UI加强(三)之TabbarController, 键盘弹出的通知小结,modal控制器
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未完待续,先把代码上传到文件中去...
代理属性用weak修饰
block属性用copy修饰
为什么???
还有block的三种写法
1.typedef
2.@property (nonatomic,copy)dispatch_block_t listBlock;
3.直接写
还有:代理,通知,block这三种传递数据方法的总结:
1.UITabBarController和UINavigationController的常用属性总结:
UINavigationController属性:
1.self.title 和self.navigationItem.title以及self.tabBarItem.title的区别
只要设置self.title,那么self.navigationItem.title和self.tabBarItem.title值不管设置与否都和self.title一致
所以,一般情况下不要直接设置self.title,需要navigationItem.title就设置navigationItem.title,需要tabBarItem.title就设置tabBarItem.title
2.如上图:navigationItem可以设置:title,titleView,left/right barButtonItem,backBarButtonItem
navigationBar可以设置:tintColor,transluCent
注意:渲染颜色只能用:
vc1.navigationController.navigationBar.barTintColor = [UIColor redColor];
不能写成:
[vc1.navigationController.navigationBar setTintColor:[UIColor redColor]];
因为这种设置不上去
还要注意一点经常很容易犯的错误:见代码红色部分
// // AppDelegate.m // nav练习第二波 // // Created by 曹魏 on 2016/11/30. // Copyright © 2016年 itcast. All rights reserved. // #import "AppDelegate.h" #import "FirstTableViewController.h" @interface AppDelegate () @end @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { //1.实例化window self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds]; //2.设置window的背景颜色 self.window.backgroundColor = [UIColor whiteColor]; //3.实例化一个导航控制器 UINavigationController *nav = [[UINavigationController alloc]init]; //4.实例化一个tabbleView控制器 FirstTableViewController *first = [[FirstTableViewController alloc]init]; //5.设置tabbleView的背景颜色 first.tableView.backgroundColor = [UIColor blueColor];
//写在这儿是不显示的 // [tabbleVC.navigationController.navigationBar setTranslucent:NO]; //6.管理子控制器 nav.viewControllers = @[first]; //这两行代码的位置要注意,一定要写在第6步下面,如果写在上面是无法显示的,因为,我必须先管理这个控制器再设置navigationBar的一些属性 first.navigationController.navigationBar.barTintColor = [UIColor redColor]; [first.navigationController.navigationBar setTranslucent:NO]; //千万不要设置navigationController的对象nav上,因为是无效的 //7.设置window的根控制器 self.window.rootViewController = nav; //8.使window成为主窗口并可见 [self.window makeKeyAndVisible]; return YES; }
3.基本属性设置如下代码所示:
// // AppDelegate.m // UINavigationController小结 // // Created by 曹魏 on 2016/11/30. // Copyright © 2016年 itcast. All rights reserved. // #import "AppDelegate.h" @interface AppDelegate () @end @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { //1.实例化一个window self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds]; //2.设置window的背景颜色 self.window.backgroundColor = [UIColor whiteColor]; //3.实例化一个导航控制器 UINavigationController *nav = [[UINavigationController alloc]init]; //4.实例化一个控制器 UITableViewController *vc1 = [[UITableViewController alloc]init]; vc1.view.backgroundColor = [UIColor grayColor]; //4.1设置title vc1.navigationItem.title = @"隔壁老王"; // vc1.title = @"主界面"; // 4.2设置titleview(会覆盖title) UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 60, 35)]; imageView.image = [UIImage imageNamed:@"navigationbar_friendsearch"]; vc1.navigationItem.titleView = imageView; //4.3设置返回按钮 vc1.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"返回" style:UIBarButtonItemStylePlain target:nil action:nil]; //4.4添加导航栏左边的按钮 vc1.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:nil action:nil]; //4.5添加导航栏右边的按钮 vc1.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemSave target:nil action:nil]; // [vc1.navigationController.navigationBar setBarStyle:UIBarStyleBlack]; UITableViewController *vc2 = [[UITableViewController alloc]init]; vc2.view.backgroundColor = [UIColor purpleColor]; //设置title vc2.navigationItem.title = @"天龙八部"; //5.管理该控制器 nav.viewControllers = @[vc1,vc2]; //4.6设置渲染颜色 // [vc1.navigationController.navigationBar setTintColor:[UIColor redColor]]; vc1.navigationController.navigationBar.barTintColor = [UIColor redColor]; [vc1.navigationController.navigationBar setTranslucent:NO]; // [vc1.navigationController.navigationBar setBarStyle:UIBarStyleBlack]; //6.设置window的根控制器 self.window.rootViewController = nav; //7.使window成为主窗口并可见 [self.window makeKeyAndVisible]; return YES; } @end
UITabBarController的基本属性:
代码没有进行封装,但相对很完整,看效果图
// // AppDelegate.m // tabbarController的小练习 // // Created by 曹魏 on 2016/11/30. // Copyright © 2016年 itcast. All rights reserved. // #import "AppDelegate.h" @interface AppDelegate () @end @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { //1.实例化window self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds]; //2.设置window的背景颜色 self.window.backgroundColor = [UIColor whiteColor]; //3.实例化tabbar控制器 UITabBarController *tab = [[UITabBarController alloc]init]; //4.实例化taberviewController UITableViewController *first = [[UITableViewController alloc]init]; first.tableView.backgroundColor = [UIColor purpleColor]; //设置第一个控制器的属性 first.tabBarItem.title = @"微信"; //设置title文字颜色
//设置title文字颜色这个要注意,这个方法不好记
[first.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor colorWithRed:31/255.0 green:185/255.0 blue:34/255.0 alpha:1.0]} forState:UIControlStateSelected]; //设置图片 first.tabBarItem.image = [UIImage imageNamed:@"tabbar_mainframe"]; //设置选中状态下的图片 first.tabBarItem.selectedImage = [[UIImage imageNamed:@"tabbar_mainframeHL"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
//设置信息
first.tabBarItem.badgeValue = @"10";
UITableViewController *second = [[UITableViewController alloc]init]; second.tableView.backgroundColor = [UIColor redColor]; second.tabBarItem.title = @"通讯录"; //设置图片 second.tabBarItem.image = [UIImage imageNamed:@"tabbar_contacts"]; //设置选中状态下的图片 second.tabBarItem.selectedImage = [[UIImage imageNamed:@"tabbar_contactsHL"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]; //设置title文字颜色 [second.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor colorWithRed:31/255.0 green:185/255.0 blue:34/255.0 alpha:1.0]} forState:UIControlStateSelected]; UITableViewController *third = [[UITableViewController alloc]init]; third.tableView.backgroundColor = [UIColor grayColor]; third.tabBarItem.title = @"发现"; //设置图片 third.tabBarItem.image = [UIImage imageNamed:@"tabbar_discover"]; //设置选中状态下的图片 third.tabBarItem.selectedImage = [[UIImage imageNamed:@"tabbar_discoverHL"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]; //设置title文字颜色 [third.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor colorWithRed:31/255.0 green:185/255.0 blue:34/255.0 alpha:1.0]} forState:UIControlStateSelected]; UITableViewController *four = [[UITableViewController alloc]init]; four.tableView.backgroundColor = [UIColor yellowColor]; four.tabBarItem.title = @"我"; //设置title文字颜色 [four.tabBarItem setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor colorWithRed:31/255.0 green:185/255.0 blue:34/255.0 alpha:1.0]} forState:UIControlStateSelected]; //设置图片 four.tabBarItem.image = [UIImage imageNamed:@"tabbar_me"]; //设置选中状态下的图片 four.tabBarItem.selectedImage = [[UIImage imageNamed:@"tabbar_meHL"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]; //5.管理控制器 tab.viewControllers = @[first,second,third,four]; //6.设置window的根控制器 self.window.rootViewController = tab; //7.使window成为主窗口并可见 [self.window makeKeyAndVisible]; return YES; }@end
2.UITabBarController和UINavigationController的区别总结:
TabBarController 在进行界面切换, 没有看到的控制器, 没有被销毁
NavigationController控制器在pop操作后会被销毁
StoryBoard中跳转界面时二者的区别:
NavigationController跳转的时候选择的是用push
TabBarController跳转的时候选择的是view controllers(数组,有序)
3.键盘弹出的通知小结:
// // ViewController.m // 键盘响应小练习第二种 // // Created by 曹魏 on 2016/12/2. // Copyright © 2016年 itcast. All rights reserved. // #import "ViewController.h" @interface ViewController ()<UITextFieldDelegate> @property (weak, nonatomic) IBOutlet UITextField *nameField; @property (weak, nonatomic) IBOutlet UITextField *phoneField; @property (weak, nonatomic) IBOutlet UITextField *addressField; @property (nonatomic,assign) CGFloat maxY; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; //取消自动联想功能 _nameField.autocorrectionType = UITextAutocorrectionTypeNo; _phoneField.autocorrectionType = UITextAutocorrectionTypeNo; _addressField.autocorrectionType = UITextAutocorrectionTypeNo; //设置代理 _nameField.delegate = self; _phoneField.delegate = self; _addressField.delegate = self; //当我点击textfield的时候,系统会发出一些通知,我通过添加控制器为监听者来监听各种通知 //从而实现view的上移 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeKeyboard:) name:UIKeyboardWillChangeFrameNotification object:nil]; } - (void)changeKeyboard:(NSNotification *)notification{ NSLog(@"键盘事件 %@",notification); // {name = UIKeyboardWillShowNotification; userInfo = { // UIKeyboardAnimationCurveUserInfoKey = 7; 执行动画的方式,执行动画的样式 // UIKeyboardAnimationDurationUserInfoKey = "0.25"; 动画执行的时间 // UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {375, 258}}"; 键盘的bounds // UIKeyboardCenterBeginUserInfoKey = "NSPoint: {187.5, 796}"; 键盘开始(为显示)的中心点 // UIKeyboardCenterEndUserInfoKey = "NSPoint: {187.5, 538}"; 键盘结束(已经显示)的中心店 // UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 667}, {375, 258}}"; 键盘未显示时的frame // UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 409}, {375, 258}}"; 键盘结束时的frame // UIKeyboardIsLocalUserInfoKey = 1; 是否是当前弹出的键盘 // } NSDictionary *userInfo = notification.userInfo; //动画 CGFloat duration = [userInfo[@"UIKeyboardAnimationDurationUserInfoKey"] floatValue]; //获取键盘弹出后的frame CGFloat keyBoardY = [userInfo[@"UIKeyboardFrameEndUserInfoKey"] CGRectValue].origin.y; [UIView animateWithDuration:duration animations:^{ if (_maxY > keyBoardY) { CGFloat move = keyBoardY - _maxY - 10; self.view.transform = CGAffineTransformMakeTranslation(0, move); }else{ self.view.transform = CGAffineTransformIdentity; } }]; } #pragma mark -- 实现代理方法 - (void)textFieldDidBeginEditing:(UITextField *)textField{ //获取textfield的frame最大y值 _maxY = CGRectGetMaxY(textField.frame); } - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{ //取消第一响应者 [self.view endEditing:YES]; } @end
小结:1:当我点击textField的时候,如果是在storyBoard中添加控件并连线的方式的话,系统会自动在我点击的时候,让该textField成为第一响应者(效果也就是弹出键盘)
当我用纯代码写的时候,我点击textField是不会自动弹出键盘的,这个时候必须要加一句代码:[self.textField becomeFirstResponder];才可以.
2:当我点击textField的时候,系统会发出相应的通知,详细见下方,可根据相应的通知采取相应的办法去完成键盘的变化
UIKIT_EXTERN NSNotificationName const UIWindowDidBecomeVisibleNotification; // nil UIKIT_EXTERN NSNotificationName const UIWindowDidBecomeHiddenNotification; // nil UIKIT_EXTERN NSNotificationName const UIWindowDidBecomeKeyNotification; // nil UIKIT_EXTERN NSNotificationName const UIWindowDidResignKeyNotification; // nil // Each notification includes a nil object and a userInfo dictionary containing the // begining and ending keyboard frame in screen coordinates. Use the various UIView and // UIWindow convertRect facilities to get the frame in the desired coordinate system. // Animation key/value pairs are only available for the "will" family of notification. UIKIT_EXTERN NSNotificationName const UIKeyboardWillShowNotification __TVOS_PROHIBITED; UIKIT_EXTERN NSNotificationName const UIKeyboardDidShowNotification __TVOS_PROHIBITED; UIKIT_EXTERN NSNotificationName const UIKeyboardWillHideNotification __TVOS_PROHIBITED; UIKIT_EXTERN NSNotificationName const UIKeyboardDidHideNotification __TVOS_PROHIBITED; UIKIT_EXTERN NSString *const UIKeyboardFrameBeginUserInfoKey NS_AVAILABLE_IOS(3_2) __TVOS_PROHIBITED; // NSValue of CGRect UIKIT_EXTERN NSString *const UIKeyboardFrameEndUserInfoKey NS_AVAILABLE_IOS(3_2) __TVOS_PROHIBITED; // NSValue of CGRect UIKIT_EXTERN NSString *const UIKeyboardAnimationDurationUserInfoKey NS_AVAILABLE_IOS(3_0) __TVOS_PROHIBITED; // NSNumber of double UIKIT_EXTERN NSString *const UIKeyboardAnimationCurveUserInfoKey NS_AVAILABLE_IOS(3_0) __TVOS_PROHIBITED; // NSNumber of NSUInteger (UIViewAnimationCurve) UIKIT_EXTERN NSString *const UIKeyboardIsLocalUserInfoKey NS_AVAILABLE_IOS(9_0) __TVOS_PROHIBITED; // NSNumber of BOOL // Like the standard keyboard notifications above, these additional notifications include // a nil object and begin/end frames of the keyboard in screen coordinates in the userInfo dictionary. UIKIT_EXTERN NSNotificationName const UIKeyboardWillChangeFrameNotification NS_AVAILABLE_IOS(5_0) __TVOS_PROHIBITED; UIKIT_EXTERN NSNotificationName const UIKeyboardDidChangeFrameNotification NS_AVAILABLE_IOS(5_0) __TVOS_PROHIBITED;
上述只是第一种思路去让键盘弹出发出通知达到输入框上移的效果,这种思路比较有针对性,就是经过了一个判断:当键盘没有盖住输入框时,不上移,盖住了才上移,下面还有一种方法是无论盖不盖住都上移固定的距离,代码如下:
// // ViewController.m // 键盘响应小练习 // // Created by 曹魏 on 2016/12/1. // Copyright © 2016年 itcast. All rights reserved. // #import "ViewController.h" @interface ViewController () @property (weak, nonatomic) IBOutlet UITextField *birthdayField; @property (weak, nonatomic) IBOutlet UITextField *nameField; @property (weak, nonatomic) IBOutlet UITextField *addressField; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; //取消键盘的自动联想功能 self.birthdayField.autocorrectionType = UITextAutocorrectionTypeNo; self.nameField.autocorrectionType = UITextAutocorrectionTypeNo; self.addressField.autocorrectionType = UITextAutocorrectionTypeNo; //键盘将要显示 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeKeyboard:) name:UIKeyboardWillShowNotification object:nil]; //键盘将要隐藏 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeKeyboard:) name:UIKeyboardWillHideNotification object:nil]; } - (void)changeKeyboard:(NSNotification *)notification{ //获取额外信息 NSDictionary *userInfo = notification.userInfo; //获取结束时的frame CGRect endFrame = [userInfo[@"UIKeyboardFrameEndUserInfoKey"] CGRectValue]; //计算要移动的距离 CGFloat move = endFrame.origin.y - self.view.bounds.size.height; //让界面跟着移动 self.view.transform = CGAffineTransformMakeTranslation(0, move); } - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{ [self.view endEditing:YES]; } @end
说实话:这个方法的心机好重,很绕弯子!!!!
小知识点:
@property 和_实例变量的区别:
@property多了set 和get 方法的声明和实现
4.用户偏好设置的封装
采用分类的方式对NSUserDefaults进行封装,很简单的,就是在分类中提供一些接口,接口做成类方法,供NSUserDefaults使用,主要注意枚举的写法.
// // NSUserDefaults+WP.h // 01-通讯录 // // Created by apple on 16/8/1. // Copyright © 2016年 itcast. All rights reserved. // #import <Foundation/Foundation.h> /** 分类的主要目的: 帮我们保存和获取 存储的value */ // 定义 枚举, 来分辨 是那种开关 typedef NS_ENUM(NSInteger, SwitchType) { SwitchTypeRecord, SwitchTypeAuto }; @interface NSUserDefaults (WP) /** 返回值 传递的参数 key 值, 保存的值 */ // 保存 按钮状态 + (void)saveBoolValue:(BOOL)value forType:(SwitchType)type; // 获取按钮状态 + (BOOL)getBoolVlaueWithType:(SwitchType)type; @end
// // NSUserDefaults+WP.m // 01-通讯录 // // Created by apple on 16/8/1. // Copyright © 2016年 itcast. All rights reserved. // #import "NSUserDefaults+WP.h" #define kAutoSwitch @"autoSwitch" #define kRecordSwitch @"recordSwitch" @implementation NSUserDefaults (WP) // 保存 按钮状态 + (void)saveBoolValue:(BOOL)value forType:(SwitchType)type { // 根据type的类型, 来决定key值 NSString *key = type == SwitchTypeAuto ? kAutoSwitch : kRecordSwitch; [[NSUserDefaults standardUserDefaults] setBool:value forKey:key]; // 强制写入一次 [[NSUserDefaults standardUserDefaults] synchronize]; } // 获取按钮状态 + (BOOL)getBoolVlaueWithType:(SwitchType)type { // 根据type的类型, 来决定key值 NSString *key = type == SwitchTypeAuto ? kAutoSwitch : kRecordSwitch; return [[NSUserDefaults standardUserDefaults] boolForKey:key]; } + (void)resetAllValues { [[NSUserDefaults standardUserDefaults] setBool:NO forKey:kRecordSwitch]; [[NSUserDefaults standardUserDefaults] setBool:NO forKey:kAutoSwitch]; // [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:kUserName]; // [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:kPassword]; } @end
5.修改分割线缩进:
解释:就是将tableview的线距离屏幕左右为0 ,达到没有间距的效果.
所以,可以把这个当成万能代码直接拷贝!!!
/** 修改分割线缩进为0 */ - (void)viewDidLayoutSubviews { if ([self.tableView respondsToSelector:@selector(setSeparatorInset:)]) { [self.tableView setSeparatorInset:UIEdgeInsetsMake(0, 0, 0, 0)]; } if ([self.tableView respondsToSelector:@selector(setLayoutMargins:)]) { [self.tableView setLayoutMargins:UIEdgeInsetsMake(0, 0, 0, 0)]; } } - (void)tableView:(UITableView*)tableView willDisplayCell:(UITableViewCell*)cell forRowAtIndexPath:(NSIndexPath*)indexPath { if ([cell respondsToSelector:@selector(setSeparatorInset:)]) { [cell setSeparatorInset:UIEdgeInsetsZero]; } if ([cell respondsToSelector:@selector(setLayoutMargins:)]) { [cell setLayoutMargins:UIEdgeInsetsZero]; } } /** 修改分割线缩进为0 */
6.模态控制器的使用:
效果:由下往上弹出一个控制器,覆盖上一个控制器,但原控制器并没有消失
注意点:谁model(present) 谁dismiss
注意:模态控制器有个小问题:见红色部分
// // FirstViewController.m // 模态控制器的小练习 // // Created by 曹魏 on 2016/12/4. // Copyright © 2016年 itcast. All rights reserved. // #import "FirstViewController.h" #import "SecondViewController.h" @interface FirstViewController () @end @implementation FirstViewController - (void)viewDidLoad { [super viewDidLoad]; self.view.backgroundColor = [UIColor redColor]; } #pragma mark -- 点击屏幕跳转界面 - (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{ SecondViewController *second = [[SecondViewController alloc]init];
//下面这个方法是模态时的样式选择,是个枚举,我想说的是枚举方法四中的
UIModalTransitionStylePartialCurl
翻转效果是很特殊的,当我选择这个效果样式时,模态到另一个控制器,再点击界面上任何一点是可以回去的,但别的样式方法不行.
// second.modalTransitionStyle = UIModalTransitionStylePartialCurl; /* typedef NS_ENUM(NSInteger, UIModalTransitionStyle) { UIModalTransitionStyleCoverVertical = 0, UIModalTransitionStyleFlipHorizontal __TVOS_PROHIBITED, UIModalTransitionStyleCrossDissolve, UIModalTransitionStylePartialCurl NS_ENUM_AVAILABLE_IOS(3_2) __TVOS_PROHIBITED, }; */ second.modalTransitionStyle = UIModalTransitionStylePartialCurl; UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:second]; [self presentViewController:nav animated:YES completion:nil]; } @end
特别简单,模态控制器是可以同时管理UITabBarController和UINavigationController的,所以更简单了,从一个控制器模态到第二个控制器,第一个控制器失去响应,例如很多
弹窗就是这样的,下举个小小栗子说明一下:
#import "AppDelegate.h" #import "OneViewController.h" @interface AppDelegate () @end @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds]; OneViewController *one = [[OneViewController alloc]init]; self.window.rootViewController = one; [self.window makeKeyAndVisible]; return YES; }
#import "OneViewController.h" #import "TwoViewController.h" @interface OneViewController () @property (weak, nonatomic) IBOutlet UIButton *modal; @end @implementation OneViewController - (void)viewDidLoad { [super viewDidLoad]; } - (IBAction)didClickModal:(UIButton *)sender { TwoViewController *two = [[TwoViewController alloc]init]; UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:two]; [self presentViewController:nav animated:YES completion:^{ }]; }
#import "TwoViewController.h" @interface TwoViewController () @end @implementation TwoViewController - (void)viewDidLoad { [super viewDidLoad]; self.title = @"第二个控制器"; self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"取消" style:UIBarButtonItemStylePlain target:self action:@selector(cancel)]; } - (void)cancel{ #pragma mark -- 以下两种方式都可以进行dismiss操作,one-->nav是present操作过来(模态),self.navigationController dismiss属于理所应当,但其实其子控制器也可以执行操作达到同样的效果 // [self dismissViewControllerAnimated:YES completion:^{ // // }]; [self.navigationController dismissViewControllerAnimated:YES completion:^{ }]; } @end
很简单,注意一下红色字体即可.
iOS中dismissViewController实现多级模态跳转
当我要用到dismiss实现多级模态跳转的时候,即我想从present 顺序是:A->B->C,当我点击C 的时候直接回到A控制器,由于dismiss操作本质上是由上个发出present操作的控制器所发出的,即假设:B控制器采用dismiss方法回到A控制器,在B中我们通常会写:[self dismissViewControllerAnimated:YES completion:nil];这个方法,本质上这个方法的调用其实是A控制器,B中写这个方法会通知A控制器去执行,表面上是B执行,但本质上是A控制器去执行,
还有注意点:当我点击C控制器回到A控制器时肯定要用到block或者代理通知,
也就是说，其实在present多个视图控制器的时候，系统维护了一个栈，以我们现在这个情况为例，从栈底到栈顶依次是A->B->C。当栈中某个位置的视图控制器执行dismissViewController方法的时候，栈中所有在它之上的视图控制器都会被dismiss，不同的是，栈顶的视图控制器将会以动画方式被dismiss，而中间的视图控制器只是简单的remove掉
可以参考官方文档:http://m.blog.csdn.net/article/details?id=50950915
