初始化后在视图控制器中加载/刷新新数据

Question

我有一个建筑类，其中包含建筑信息（字符串）。当我推动我的DetailViewController（不是从一个tableviewcontroller），我推它的建筑selcyed它加载在正确的信息。我想要做的是在下一个建筑物实例中加载的详细视图上有一个按钮。我尝试了以下，但没有运气 - 所有数据都为空/空。我不能正确地连接到我的建筑物。

在我mainViewController

-(IBAction)pushDetailsVC:(id)sender { 

    DetailViewController* controller = [[DetailViewController alloc] init]; 
    // Pass the Building object to the controller 
    building = [self.buildings objectAtIndex:nsu_selBldg]; 
    controller.building = building; 
    NSLog(@"Building name is now: %@", building); 
    [self presentModalViewController:controller animated:YES]; 
    [controller.uib_backButton addTarget:self action:@selector(close:) forControlEvents:UIControlEventTouchUpInside]; 
    [controller release]; 
} 

在我DetailViewController // h的

@property (nonatomic, retain) Building *building; 
@property (nonatomic, retain) PhotoViewerViewController *photoVC; 

// m的

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // This works as expected - the data loads in great. 
    self.uill_bldgName.text = self.building.name; 
    self.uitt_bldgInfo.text = self.building.bldgInfo; 
    self.uiivv_bldgPlan.image = [UIImage imageNamed:self.building.bldgPlan]; 
    self.uiivv_bldgImage.image = [UIImage imageNamed:self.building.bldgImageZoom]; 
    NSLog(@"first name%@",self.building.bldgImageZoom); 
} 

-(IBAction)nextBldg { 
    // This does not work - data goes null. PhotoVC is my main view controller and buildings is the array of buildings 
    building = [photoVC.buildings objectAtIndex:2]; 
    Building *building = building; 
    NSLog(@"building %@",building); 
    NSLog(@"building %@",[photoVC.buildings objectAtIndex:2]); 
    self.uill_bldgName.text = self.building.name; 
    self.uitt_bldgInfo.text = self.building.bldgInfo; 
    self.uiivv_bldgPlan.image = [UIImage imageNamed:self.building.bldgPlan]; 
    self.uiivv_bldgImage.image = [UIImage imageNamed:self.building.bldgImageZoom]; 
    NSLog(@"secon name %@",self.building.bldgImageZoom);  
} 

Answer 1

我没有看到你在哪里初始化photoVC。没有初始化，你一定没有建筑数据。

更好的方法是将您的建筑物数组（和当前索引nsu_selBldg）传递给DetailViewController。然后它将可以访问任何想要的建筑物。

// DetailVC.h 

@property (nonatomic, retain) NSArray *buildings; 
@property (nonatomic, assign) NSUInteger currentIndex; 

// DetailVC.m 

Building *currentBuilding = [self.buildings objectAtIndex:self.currentIndex]; 
NSUInteger nextIndex = (self.currentIndex == self.buildings.count-1)? 0 : self.currentIndex+1; 
Building *nextBuilding = [self.buildings objectAtIndex:nextIndex];