Question

我的标签栏中的标签似乎没有显示出来。这是我的App Delegate代码：

（应用程序名称）AppDelegate.h：

    #import <UIKit/UIKit.h>

    @class TwitterViewContoller;

    @interface <appname>AppDelegate : NSObject <UIApplicationDelegate> {
        UIWindow *window;
        UITabBarController *rootController;
        TwitterViewContoller *viewController;
        NSMutableData *responseData;
        NSMutableArray *tweets;
    }

    @property (nonatomic, retain) IBOutlet UIWindow *window;
    @property (nonatomic, retain) IBOutlet UITabBarController *rootController;
    @property (nonatomic, retain) IBOutlet TwitterViewContoller *viewController;
    @property (nonatomic, retain) NSMutableArray *tweets;

    @end

（应用程序名称）AppDelegate.m：

    #import "<appname>AppDelegate.h"
    #import "TwitterViewContoller.h"
    #import "SBJson.h"

    @implementation <appname>AppDelegate

    @synthesize window = _window;
    @synthesize rootController;
    @synthesize viewController;
    @synthesize tweets;

    #pragma mark -
    #pragma mark Application lifecycle

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
        // Override point for customization after application launch. 
        CGFloat width = self.rootController.view.bounds.size.width;
        CGFloat height = self.rootController.view.bounds.size.height;
        UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, width, height)];
        UIImage *imageView = [UIImage imageNamed:@"TabBarBackground.png"];
        UIColor *kMainColor = [[UIColor alloc] initWithPatternImage:imageView];

        [v setBackgroundColor:kMainColor];
        [kMainColor release];

        [self.rootController.tabBar insertSubview:v atIndex:0];
        [imageView release];
        [v release];

        responseData = [[NSMutableData data] retain];
        tweets = [NSMutableArray array];

        NSURLRequest *request = [NSURLRequest requestWithURL:
                         [NSURL URLWithString:@"http://api.twitter.com/1/statuses/user_timeline.json?screen_name=USER_NAME_ID"]];

        [[NSURLConnection alloc] initWithRequest:request delegate:self];
                NSAssert(nil != self.rootController, @"tab bar controller not hooked up!");

        self.viewController = [[[TwitterViewContoller alloc] initWithNibName:@"TwitterViewContoller_iPhone" bundle:nil] autorelease];
        self.rootController.viewControllers = [NSArray arrayWithObject:self.viewController];

        // this is now the Right Way to set the root view for your app, in iOS 4.0 and later
        self.window.rootViewController = self.rootController;

        [self.window makeKeyAndVisible];
        return YES;
    }

    #pragma mark NSURLConnection delegate methods
    - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
        [responseData setLength:0];
    }

    - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
        [responseData appendData:data];
    }

    - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    }

    - (void)connectionDidFinishLoading:(NSURLConnection *)connection {
        [connection release];
        NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
        [responseData release];

        NSArray *allTweets = [responseString JSONValue];
        [viewController setTweets:allTweets];

    }

    - (void)dealloc {
        [_window release];
        [rootController release];
        [viewController release];
        [super dealloc];
    }

    @end

我认为问题出在application didFinishLaunchingWithOptions:，因为我对App Delegate最近的唯一更改就是这些：

    NSAssert(nil != self.rootController, @"tab bar controller not hooked up!");

    self.viewController = [[[TwitterViewContoller alloc] initWithNibName:@"TwitterViewContoller_iPhone" bundle:nil] autorelease];
    self.rootController.viewControllers = [NSArray arrayWithObject:self.viewController];

    // this is now the Right Way to set the root view for your app, in iOS 4.0 and later
    self.window.rootViewController = self.rootController;
    [self.window makeKeyAndVisible];

（编辑：删除上面的第2行和第3行修复了问题，但我需要它们）。有什么想法吗？

Answer 1

创建其他ViewControllers的属性并在实现文件（.m）中合成它们。也可以在AppDelegate.m文件中导入它们。这是你的标题（.h）文件的样子（rootController是你的TabBarController）：

    #import <UIKit/UIKit.h>

    @class TwitterViewContoller;
    @class OtherViewController;

    @interface <appname>AppDelegate : NSObject <UIApplicationDelegate> {
        UIWindow *window;
        UITabBarController *rootController;
        TwitterViewContoller *viewController;
        OtherViewController *viewController1;
    }

    @property (nonatomic, retain) IBOutlet UIWindow *window;
    @property (nonatomic, retain) IBOutlet UITabBarController *rootController;
    @property (nonatomic, retain) IBOutlet TwitterViewContoller *viewController;
    @property (nonatomic, retain) IBOutlet OtherViewController *viewController1;

    @end

您的实现（.m）文件的前几行：

#import "<appname>AppDelegate.h"
#import "TwitterViewContoller.h"
#import "OtherViewController.h"

@implementation <appname>AppDelegate

@synthesize window = _window;
@synthesize rootController;
@synthesize viewController;
@synthesize viewController1;

为所有ViewControllers添加额外的alloc和inits：

self.viewController = [[[TwitterViewContoller alloc] initWithNibName:@"TwitterViewContoller_iPhone" bundle:nil] autorelease];
self.viewController1 = [[[SecondViewController alloc] initWithNibName:@"SecondViewController_iPhone" bundle:nil] autorelease];

然后替换它：

self.rootController.viewControllers = [NSArray arrayWithObject:self.viewController];

用这个：

self.rootController.viewControllers = [NSArray arrayWithObjects:self.viewController, self.viewController1, nil];

这样您就可以向TabBar控制器添加多个UIViewController。

当然，发布：

[viewController release];
[viewController1 release];

在ViewControllers的每个类下，在-initWithNibName方法下，在if (self)语句中添加：

UITabBarItem *tabBarItem = [self tabBarItem];
UIImage *tabBarImage = [UIImage imageNamed:@"IMAGE NAME.png"];
[tabBarItem setImage:tabBarImage];
[tabBarItem setTitle:@"TITLE GOES HERE"];

运行你的应用程序，它现在应该正常工作！

iOS（iPhone / iPad）SDK - 标签栏中的标签未显示

1 个答案: