自定义TabBar

要自定义UITabBarController，首先我们必须了解UITabBarController结构与其各个相关类的关系（TabBarController、TabBar、TabButton及ViewController）。其中，TabButton是一个双态的Button（选中和未选中），行为和CheckBox、RadioButton类似。TabBar是TabButton的容器，负责TabButton的排布和互斥，保证同时只有一个Button为选中态。TabBarController包含了TabBar，并管理这一个ViewController的栈，在TabBar上的按钮点击时对栈上的ViewController位置进行相应的调整，从而保持TabBar和ViewController栈之间的一致性。      熟悉了基本结构后，一般有以下常见的方案来完整自定义TabBarController。 方案一：替换部分现有的实现      目标是替换掉系统的部分控件，可通过隐藏TabBar的方式来实现。只要做到隐藏原有的TabBar后，不要忘了在新定制的TabBar的当前选中按钮变化时通过UITabBarController的setSelectedIndex接口设置ViewController栈的当前ViewController即可。 View Code 复制代码 1 #import<UIKit/UIKit.h>2 @interface CustomTabBar : UITabBarController { 3 NSMutableArray *buttons; 4 int currentSelectedIndex; 5 UIImageView *slideBg; 6 } 7 8 @property (nonatomic,assign) int currentSelectedIndex; 9 @property (nonatomic,retain) NSMutableArray *buttons; 10 11 - (void)hideRealTabBar; 12 - (void)customTabBar; 13 - (void)selectedTab:(UIButton *)button; 14 15 @end 复制代码 View Code 复制代码 1 #import "CustomTabBar.h" 2 3 @implementation CustomTabBar 4 5 @synthesize currentSelectedIndex; 6 @synthesize buttons; 7 8 - (void)viewDidAppear:(BOOL)animated{ 9 slideBg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bottomfocus.png"]]; 10 [self hideRealTabBar]; 11 [self customTabBar]; 12 } 13 14 - (void)hideRealTabBar{ 15 for(UIView *view in self.view.subviews){ 16 if([view isKindOfClass:[UITabBar class]]){ 17 view.hidden = YES; 18 break; 19 } 20 } 21 } 22 23 - (void)customTabBar{ 24 UIImageView *imgView = [[UIImageView alloc] initWithImage: [UIImage imageNamed:@"tabbg2.png"]]; 25 imgView.frame = CGRectMake(0, 425, imgView.image.size.width, imgView.image.size.height); 26 [self.view addSubview:imgView]; 27 slideBg.frame = CGRectMake(-30, self.tabBar.frame.origin.y, slideBg.image.size.width, slideBg.image.size.height); 28 29 //创建按钮 30 int viewCount = self.viewControllers.count > 5 ? 5 : self.viewControllers.count; 31 self.buttons = [NSMutableArray arrayWithCapacity:viewCount]; 32 double _width = 320 / viewCount; 33 double _height = self.tabBar.frame.size.height; 34 for (int i = 0; i < viewCount; i++) { 35 UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom]; 36 btn.frame = CGRectMake(i*_width,self.tabBar.frame.origin.y, _width, _height); 37 [btn addTarget:self action:@selector(selectedTab:) forControlEvents:UIControlEventTouchUpInside]; 38 btn.tag = i; 39 [self.buttons addObject:btn]; 40 [self.view addSubview:btn]; 41 [btn release]; 42 } 43 [self.view addSubview:slideBg]; 44 UIImageView *imgFront = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"tabitem.png"]]; 45 imgFront.frame = imgView.frame; 46 [self.view addSubview:imgFront]; 47 [imgFront release]; 48 [imgView release]; 49 [self selectedTab:[self.buttons objectAtIndex:0]]; 50 51 } 52 53 - (void)selectedTab:(UIButton *)button{ 54 if (self.currentSelectedIndex == button.tag) { 55 56 } 57 self.currentSelectedIndex = button.tag; 58 self.selectedIndex = self.currentSelectedIndex; 59 [self performSelector:@selector(slideTabBg:) withObject:button]; 60 } 61 62 - (void)slideTabBg:(UIButton *)btn{ 63 [UIView beginAnimations:nil context:nil]; 64 [UIView setAnimationDuration:0.20]; 65 [UIView setAnimationDelegate:self]; 66 slideBg.frame = CGRectMake(btn.frame.origin.x - 30, btn.frame.origin.y, slideBg.image.size.width, slideBg.image.size.height); 67 [UIView commitAnimations]; 68 } 69 70 - (void) dealloc{ 71 [slideBg release]; 72 [buttons release]; 73 [super dealloc]; 74 } 75 @end 复制代码 使用这个自定义类来创建UITabBarController View Code 复制代码 1 // Override point for customization after application launch. 2 FirstViewController *mainViewController = [[FirstViewController alloc] init]; 3 SecondViewController *searchViewController = [[SecondViewController alloc]init]; 4 ThirdViewController *myselfViewController = [[ThirdViewController alloc]init]; 5 ForthViewController *settingViewController = [[ForthViewController alloc]init]; 6 7 //隐藏tabbar所留下的黑边（试着注释后你会知道这个的作用） 8 mainViewController.hidesBottomBarWhenPushed = true; 9 searchViewController.hidesBottomBarWhenPushed = true; 10 myselfViewController.hidesBottomBarWhenPushed = true; 11 settingViewController.hidesBottomBarWhenPushed = true; 12 13 mainViewController.title = @"首页"; 14 searchViewController.title = @"搜索"; 15 myselfViewController.title = @"我"; 16 settingViewController.title = @"设置"; 17 18 //创建导航 19 UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:mainViewController ]; 20 UINavigationController *nav1 = [[ UINavigationController alloc] initWithRootViewController:searchViewController]; 21 UINavigationController *nav2 = [[UINavigationController alloc] initWithRootViewController:myselfViewController]; 22 UINavigationController *nav3 = [[UINavigationController alloc]initWithRootViewController:settingViewController]; 23 //创建数组 24 NSMutableArray *controllers = [[NSMutableArray alloc]init]; 25 [controllers addObject:nav]; 26 [controllers addObject:nav1]; 27 [controllers addObject:nav2]; 28 [controllers addObject:nav3]; 29 30 //创建tabbar 31 tabBarController = [[ CustomTabBar alloc] init]; 32 tabBarController.viewControllers = controllers; 33 tabBarController.selectedIndex = 0; 34 35 //显示 36 [self.window addSubview:tabBarController.view]; 37 [self.window makeKeyAndVisible];