iOS SplitView / 通用帮助需要 xcode 4.2

Question

我刚刚开始学习 Objective-C 和 iOS 开发，在尝试将 iPhone 应用程序迁移到 iPad 时遇到了一些麻烦。

我一直在阅读 Head First iPhone & iPad Development 2nd Edition，但第 7 章“迁移到 iPad”在 xcode 4.2 中已经过时。 该应用程序演示了如何将拆分视图与表格视图和详细信息视图一起使用。
当将 iOS 应用程序目标从 iPhone 更改为 Universal 时，它们会自动创建 MainWindow-iPad.xib。但这在 xcode 4.2 中并没有发生在我身上。我在 AppDelegate 中以编程方式创建了一个 splitview 控制器。代码如下：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        MasterViewController *firstVC = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease];
        self.secondVC = [[[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil] autorelease];

       UINavigationController *firstVCnav = [[[UINavigationController alloc] initWithRootViewController:firstVC] autorelease];
        UINavigationController *secondVCnav = [[UINavigationController alloc] initWithRootViewController:self.secondVC];

       UISplitViewController *splitVC = [[UISplitViewController alloc] init];
        splitVC.viewControllers = [NSArray arrayWithObjects:firstVCnav, secondVCnav, nil];

       self.window.rootViewController= splitVC;
        [self.window makeKeyAndVisible];
        return YES;
    }else {
        MasterViewController *masterViewController = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease];
        self.navigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];
        self.window.rootViewController = self.navigationController;
        [self.window makeKeyAndVisible];
        return YES;
    }
}

拆分视图（表格视图）的左侧表现良好，但是当我在左侧选择不同的行时，我无法更改右侧（详细信息侧）。这是我在 MasterViewController 类中的代码。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        AppDelegate *splitVCdetails = [[AppDelegate alloc] init];
        [splitVCdetails.secondVC drinkChanged:[self.drinks objectAtIndex:indexPath.row]];

    }else {
        if (!self.editing) {
            if (!self.detailViewController) {
                self.detailViewController = [[[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil] autorelease];
            }
            self.detailViewController.drink = [self.drinks objectAtIndex:indexPath.row];
            [self.navigationController pushViewController:self.detailViewController animated:YES];
        }else {
            AddDrinkViewController *editingDrinkVC = [[AddDrinkViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
            editingDrinkVC.drink = [self.drinks objectAtIndex:indexPath.row];
            editingDrinkVC.drinkArray = self.drinks;

            UINavigationController *editingNavCon = [[UINavigationController alloc] initWithRootViewController:editingDrinkVC];

            [self.navigationController presentModalViewController:editingNavCon animated:YES];
            [editingDrinkVC release];
            [editingNavCon release];
        }
    }
}

这是我在 DetailViewController 类中的代码

-(void)refreshView {
    //Set up our UI with the provided drink
    self.drinkTextLabel.text = [self.drink objectForKey:NAME_KEY];
    self.ingredientTextBox.text = [self.drink objectForKey:INGREDIENTS_KEY];
    self.directionTextBox.text = [self.drink objectForKey:DIRECTIONS_KEY];
}

-(void)drinkChanged:(NSDictionary *)newDrink {
    self.drink = newDrink;
    [self refreshView];
}

如果我需要澄清任何事情，请告诉我。

谢谢

Answer 1

我也在阅读“Head First iPhone and iPad Development”。借助 KevinM 的代码 我在没有 xib 的情况下以编程方式创建了一个 UISplitController。这是我的解决方案。

这是我在 AppDelegate.m 开头的代码：

#import "AppDelegate.h"
#import "MasterViewController.h"
#import "DetailViewController.h"

@implementation AppDelegate

@synthesize window = _window;
@synthesize navigationController = _navigationController;
@synthesize splitViewController = splitViewController_;

- (void)dealloc
{
    [_window release];
    [splitViewController_ release];
    [_navigationController release];
    [super dealloc];
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    // Override point for customization after application launch.    
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        MasterViewController *masterViewController = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease];
        UINavigationController *masterNavigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];

        DetailViewController *detailViewController = [[[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil] autorelease];
        UINavigationController *detailNavigationController = [[[UINavigationController alloc] initWithRootViewController:detailViewController] autorelease];

        masterViewController.splitViewDetailView = detailViewController;

        self.splitViewController = [[[UISplitViewController alloc] init] autorelease];
        self.splitViewController.viewControllers = [NSArray arrayWithObjects:masterNavigationController, detailNavigationController, nil];

        self.window.rootViewController = self.splitViewController;
    }
    else {
        MasterViewController *masterViewController = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease];
        self.navigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease];
        self.window.rootViewController = self.navigationController;
    }

    [self.window makeKeyAndVisible];
    return YES;
}

这是我在 MasterViewController.m 中的代码：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (!self.editing) {
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
            [self.splitViewDetailView drinkChanged:[self.drinks objectAtIndex:indexPath.row]];
        }
        else {
            self.detailViewController = [[[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil] autorelease];
            self.detailViewController.drink = [self.drinks objectAtIndex:indexPath.row];
            [self.navigationController pushViewController:self.detailViewController animated:YES];
        }
    }
    else {
        AddDrinkViewController *editingDrinkVC = [[AddDrinkViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
        editingDrinkVC.drink = [self.drinks objectAtIndex:indexPath.row];
        editingDrinkVC.drinkArray = self.drinks;

        UINavigationController *editingNavCon = [[UINavigationController alloc] initWithRootViewController:editingDrinkVC];

        [self.navigationController presentModalViewController:editingNavCon animated:YES];
        [editingDrinkVC release];
        [editingNavCon release];
    }
}

并在第 345 页（方法 refreshView）和第 346 页（属性 splitViewDetailView）添加书中的代码