35.标签栏(UITabBarController)

1.标签栏的基本概念

1. tabBar是UITabBar对象, UITabBarItem, 每一个tabBarItem对应一个viewController, tabBar高度为49,导航栏和状态栏高度为64.
2. 当tabBarItem超过5个时,系统会自动增加一个更多按钮, 点击更多按钮, 没有在底部出现的那些按钮会以列表的形式显示出来.
3. tabBar属性: tintColor(item被点击之后的颜色), barTintColor(背景颜色)图像设置.
4. tabBarItem可以设置titile, image, badgeValue. 可以使用系统样式创建tabBarItem.
5. UITabBarController是项目中常见的布局方式, 与 UINavigationController不同, 它的viewControllers都是并列的; 而 UINavigationController则是层次性的.
6. UITabBarController, UINavigationController, UITableViewController通常都是组合出现, 这种布局方式特别常见,一定掌握. UITabBarController和UINavigationController可以互相嵌套用.
7. UITabBarController的常用属性: viewControllers(显示的视图控制器), tabBar(标签栏), selectedIndex(选中某个tabBarItem).
8. AppDelegate –> window -> tabBar ->navigation ->view

2.基本运用

AppDelegate.m文件

#import "AppDelegate.h"#import "FirstViewController.h"#import "SecondViewController.h"#import "ThirdViewController.h"#import "FouthViewController.h"#import "FiveViewController.h"#import "SixViewController.h"//定义一个常量#define SELECTEDKEY @"selected"@interface AppDelegate ()<UITabBarControllerDelegate>@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    // Override point for customization after application launch.    self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    [_window release];    //AppDelegate --> window -> tabBar ->navigation ->view    //创建第一个视图控制器对象和第一个naVC    FirstViewController *firstVC = [[FirstViewController alloc] init];    UINavigationController *firstNav = [[UINavigationController alloc] initWithRootViewController:firstVC];    //创建tabbar上面的按钮及其内容    firstVC.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemHistory tag:1000] autorelease];![这里写图片描述](http://img.blog.csdn.net/20150812132815627)    SecondViewController *secondVC = [[SecondViewController alloc] init];    UINavigationController *secondNav = [[UINavigationController alloc ] initWithRootViewController:secondVC];    secondVC.tabBarItem = [[[UITabBarItem alloc] initWithTitle:@"动态" image:[UIImage imageNamed:@"iconfont-favor"] selectedImage:[UIImage imageNamed:@"iconfont-favorfill"]] autorelease];    ThirdViewController *thirdVC = [[ThirdViewController alloc] init];    UINavigationController *thirdNav = [[UINavigationController alloc] initWithRootViewController:thirdVC];    thirdVC.tabBarItem = [[[UITabBarItem alloc] initWithTitle:@"消息" image:[UIImage imageNamed:@"iconfont-message"] tag:1001] autorelease];    thirdVC.tabBarItem.badgeValue = @"+5";    FouthViewController *fouthVC = [[FouthViewController alloc] init];    UINavigationController *fouthNav = [[UINavigationController alloc] initWithRootViewController:fouthVC];    fouthVC.tabBarItem = [[[UITabBarItem alloc] initWithTitle:@"淘宝" image:[UIImage imageNamed:@"iconfont-mobiletao"] tag:1002] autorelease];    FiveViewController *fiveVC = [[FiveViewController alloc] init];    UINavigationController *fiveNav = [[UINavigationController alloc] initWithRootViewController:fiveVC];    fiveVC.tabBarItem = [[[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemRecents tag:1003] autorelease];    SixViewController *sixVC = [[SixViewController alloc] init];    UINavigationController *sixNav = [[UINavigationController alloc] initWithRootViewController:sixVC];    sixVC.tabBarItem = [[[UITabBarItem alloc] initWithTitle:@"刷新" image:[UIImage imageNamed:@"iconfont-refresh"] tag:1004] autorelease];#pragma mark 按钮创建好后创建tabBarController,通过一个数组来管理所要显示的Nav    UITabBarController *tabBar = [[[UITabBarController alloc] init] autorelease];    tabBar.viewControllers = @[firstNav,secondNav,thirdNav,fouthNav,fiveNav,sixNav];    self.window.rootViewController = tabBar;    //对tabbar进行外观设置    tabBar.tabBar.translucent = NO;    //背景颜色    tabBar.tabBar.barTintColor = [UIColor cyanColor];    //点击之后图标的颜色    tabBar.tabBar.tintColor = [UIColor redColor];    //设置代理人    tabBar.delegate = self;    //tabBar.selectedIndex = 2;    //让下次打开是显示在上次关闭的那一tabBarItem上面    NSString *viewControllerTitle = [[NSUserDefaults standardUserDefaults] objectForKey:SELECTEDKEY];    if (viewControllerTitle) {        for (UIViewController *vc in tabBar.viewControllers) {            if ([vc.tabBarItem.title isEqualToString:viewControllerTitle]) {                tabBar.selectedViewController = vc ;            }        }    }    [firstVC release];[firstNav release];[secondVC release];[secondNav release];[thirdNav release];[thirdVC release]; [fouthVC release];[fouthNav release];[fiveNav release];[fiveVC release];[sixVC release];[sixNav release];    return YES;}- (void)dealloc{    [_window release];    [super dealloc];}- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{    //把上面的badgeValue(标记值)去除, 如果= @"",那么显示出来的是一个小实心圆点.    viewController.tabBarItem.badgeValue = nil;    //通过方法得到NSUserDefaults,他是指向应用程序plist文件    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];    //如果可以拿到视图控制器的标题,调用setObject方法,将标题记录在NSUserDefaults,key定义一个常量,取值时候要与设定的值保持一致    if (viewController.tabBarItem.title) {        [defaults setObject:viewController.tabBarItem.title forKey:SELECTEDKEY];    }    //将数据同步给应用程序    [defaults synchronize];    //下一次进入程序,如果在NSUserDefaults能取到viewController.title,则会直接将标题栏控制器直接指向视图控制器,直接是视图控制器所对应的tabbar处于被选中的状态}

FirstViewController.m文件, 在里面添加一个tableView, 在cell上添加手势(又添加快捷菜单)和按钮, 在cell的判断里面写实现cell的重用

#import "FirstViewController.h"@interface FirstViewController ()<UITableViewDataSource,UITableViewDelegate>@property(nonatomic,retain)NSMutableArray *arr;@end@implementation FirstViewController- (instancetype)init{    self = [super init];    if (self) {        self.arr =  [NSMutableArray arrayWithObjects:@"宋江", @"卢俊义", @"吴用", @"公孙胜", @"关胜", @"林冲", @"秦明" ,@"呼延灼" , @"花容",@"柴进", @"李应", @"朱仝",@"鲁智深",@"武松",nil];    }    return self;}- (void)viewDidLoad {    [super viewDidLoad];    self.navigationController.navigationBar.translucent = NO;    UITableView *tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 375, 603-49) style:UITableViewStylePlain];   tableView.delegate = self;   tableView.dataSource = self;   [self.view addSubview:tableView];   [tableView release];}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    return self.arr.count;}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    static NSString *ID = @"mycell";    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];    if (cell == nil) {        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];        //在这里给cell添加手势,也实现了重用        UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(click:)];        [cell addGestureRecognizer:longPress];        [longPress release];        //也可以在这里添加视图按钮        UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];        button.frame = CGRectMake(300, 0, 100, 40);        [button setTitle:@"测试" forState:UIControlStateNormal];        [cell addSubview:button];    }    cell.textLabel.text = self.arr[indexPath.row];    return cell;}- (void)click:(UILongPressGestureRecognizer *)longPress{    //通过手势找到所添加的cell    UITableViewCell *cell = (UITableViewCell *)longPress.view;    //创建一个快捷菜单,单例    UIMenuController *menu = [UIMenuController sharedMenuController];    //给这个快捷菜单进行定位    [menu setTargetRect:cell.frame inView:cell.superview];    //让菜单显示出来    [menu setMenuVisible:YES animated:YES];    //如果想使用自定义的功能    UIMenuItem *flag = [[UIMenuItem alloc] initWithTitle:@"测试" action:@selector(flag)];    //把这个按钮放到快捷菜单上    [menu setMenuItems:@[flag]];    //不管是系统的还是自定义的方法必须要实现,否则不会添加到快捷菜单上}#pragma mark 快捷菜单捆绑了一个方法,这个方法必须实现,否则没法显示- (BOOL)canBecomeFirstResponder{    return YES;}- (void)delete:(id)sender{    NSLog(@"删除");}- (void)copy:(id)sender{    NSLog(@"复制");}- (void)select:(id)sender{    NSLog(@"选择");}- (void)flag{    NSLog(@"flag");}

3.简单截图