FirstApp，iphone开发学习总结6，Navigation的使用

如图所示，实现的功能：

 为了展示，我创建一个NavView文件，里面包含3个View：

@interface NavView1 : UIViewController{//代表View1
}
@end

@interface NavView2 : UIViewController {//代表View2
}
@end

@interface NavView3 : UIViewController {//代表View3
}
@end

在NavViewController.m文件中，添加头文件：

#import "NavView.h

- (id)init {
    self = [super init];
    if (self) {
        [self setTitle:@"导航标签"];        
    }
    return self;
}

在- (void)viewDidLoad中实现：在view添加一个按钮，点击后，push View1。

- (void)viewDidLoad
{
    UIButton *navViewBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    navViewBtn.frame = CGRectMake(40.0, 30.0, 240.0, 30.0);
    [navViewBtn setTitle:@"To View1" forState:UIControlStateNormal];
    [navViewBtn addTarget:self action:@selector(pushView:) forControlEvents:UIControlEventTouchUpInside];

    [[self view] addSubview:navViewBtn];
}

按钮事件实现：

- (void)pushView:(id)sender
{
    NavView1 *nv1 = [[NavView1 alloc] init];
    [[self navigationController] pushViewController:nv1 animated:YES];
    [nv1 release];
}

点击按钮后，进入View1，即NavView1，此view拥有一个Button，push至View2：

- (id)init {
    self = [super init];
    if (self) {
        [self setTitle:@"View1"];
    }
    return self;
}

- (void)viewDidLoad
{
    UIButton *navViewBtn1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    navViewBtn1.frame = CGRectMake(40.0, 30.0, 240.0, 30.0);
    [navViewBtn1 setTitle:@"To View2" forState:UIControlStateNormal];
    [navViewBtn1 addTarget:self action:@selector(pushView:) forControlEvents:UIControlEventTouchUpInside];
    
    [[self view] addSubview:navViewBtn1];
}

- (void)pushView:(id)sender
{
    NavView2 *nv2 = [[NavView2 alloc] init];
    [[self navigationController] pushViewController:nv2 animated:YES];
    [nv2 release];
}

当点击按钮，此时，进入View2。

View2做的事比较多：

1. 进入View3

2. 到达RootView

3. 到达View1

首先，创建3个按钮，并执行事件：

- (id)init {
    self = [super init];
    if (self) {
        [self setTitle:@"View2"];
    }
    return self;
}

- (void)viewDidLoad
{
    UIButton *navViewBtn2 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    navViewBtn2.frame = CGRectMake(40.0, 30.0, 240.0, 30.0);
    [navViewBtn2 setTitle:@"Open View3" forState:UIControlStateNormal];
    [navViewBtn2 addTarget:self action:@selector(openView:) forControlEvents:UIControlEventTouchUpInside];
    
    UIButton *navViewBtn21 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    navViewBtn21.frame = CGRectMake(40.0, 80.0, 240.0, 30.0);
    [navViewBtn21 setTitle:@"To Root" forState:UIControlStateNormal];
    [navViewBtn21 addTarget:self action:@selector(popView:) forControlEvents:UIControlEventTouchUpInside];
    
    UIButton *navViewBtn22 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    navViewBtn22.frame = CGRectMake(40.0, 130.0, 240, 30);
    [navViewBtn22 setTitle:@"To View1" forState:UIControlStateNormal];
    [navViewBtn22 addTarget:self action:@selector(popView1:) forControlEvents:UIControlEventTouchUpInside];
    
    [[self view] addSubview:navViewBtn2];
    [[self view] addSubview:navViewBtn21];
    [[self view] addSubview:navViewBtn22];
}

点击第一个“Open View3”按钮时：

//这里使用presentModalViewController，由下弹出。

//创建UINavigationController的作用是进入此时的View，navigation为空，必须新建一个。

- (void)openView:(id)sender
{
    NavView3 *nv3 = [[NavView3 alloc] init];
    UINavigationController *nv = [[UINavigationController alloc] initWithRootViewController:nv3];
    [self presentModalViewController:nv animated:YES];
    [nv release];
    [nv3 release];
}

点击第二个“To Root”按钮时：//直接进入RootView，此处要检查navigationController是否存在。

- (void)popView:(id)sender
{
    [[self navigationController] popToRootViewControllerAnimated:YES];
}

点击第三个“To View1”按钮时，后推一位：

- (void)popView1:(id)sender
{
    [[self navigationController] popViewControllerAnimated:YES];
}

 //还有一种– popToViewController:animated:，总体类似，参考

差不多都实现了 ，就剩下如何关闭View3了。NavView3的实现：

- (id)init {
    self = [super init];
    if (self) {
        [self setTitle:@"View3"];
    }
    return self;
}

为了美观点，将按钮添加到Navigation的左边并添加一个Label显示此处为View3：

- (void)viewDidLoad
{
    UILabel *navViewLbl3 = [[UILabel alloc] initWithFrame:CGRectMake(110.0, 100.0, 100.0, 30.0)];
    navViewLbl3.text = @"View3 Here!!";
    navViewLbl3.font = [UIFont fontWithName:@"" size:20];
    [[self view] addSubview:navViewLbl3];
    
    UIBarButtonItem *navViewBtn3 = [[UIBarButtonItem alloc] initWithTitle:@"Close" style:UIBarButtonItemStyleDone target:self action:@selector(closeView:)];
    [self.navigationItem setLeftBarButtonItem:navViewBtn3];
}

事件实现：

- (void)closeView:(id)sender
{
    [self dismissModalViewControllerAnimated:YES];
}

持续完善，求指点。

 

To 6 code download：iOS_FirstApp_6.zip