RootViewController - iPhone

Question

我对iPhone编程很陌生，并试图掌握RootViewController的概念。

场景：

我有三种观点

1. RootViewController -父View
2. SportsViewController -子视图1
3. CricketViewController -子视图2

两个子视图都必须在FullScreenMode中，因此不能使用选项卡条或导航栏。

首先，加载Sub View 1，其中包含一些内容和一个DONE按钮。一旦用户按下“完成”按钮，子视图1就必须被卸载，RootViewController应该加载Sub 2。

查询

我已经成功地显示了SubView 1，当用户点击完成之后，我可以卸载它。但是，我没有得到如何通知子视图1的RootViewController子视图1已经卸载，现在它应该加载子视图2？

提前谢谢

Paras Mendiratta

Answer 1

下面是我尝试使用委托模式的代码。

问题是子视图1 (videoPlayer)无法调用委托方法。:(

ViewSwitcher.h -根控制器

@class VideoPlayer; //Sub View 1
@class LandingPage; //Sub View 2

@protocol viewSwitcherDelegate 

-(void)notifyViewSwitcher;

@end

@interface ViewSwitcher : UIViewController 
{
   id <viewSwitcherDelegate> delegate;
}

@property (nonatomic, retain) VideoPlayer *videoPlayer;
@property (nonatomic, retain) LandingPage *landingPage;

@property(assign) id <viewSwitcherDelegate> delegate;

-(void)loadSecondView;
-(void)delegateSetInSubView;

@end

ViewSwitcher.m -实现

@synthesize videoPlayer;
@synthesize landingPage;
//@synthesize delegate;

// 1.4 -> Declare the delegate constructor
- (id <viewSwitcherDelegate>)delegate
{
    return delegate;
}

// 1.5 -> Declare the setDelegate method
- (void)setDelegate:(id <viewSwitcherDelegate>)v
{
    delegate = v;
}
- (void)viewDidLoad
{
    VideoPlayer *videoController = [[VideoPlayer alloc] initWithNibName:@"VideoPlayer" bundle:nil];
    self.videoPlayer = videoController;
    [self.view insertSubview:videoController.view atIndex:0];
    [videoController release];
    [super viewDidLoad];
}

-(void)loadSecondView
{
    NSLog(@"Call for loading 2nd View");
}

视频Player.h- SubView 1(电影播放器)

@interface VideoPlayer : UIViewController <viewSwitcherDelegate>
{
    ViewSwitcher *viewSwitcher;
    MPMoviePlayerController *videoController;
}

@end

VideoPlayer.m -实现

-(void)notifyViewSwitcher
{
    NSLog(@"notifyViewSwitcher called.");
    //Attempted to call the loadSecondView of ViewSwitcher

我试着调用委托的方法，但是在日志中没有打印.

    [viewSwitcher loadSecondView];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    // Setting the delegate
    viewSwitcher.delegate = self;
    return self;
}

- (void)viewDidLoad
{
    NSString *urlStr = [[NSBundle mainBundle] pathForResource:@"bumper.mp4" ofType:nil];
    NSURL *url = [NSURL fileURLWithPath:urlStr];

    videoController = [[MPMoviePlayerController alloc] initWithContentURL:url];
    videoController.controlStyle = MPMovieControlStyleNone;
    [self.view addSubview:videoController.view];

    videoController.view.frame = CGRectMake(0, 0, 480, 320);
    videoController.fullscreen = YES;

    // Remove the status bar from this view.
    [[UIApplication sharedApplication] setStatusBarHidden:YES animated:UIStatusBarAnimationFade];

    // TODO: This observer needs to be removed.
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(playbackStateChange:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:videoController];

    // Play the video.
    [videoController play];

    [super viewDidLoad];
}

// Receives notification once movie is finished.
-(void)playbackStateChange:(NSNotification*)notification
{
    // TODO: Switch the view.

    NSLog(@"Notification = %@", notification);
    [self notifyViewSwitcher];
}

这里是日志：-

2011-08-03 02:44:47.333 My Video Player[24016:207] Notification = NSConcreteNotification 0x5768280 {name = MPMoviePlayerPlaybackDidFinishNotification; object = <MPMoviePlayerController: 0x5740940>; userInfo = {
    MPMoviePlayerPlaybackDidFinishReasonUserInfoKey = 0;
}}
2011-08-03 02:44:47.337 My Video Player[24016:207] notifyViewSwitcher called.

Answer 2

我认为这里最简单的解决方案是使用UINavigationController并隐藏导航栏。您可以使用-setNavigationBarHidden:animated:隐藏(或显示)导航条。

Answer 3

一种方法是实现像- (void)loadSecondView这样的方法，在卸载第一个视图时做所有您想做的事情。然后int -，您可以这样调用这个方法：[super loadSecondView];，并从superview中删除第一个视图。