IOS开发之——Modal原理和常规使用(65)

一 概述

• 除了push之外，还有另外一种控制器的切换方式，那就是Modal
• 任何控制器都能通过Modal的形式展示出来
• Modal的默认效果：新控制器从屏幕的最底部往上钻，知道盖住之前的控制器为止

二 Modal的打开及关闭

2.1 Modal形式展示控制器

-(void)presentViewCOntroller:(UIViewCOntroller *)viewCOntrollerToPresent animated:(BOOL)flag completion:(void^)completion

2.2 关闭Modal出来的控制器

self dismissViewControllerAnimated:<#(BOOL)#> completion:<#^(void)completion#>

三 简单示例

3.1 界面关系

• FirstVIewController(第一个页面)，有一个按钮，点击跳转到JumpViewController
• JumpViewController(跳转到的页面)，有一个返回按钮，点击返回到FirstViewController

3.2 代码

FirstVIewController

- (void)viewDidLoad {
    [super viewDidLoad];
    UIButton *btn=[UIButton buttonWithType:UIButtonTypeContactAdd];
    btn.center=self.view.center;
    [btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
}
-(void)btnClick{
    //创建控制器对象
    JumpViewController *jump=[[JumpViewController alloc]init];
    //Modal出一个控制器
    //[self presentModalViewController:jump animated:YES];
     
    [self presentViewController:jump animated:YES completion:nil];
}

JumpViewController

- (IBAction)cancel:(UIButton *)sender {
    //关闭
    [self dismissViewControllerAnimated:YES completion:nil];
}

3.3 效果图

四 通过导航条方式关闭Modal

4.1 界面修改说明

• 去掉JumpViewController中去掉按钮
• 通过导航条做按钮做返回操作

4.2 代码

FirstVIewController

- (void)viewDidLoad {
    [super viewDidLoad];
    UIButton *btn=[UIButton buttonWithType:UIButtonTypeContactAdd];
    btn.center=self.view.center;
    [btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
}
-(void)btnClick{
    //创建控制器对象
    JumpViewController *jump=[[JumpViewController alloc]init];
    //Modal出一个控制器
    //[self presentModalViewController:jump animated:YES];
    UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:jump];
     
    [self presentViewController:nav animated:YES completion:nil];
}

JumpViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithTitle:@"取消" style:UIBarButtonItemStyleDone target:self action:@selector(cancel)];  
}
- (IBAction)cancel{
    //关闭
    [self dismissViewControllerAnimated:YES completion:nil];
}

4.3 效果图