从UIViewController切换到UITabBarController [英] Switching from UIViewController to UITabBarController

问题描述

我试图在UITabBarController之前显示UIViewController 2秒，我知道我必须从我的appdelegate开始。我已经尝试过首先将我的self.window.rootviewcontroller分配给我的UIViewController，并在2秒后将我的self.window.rootviewcontroller重新分配给我的UITabViewController。

Im trying to show a UIViewController for 2 seconds before the UITabBarController, i know i have to make it fromm my appdelegate. Ive tried by first assigning my self.window.rootviewcontroller to my UIViewController and with a scheduled timer after 2 seconds reassigning my self.window.rootviewcontroller to my UITabViewController.

问题就是当我测试它时，我的viewcontroller出现了，但是在2秒之后应用程序崩溃了。

The problem is that when i test it, my viewcontroller shows up, but after the 2 seconds the app crashes.

这是我的LaMetro_88AppDelegate.h

This is my LaMetro_88AppDelegate.h

@interface LaMetro_88AppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate>
{
    UIView *startupView;
    NSTimer *timer;

    UIViewController *LoadingViewController;
    UITabBarController *tabBarController;
}

-(void)changeView;
@property (nonatomic, retain) IBOutlet UIWindow *window;

@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
@property (nonatomic, retain) IBOutlet UIViewController *LoadingViewController;

@end

这是我的LaMetro_88AppDelegate.m

This is my LaMetro_88AppDelegate.m

@implementation LaMetro_88AppDelegate

@synthesize window = _window;
@synthesize tabBarController = _tabBarController;
@synthesize LoadingViewController = _LoadingViewController;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
     self.window.rootViewController = self.LoadingViewController;

    timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(changeView:) userInfo:nil repeats:NO];

    [self.window makeKeyAndVisible];
    return YES;
}

-(void)changeView
{

    self.window.rootViewController = self.tabBarController;  

}

推荐答案

您的应用崩溃，因为你的选择器后面有一个冒号（changeView :)，而方法却没有。只需删除该冒号即可。此外，没有必要为定时器设置一个ivar，甚至不需要将定时器创建分配给任何东西 - 该行只能是：

Your app is crashing because your selector has a colon after it (changeView:) whereas, the method does not. Just delete that colon. Also, there is no need to have a ivar for the timer or even to assign the timer creation to anything -- that line can just be:

[NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(changeView) userInfo:nil repeats:NO];

这篇关于从UIViewController切换到UITabBarController的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！