第十章 UINavigationController 翻译

一，可以用于创建有关联关系的页面

二，UINavigationController

        1，UINavigationController维护一个多屏幕的堆栈，每个screen都是一个viewController

        2，UINavigationController继承于viewController，它的view属性包含一个UINavigationBar和topViewController的view；

        3，可以直接将UINavigationController添加到window中，这样也可以做到UINavigationController的切换

        

- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds]];
// Override point for customization after application launch
BNRItemsViewController *itemsViewController
= [[BNRItemsViewController alloc] init];
// Create an instance of a UINavigationController
// its stack contains only itemsViewController
UINavigationController *navController = [[UINavigationController alloc]
initWithRootViewController:itemsViewController];
// Place navigation controller's view in the window hierarchy
self.window.rootViewController = navController;
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}

四，使用UINavigationController进行页面导航

       1，初始化UINavigationController必须有一个controller

       2，可以使用controller的navigationController访问UINavigationController

       3，可以使用navigationController的pushViewController:animated:添加一个controller

@implementation BNRItemsViewController
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
BNRDetailViewController *detailViewController =
[[BNRDetailViewController alloc] init];
// Push it onto the top of the navigation controller's stack
[self.navigationController pushViewController:detailViewController
animated:YES];
}

       4，所有加入到navigationController的controller构成一个堆栈关系

五，在controller之间传递数据

        1，可以直接在controller之间传递数据

        2，一般可以将数据都放在root controller中，并传递到下一级的controller

- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
BNRDetailViewController *detailViewController =
[[BNRDetailViewController alloc] init];
NSArray *items = [[BNRItemStore sharedStore] allItems];
BNRItem *selectedItem = items[indexPath.row];
// Give detail view controller a pointer to the item object in row
detailViewController.item = selectedItem;
[self.navigationController pushViewController:detailViewController
animated:YES];
}

       

六，隐藏或显示views

        1，使用[self.view endEditing:YES];来释放focus，并隐藏键盘

        2，使用self.tableView reloadData来刷新tableView的显示

七，UINavigationBar

        1，UIViewController有一个UINavigationItem的属性，navigationController使用它来初始化导航条

        2，手动创建action连接

               

- (instancetype)init
{
self = [super initWithStyle:UITableViewStylePlain];
if (self) {
UINavigationItem *navItem = self.navigationItem;
navItem.title = @"Homepwner";
// Create a new bar button item that will send
// addNewItem: to BNRItemsViewController
UIBarButtonItem *bbi = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:@selector(addNewItem:)];
// Set this bar button item as the right item in the navigationItem
navItem.rightBarButtonItem = bbi;
}
return self;
}

       3，连接编辑模式

             navItem.leftBarButtonItem = self.editButtonItem;

             viewController访问editButtonItem时候，会创建并返回UIBarButtonItem

       4，UINavigationItem不是一个view

一，可以用于创建有关联关系的页面

二，UINavigationController

        1，UINavigationController维护一个多屏幕的堆栈，每个screen都是一个viewController

        2，UINavigationController继承于viewController，它的view属性包含一个UINavigationBar和topViewController的view；

        3，可以直接将UINavigationController添加到window中，这样也可以做到UINavigationController的切换

        

- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds]];
// Override point for customization after application launch
BNRItemsViewController *itemsViewController
= [[BNRItemsViewController alloc] init];
// Create an instance of a UINavigationController
// its stack contains only itemsViewController
UINavigationController *navController = [[UINavigationController alloc]
initWithRootViewController:itemsViewController];
// Place navigation controller's view in the window hierarchy
self.window.rootViewController = navController;
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}

四，使用UINavigationController进行页面导航

       1，初始化UINavigationController必须有一个controller

       2，可以使用controller的navigationController访问UINavigationController

       3，可以使用navigationController的pushViewController:animated:添加一个controller

@implementation BNRItemsViewController
- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
BNRDetailViewController *detailViewController =
[[BNRDetailViewController alloc] init];
// Push it onto the top of the navigation controller's stack
[self.navigationController pushViewController:detailViewController
animated:YES];
}

       4，所有加入到navigationController的controller构成一个堆栈关系

五，在controller之间传递数据

        1，可以直接在controller之间传递数据

        2，一般可以将数据都放在root controller中，并传递到下一级的controller

- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
BNRDetailViewController *detailViewController =
[[BNRDetailViewController alloc] init];
NSArray *items = [[BNRItemStore sharedStore] allItems];
BNRItem *selectedItem = items[indexPath.row];
// Give detail view controller a pointer to the item object in row
detailViewController.item = selectedItem;
[self.navigationController pushViewController:detailViewController
animated:YES];
}

       

六，隐藏或显示views

        1，使用[self.view endEditing:YES];来释放focus，并隐藏键盘

        2，使用self.tableView reloadData来刷新tableView的显示

七，UINavigationBar

        1，UIViewController有一个UINavigationItem的属性，navigationController使用它来初始化导航条

        2，手动创建action连接

               

- (instancetype)init
{
self = [super initWithStyle:UITableViewStylePlain];
if (self) {
UINavigationItem *navItem = self.navigationItem;
navItem.title = @"Homepwner";
// Create a new bar button item that will send
// addNewItem: to BNRItemsViewController
UIBarButtonItem *bbi = [[UIBarButtonItem alloc]
initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:@selector(addNewItem:)];
// Set this bar button item as the right item in the navigationItem
navItem.rightBarButtonItem = bbi;
}
return self;
}

       3，连接编辑模式

             navItem.leftBarButtonItem = self.editButtonItem;

             viewController访问editButtonItem时候，会创建并返回UIBarButtonItem

       4，UINavigationItem不是一个view