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根据应用程序首选项加载不同的初始视图?

interface-builder uiviewcontroller xcode cocoa-touch iphone

1

Brandon · 技术社区 · 15 年前

我有一个首选项,设置后,强制应用程序在启动时执行某些同步。

我可以使用ib根据此设置显示不同的初始视图吗?

是否有标准的方法来启用此行为?

1 回复 | 直到 15 年前

1

3

falconcreek 15 年前

假设您的应用程序委托上有一个在同步过程中设置的属性,在初始视图控制器的initWithNibNamed:方法中,检查应用程序委托同步的值,并通过调用 [super initWithNibNamed:@"thisNibInsteadOfThatNib"];

编辑: 根据启动时的某些条件,显示用于启动其他视图的代码

// AppDelegate.h
#import <UIKit/UIKit.h>

@interface AppDelegate : NSObject <UIApplicationDelegate>
{
    UIWindow *window;
    UIViewController *firstViewController;
}
@property {nonatomic, retain} UIWindow *window;
@end

// AppDelegate.m
#import AppDelegate.h
#import ViewControllerOne.h
#import ViewControllerTwo.h

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    BOOL shouldLoadViewOne = \\ some value from preferences

    if (shouldLoadViewOne) {
        firstViewController = [[ViewOneController alloc] initWithNibName:@"ViewOneController" bundle:nil];
    } else {
        firstViewController = [[ViewTwoController alloc] initWithNibName:@"ViewTwoController" bundle:nil];
    }

    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:firstViewController];

    [window addSubView:[navController view]];

    [window makeKeyAndVisible];

    return YES;
}

编辑2:

利用 NSClassFromSting() 并保存FirstViewController的名称以加载到首选项中。

// AppDelegate.h
#import <UIKit/UIKit.h>

@interface AppDelegate : NSObject <UIApplicationDelegate>
{
    UIWindow *window;
    id firstViewController;
}
@property {nonatomic, retain} UIWindow *window;

- (NSString *)firstViewControllerName;

@end

// AppDelegate.m
#import AppDelegate.h
#import ViewControllerOne.h
#import ViewControllerTwo.h

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    NSString *viewControllerName = [self firstViewControllerName];

    firstViewController = [[NSClassFromString(viewControllerName) alloc] initWithNibName:viewControllerName  bundle:nil];

    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:firstViewController];

    [window addSubView:[navController view]];

    [window makeKeyAndVisible];

    return YES;
}

- (NSString *)firstViewControllerName
{
    NSString *defaultViewController = @"ViewOneController";
    NSString *savedFirstViewController = // string retrieved from preferences or other persistent store

    if (!savedFirstViewController)
        return defaultViewController;

    return savedFirstViewController;
}