ios 学习笔记，tabbarcontroller 实现底部导航

要求：通过tabbarcontroller实现一个底部导航，并且实现两个界面之间通过button切换，互相传值

参考博客
转

tabbar部分

AppDelegate.m

#import "AppDelegate.h"#import "ViewControl1.h"#import "ViewController2.h"#import "ViewController3.h"#import "ViewController4.h"@interface AppDelegate ()@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.    //创建windows    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];    self.window.backgroundColor = [UIColor whiteColor];    //初始化一个tabbarcontroller    UITabBarController *  bottomTabbarController = [[UITabBarController alloc ]init];    self.window.rootViewController = bottomTabbarController ;    //创建4个子控制器    ViewControl1 * view1 = [[ViewControl1 alloc]init];    view1.tabBarItem.title = @"view1";     ViewController2* view2 = [[ViewController2 alloc]init];    view2.tabBarItem.title = @"view2";    ViewController3 * view3 = [[ViewController3 alloc]init];    view3.tabBarItem.title = @"view3";    ViewController4 * view4 = [[ViewController4 alloc]init];    view4.tabBarItem.title = @"view4";    //添加子类控制器    bottomTabbarController.viewControllers = @[view1,view2,view3,view4];    //显示windows为主窗口    [self.window makeKeyAndVisible] ;    return YES;}- (void)applicationWillResignActive:(UIApplication *)application {}- (void)applicationDidEnterBackground:(UIApplication *)application {}- (void)applicationWillEnterForeground:(UIApplication *)application {}- (void)applicationDidBecomeActive:(UIApplication *)application {}- (void)applicationWillTerminate:(UIApplication *)application {}@end

1.在viewcontroller中用self.tabbarcontroller 取得tabbarcontrolle。
2. 给item添加image，view.tabbarItem.imgge.点击是的图片 view.tabbarItem.selectimgge

每一个viewcontroller

#import "ViewController3.h"@interface ViewController3 ()@end@implementation ViewController3- (void)viewDidLoad {    [super viewDidLoad];     _labelOFView3 = [[UILabel alloc]initWithFrame:CGRectMake(50, 50, 100, 30)];    _labelOFView3.text = @"this is view3";    [self.view addSubview:_labelOFView3];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

实现界面切换和传值

正向传值用的是属性传值，反向传值用的是block传值

viewcontroller1

#import <UIKit/UIKit.h>#import "ViewController2.h"@interface ViewControl1 : UIViewController@property(nonatomic ,strong )UILabel* labelOFView1;@end#import "ViewController2.h"#import "ViewControl1.h"@interface ViewControl1 ()@property(nonatomic ,strong)UITextField * toScondTextField;@property(nonatomic,strong )UIButton * sendButton  ;@end@implementation ViewControl1- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    _labelOFView1 = [[UILabel alloc]initWithFrame:CGRectMake(50, 50, 100, 30)];    _labelOFView1.text = @"this is view1";    [self.view addSubview:_labelOFView1];    self.toScondTextField;    [self.sendButton addTarget:self action:@selector(onclick:) forControlEvents:UIControlEventTouchUpInside];}-(void)onclick:(id)sender{    NSLog(@"click view1");    ViewController2 * vc2 = [self.tabBarController.viewControllers objectAtIndex:1];    vc2.str = _toScondTextField.text;    [vc2 returnText:^(NSString *text) {        self.labelOFView1.text =text;    }];//    [self presentViewController:vc2 animated:YES completion:nil];    [self.tabBarController setSelectedIndex:1];}-(UIButton *) sendButton{    if (!_sendButton) {        _sendButton = [[UIButton alloc]initWithFrame:CGRectMake(50, 150, 200,30)];        [_sendButton setTitle:@"to second View" forState:UIControlStateNormal];        [_sendButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];        _sendButton.backgroundColor = [UIColor grayColor];        [self.view addSubview:_sendButton];    }    return _sendButton  ;}-(UITextField *)toScondTextField{    if (!_toScondTextField) {        _toScondTextField = [[UITextField alloc] initWithFrame:CGRectMake(50, 200, 100, 30) ];        _toScondTextField.placeholder = @"input here";        [self.view addSubview:_toScondTextField];    }    return  _toScondTextField   ;}-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{    [self.view endEditing:YES];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

viewcontroller2

#import <UIKit/UIKit.h>typedef void (^returnStringBlock)(NSString * text);@interface ViewController2 : UIViewController@property(nonatomic ,strong )UILabel* labelOFView2;@property(nonatomic,strong) UITextField * toFirstViewTextView;@property(nonatomic,strong)UIButton * okButton;@property(nonatomic,copy) returnStringBlock textBlock;@property(nonatomic,copy)NSString* str;-(void) returnText : (returnStringBlock) block;@end#import "ViewController2.h"@interface ViewController2 ()@end@implementation ViewController2- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view.    _labelOFView2 = [[UILabel alloc]initWithFrame:CGRectMake(50, 50, 200, 30)];    if (_str) {        _labelOFView2.text = [NSString stringWithFormat:@"this is view2 %@",_str];    }else{        _labelOFView2.text = @"this is view2";    }    [self.view addSubview:_labelOFView2];    self.toFirstViewTextView    ;    [self.okButton addTarget:self action:@selector(onclick:) forControlEvents:UIControlEventTouchUpInside];}-(void)returnText:(returnStringBlock)block{    self.textBlock = block  ;}-(void)onclick:(id)sender{//    [self dismissViewControllerAnimated:YES completion:nil];    if (self.textBlock) {        self.textBlock(_toFirstViewTextView.text);    }    [self.tabBarController setSelectedIndex:0];}-(void)viewDidDisappear:(BOOL)animated{}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{    [self.view endEditing:YES];}//懒加载-(UIButton*) okButton{    if (!_okButton) {        _okButton = [[UIButton alloc]initWithFrame:CGRectMake(100, 150, 60, 35)];        [_okButton setTitle:@"ok" forState:UIControlStateNormal];        [_okButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];        _okButton.backgroundColor = [UIColor grayColor];        [self.view addSubview:_okButton];    }    return _okButton;}-(UITextField*)toFirstViewTextView{    if (!_toFirstViewTextView) {        _toFirstViewTextView = [[UITextField alloc]initWithFrame:CGRectMake(50, 200, 200, 30)];        _toFirstViewTextView.placeholder = @ "send to firsr view text";        [self.view addSubview:_toFirstViewTextView];    }    return _toFirstViewTextView;}@end

1.注意在控制器中取得切换 item的方法
[self.tabbarcontroller setselectIndex:];
2.在控制器中取得子视图
[self.tabbarcontroller.viewcontrollers objectIndex:];