UITabBarController - more button does not show up

问题

I create my TabBarController programatically, because I want the same Controller in every tab displaying different content. The content is fetched by an ID. I use the storyboard id the same way as one would use initWithNibName:.

I do this in the AppDelegate:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone" bundle:nil];

    UITabBarController *tabBarController = [[UITabBarController alloc] init];

    for (int i = 0; i < 7; i++) {
        MyViewController *svc = [storyboard instantiateViewControllerWithIdentifier:@"MyView"];
        [svc setID: i];
        [tabBarController addChildViewController:svc];
    }

    [self.window makeKeyAndVisible];
    [self.window setRootViewController: tabBarController];

    return YES;
}

But the TabBar shows only 5 of the 7 Tabs. This is fine, because only 5 tabs can be visible the same time. Unfortunately the ... More button is not visible. So the last 2 tabs are not accessible.

Does anyone have an idea how to force the More button to show up, or why it does not show up?

Regards!

回答1:

It's not showing up because you are adding viewcontrollers to the tab bar controller using addChildViewController method which is a UIViewController method and not a tab bar controller method. So i think what's happening is the tab bar controller doesn't really know that it has more than 5 view controllers.

If you want the more view controller to show up, set the viewControllers array of the tab bar controller directly. Modify your code to something like below:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
UITabBarController *tabBarController = [[UITabBarController alloc] init];  
NSMutableArray *vcArray = [NSMutableArray array]; 
for (int i = 0; i < 7; i++) {
    ViewController *svc = [storyboard instantiateViewControllerWithIdentifier:@"MyView"];
    [svc setID: i];
    [vcArray addObject:svc];
}
[tabBarController setViewControllers:vcArray]; //This is the important part.
[self.window setRootViewController: tabBarController];
[self.window makeKeyAndVisible];

回答2:

Following is simple example for How can you use UITabBarController

Firsts Create all object of UIViewController and UINavigationController in AppDelegate.h file and use following method of AppDelegate.m

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

    self.viewCon=[[ViewController alloc] init];
    self.navCon=[[UINavigationController alloc] initWithRootViewController:self.viewCon];
    self.navCon.navigationBar.tintColor=[UIColor blackColor];
    self.viewCon.title=@"First View";

    self.fView=[[FirstViewController alloc] init];
    self.FnavCon=[[UINavigationController alloc] initWithRootViewController:self.fView];
    self.FnavCon.navigationBar.tintColor=[UIColor blackColor];

    self.fView.title=@"Secound View";

    self.sView=[[SecoundViewController alloc] init];
    self.SnavCon=[[UINavigationController alloc] initWithRootViewController:self.sView];
    self.SnavCon.navigationBar.tintColor=[UIColor blackColor];
    self.sView.title=@"Third View";
    .
    .
    // create UIViewController and UINavigationController As you need 
    .
    .
    .
    UIImage *img1=[UIImage imageNamed:@"Australia.gif"];
    self.tbItem1=[[UITabBarItem alloc] initWithTitle:@"First Page" image:img1 tag:1];
    self.viewCon.tabBarItem=self.tbItem1;

    UIImage *img2=[UIImage imageNamed:@"Cameroon.gif"];
    self.tbItem2=[[UITabBarItem alloc] initWithTitle:@"Secound Page" image:img2 tag:2];
    self.fView.tabBarItem=self.tbItem2;

    UIImage *img3=[UIImage imageNamed:@"Canada.png"];
    self.tbItem3=[[UITabBarItem alloc] initWithTitle:@"Third Page" image:img3 tag:3];
    self.sView.tabBarItem=self.tbItem3;

    NSMutableArray *viewArr=[[NSMutableArray alloc] init];
    [viewArr addObject:self.navCon];
    [viewArr addObject:self.FnavCon];
    [viewArr addObject:self.SnavCon];


    self.tbCon=[[UITabBarController alloc] init];
    self.tbCon.viewControllers=viewArr;

    [self.window addSubview:tbCon.view];

    [self.window makeKeyAndVisible];

    return YES;
}

来源：https://stackoverflow.com/questions/15383160/uitabbarcontroller-more-button-does-not-show-up

标签

ios

button

uitabbarcontroller