ios學習：UINavigationController導航

 

文件目錄如下：基本導航順序： root -> First -> Second -> Third。其中，FirstViewController作為 navigation堆棧的rootview

 

1、創建navigation。

如果是想直接把navigation導航作為項目一開始的跟視圖，把RootViewController.h文件里的nav屬性放到AppDelegate.h里即可，再把RootViewController.m文件里的action的代碼復制到 AppDelegate.m里的didFinishLaunchingWithOptions 方法里，最后把 self.window.rootViewController 設置 UINavigationController類型的屬性nav即可

在RootViewController.h文件

#import <UIKit/UIKit.h>
@class FirstViewController;

@interface RootViewController : UIViewController

@property (strong, nonatomic) UINavigationController *nav;

- (IBAction)btnClick:(UIButton *)sender;

@end

 

在RootViewController.m 文件里的隨意一個自定義action里：

- (IBAction)btnClick:(UIButton *)sender {
    
    //創建一個viewcontroller
    FirstViewController *fristview =[[[FirstViewController alloc] init] autorelease];
   
    
    //初始化UINavigationController(方式一)
    self.nav = [[[UINavigationController alloc] initWithRootViewController:fristview] autorelease];
    
    
    //初始化UINavigationController(方式二)
  //  self.nav = [[[UINavigationController alloc] init] autorelease];
  //  [self.nav pushViewController:fristview animated:YES];

    
    //初始化UINavigationController(方式三,失敗,xib文件加載失敗,原因暫時不明)
   // self.nav = [[[UINavigationController alloc] initWithNibName:@"FirstViewController" bundle:nil] autorelease];
    
    
    //跳轉到FirstView頁面
    [self presentViewController:self.nav animated:YES completion:nil];
    
    
    //這種寫法一般用於往view里添加一些小控件,如button  label textField之類的,不適宜用於頁面跳轉
    // [self.view addSubview:self.nav.view];
    
    
}

2、設置viewcontroller的navigationItem屬性和 toolbar、toolbarItem

（1）firstViewcontroller的navigation屬性和toolbarItem屬性。代碼在firstviewcontroller.m的viewdidLoad方法里

每個viewcontroller都有一個navigationItem屬性（只在被加載到導航堆棧里才有效），navigationItem屬性里又有5個屬性：UIBarButtonItem類型的leftBarButtonItem、rightBarButtonItem和backBarButtonItem，NSString類型的title（或者viewcontroller屬性的titleView）、prompt。

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    
    //下面兩句代碼的效果一樣,但貌似設置了navigationItem.title 后 title就會被不起作用了
    self.navigationItem.title =  @"首頁123";
    self.title = @"首頁";
    
    //在title上面再加多一行,但這樣子就會造成導航欄的寬度變寬
  //  self.navigationItem.prompt = @"prompt";
    
    //設置rightbarbuttonitem
    UIBarButtonItem *rightbar = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(btnClick:)] autorelease];

    self.navigationItem.rightBarButtonItem = rightbar;

    //修改backbarbuttonitem的title.這個backbarbutton是顯示在下一個push進來的view的tabbar的左邊的
    //action可以設置為nil,這是的動作就是默認的動作,也就是返回到這個view
    self.navigationItem.backBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle:@"back" style:UIBarButtonItemStylePlain target:self action:nil] autorelease];
    
    
    
    //設置toolbar是否可見(對整個navigation堆棧里的view起作用,起全局作用)
    self.navigationController.toolbarHidden = NO;
    
    UIBarButtonItem *three = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:nil action:nil];
    UIBarButtonItem *four = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:nil action:nil];
    UIBarButtonItem *flexItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    
    //toolbar是整個navigation堆棧里的view共同的,但toolbar上面的items卻是每個view單獨擁有的
    //現在只是設置了當前view的toolbaritem,與其他view的toolbaritme是沒有關系的
    [self setToolbarItems:[NSArray arrayWithObjects:flexItem, three, flexItem, four, flexItem, nil]];
    
    [three release];
    [four release];
    [flexItem release];
   
    
}

頁面效果如下：

 

(2)、secondviewcontroller的navigationItem和toolbarItem

代碼在viewdidLoad方法里

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.

    //設置左右barbutton
    UIBarButtonItem *rightbar = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(gotoThird:)] autorelease];
    
    UIBarButtonItem *leftbar = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(gotoThird:)] autorelease];
    
    self.navigationItem.rightBarButtonItem = rightbar;
    self.navigationItem.leftBarButtonItem = leftbar;
    
    //當前view在navigation堆棧里不是rootview,所以把該viewpush到navigation堆棧里時,tabbar左邊會顯示backbarbutton
    //如果給當前view設置了leftbarbutton,會把把backbarbutton覆蓋掉,想同時顯示兩者,需如下設置:
    self.navigationItem.leftItemsSupplementBackButton = YES;

    
    
    //設置當前view的toolbar可見.因為有可能從一個toolbar不可見的view導航到當前view
    self.navigationController.toolbarHidden = NO;
    
}

效果如下：

 

(3)、thirdviewcontroller的navigationItem和toolbaritem

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.title = @"第三頁";
    // Do any additional setup after loading the view from its nib.
    
    //隱藏當前view的toolbar
    self.navigationController.toolbarHidden = YES;
    
    //設置toolbar
    UIBarButtonItem *rightbar = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(goToRootView)] autorelease];
    
    self.navigationItem.rightBarButtonItem = rightbar;
    
   // NSArray *array = @[@"排骨", @"牛排"];
    
    //設置titleview,會覆蓋title
    UISegmentedControl *segment = [[[UISegmentedControl alloc] initWithItems:@[@"排骨", @"牛扒"] ] autorelease];
    segment.segmentedControlStyle = UISegmentedControlSegmentCenter;
    
    self.navigationItem.titleView = segment;
}

效果如下：

 

barButtonItem的style及效果對應如下：