我在Appdelegate中查看了一个视图，并在其上添加了6个uibutton ..并在每个课程中添加此视图
self.navigationItem.titleView = objAppDelegate.viewForBtn;
当从每个分支回来时，这个视图没有出现。这背后的问题是什么？ 和代码在这里..
在Appdelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];
navcontrller=[[UINavigationController alloc]initWithRootViewController: self.viewController];
viewForBtn=[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320,44)];
viewForBtn.backgroundColor=[UIColor clearColor];
UIButton *loginbtn=[[UIButton alloc]initWithFrame:CGRectMake(160, 7, 45, 25)];
loginbtn.backgroundColor=[UIColor clearColor];
[loginbtn setTitle:@"Login" forState:UIControlStateNormal];
[loginbtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[loginbtn.titleLabel setFont:[UIFont fontWithName:@"Helvetica Bold " size:13]];
[loginbtn addTarget:self action:@selector(loginbtnpressed) forControlEvents:UIControlEventTouchUpInside];
UIButton *sharebtn=[[UIButton alloc]initWithFrame:CGRectMake(210, 7, 25, 30)];
[sharebtn setImage:[UIImage imageNamed:@"sharing11.png"] forState:UIControlStateNormal];
[sharebtn addTarget:self action:@selector(sharebtnpressed) forControlEvents:UIControlEventTouchUpInside];
UIButton *likebtn=[[UIButton alloc]initWithFrame:CGRectMake(240, 0, 25, 44)];
[likebtn setImage:[UIImage imageNamed:@"LikeIt1.png"] forState:UIControlStateNormal];
[likebtn addTarget:self action:@selector(likebtnpressed) forControlEvents:UIControlEventTouchUpInside];
UIButton *optionbtn=[[UIButton alloc]initWithFrame:CGRectMake(270, 0, 25, 44)];
[optionbtn setImage:[UIImage imageNamed:@"detail.png"] forState:UIControlStateNormal];
[optionbtn addTarget:self action:@selector(optionbtnpressed) forControlEvents:UIControlEventTouchUpInside];
UIButton *backbtn=[[UIButton alloc]initWithFrame:CGRectMake(20, 7, 45, 30)];
backbtn.backgroundColor=[UIColor clearColor];
[backbtn setTitle:@"Back" forState:UIControlStateNormal];
[backbtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
[backbtn.titleLabel setFont:[UIFont fontWithName:@"Helvetica Bold" size:14]];
[backbtn addTarget:self action:@selector(backbtnpressed) forControlEvents:UIControlEventTouchUpInside];
UIButton *homebtn=[[UIButton alloc]initWithFrame:CGRectMake(90, 0, 25, 44)];
[homebtn setImage:[UIImage imageNamed:@"uparrow.png"] forState:UIControlStateNormal];
[homebtn addTarget:self action:@selector(homebtnpressed) forControlEvents:UIControlEventTouchUpInside];
[viewForBtn addSubview:loginbtn];
[viewForBtn addSubview:sharebtn];
[viewForBtn addSubview:likebtn];
[viewForBtn addSubview:optionbtn];
[viewForBtn addSubview:backbtn];
[viewForBtn addSubview:homebtn];
self.window.rootViewController = navcontrller;
[self.window makeKeyAndVisible];
return YES;
}
-(void)loginbtnpressed
{
signIn=[[SignInView alloc]init];
[ self.navcontrller pushViewController:signIn animated:YES];
}
-(void)sharebtnpressed
{
NSLog(@"Share button pressed from button class");
}
-(void)likebtnpressed
{
NSLog(@"Like button pressed from button class");
}
-(void)optionbtnpressed
{
NSLog(@"Options button pressed from button class");
}
-(void)backbtnpressed
{
[self.navcontrller popViewControllerAnimated: YES];
}
-(void)homebtnpressed
{
[self.navcontrller popToRootViewControllerAnimated: YES];
}
in ViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
objAppDelegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];
self.navigationItem.titleView.backgroundColor=[UIColor clearColor];
self.navigationItem.titleView = objAppDelegate.viewForBtn;
}
-(IBAction)btnClk:(id)sender
{
SecondViewController *objSecondViewController=[[SecondViewController alloc]init];
[self.navigationController pushViewController:objSecondViewController animated:YES];
}
-(void)viewWillAppear:(BOOL)animated
{
self.navigationItem.titleView.backgroundColor=[UIColor clearColor];
self.navigationItem.titleView = objAppDelegate.viewForBtn;
}
in SecondViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
objAppDelegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];
self.navigationItem.hidesBackButton=YES;
}
-(IBAction)btn1Clk:(id)sender
{
objThirdViewController=[[ThirdViewController alloc]init];
[self.navigationController pushViewController:objThirdViewController animated:YES];
}
-(void)viewDidAppear:(BOOL)animated
{
self.navigationItem.titleView.backgroundColor=[UIColor clearColor];
self.navigationItem.titleView = objAppDelegate.viewForBtn;
}
in ThirdViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
objAppDelegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];
self.navigationItem.hidesBackButton=YES;
}
-(void)viewDidAppear:(BOOL)animated
{
self.navigationItem.titleView.backgroundColor=[UIColor clearColor];
self.navigationItem.titleView = objAppDelegate.viewForBtn;
}