(@"新帖", nil) normalImage:@"tabBar_new_icon" selectedImage:@"tabBar_new_click_icon"];    [self setupChridViewController:[[UITableViewController alloc] init] title:NSLocalizedString(@"我", nil) normalImage:@"tabBar_me_icon" selectedImage:@"tabBar_me_click_icon"];    // 通过KVC，可以改变属性为readOnly,改变它的Key，也就是通过它的value找到它的key    [self setValue:[[BSJTabBar alloc] init] forKey:@"tabBar"];    }- (void)setupChridViewController:(UIViewController *)vc title:(NSString *)title normalImage:(NSString *)normalImage   selectedImage:(NSString *)selectedImage{    vc.title      =  title;    if (normalImage.length && selectedImage.length ) {        vc.tabBarItem.image = [UIImage imageNamed:normalImage];        vc.tabBarItem.selectedImage = [UIImage imageNamed:selectedImage];    }      [self addChildViewController:vc];}//tabBar #import <UIKit/UIKit.h>@interface BSJTabBar : UITabBar@end#import "BSJTabBar.h"@interface BSJTabBar()@property (nonatomic, weak)UIButton      *publicButton;@end@implementation BSJTabBar- (void)layoutSubviews{    [super layoutSubviews];//    BSJLogFunc    CGFloat buttonW = self.frame.size.width/5;    CGFloat buttonH = self.frame.size.height;    CGFloat buttonY = 0;    CGFloat i = 0;    for (UIView *subView in self.subviews) {        BSJLog(@"%@",NSStringFromClass(subView.class));//        if (![subView.class isSubclassOfClass:[NSClassFromString(@"UITabBarButton") class]]) continue;        if (![@"UITabBarButton" isEqualToString:NSStringFromClass(subView.class)]) continue;        CGFloat buttonX = i*buttonW;        if (i >= 2) {            buttonX += buttonW;        }        subView.frame = CGRectMake(buttonX, buttonY, buttonW, buttonH);                i++;   }

//        [

self.publicButton setFrame:CGRectMake(0, 0, self.frame.size.width/5, self.frame.size.height)]; 
//

self.publicButton.center = CGPointMake(self.center.x, self.center.y);

}
 #pragma mark --- response methods
 - (void)buttonClick:(UIButton *)sender{ 
} 

#pragma mark --- setters and getters 
- (UIButton *)publicButton{
 if (!_publicButton) 
{ UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; 
[button setImage:[UIImage imageNamed:@"tabBar_publish_icon"] forState:UIControlStateNormal]; 
[button setImage:[UIImage imageNamed:@"tabBar_publish_click_icon"] forState:UIControlStateHighlighted];
 [button addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside]; 
 [self addSubview:button]; _publicButton = button; } return _publicButton; 
}
 @end