怎樣的UIViewController和UIView的

Question

之間協調我是相當新的iOS開發，我不能夠環繞一個概念我的頭..

我有兩個UIViewController類 - ViewController和SecondViewController。最初，文件的ViewController類被加載，其中僅包含UIButton。當點擊此按鈕時，SecondViewController開始起作用，它需要加載由我的UIView類創建的視圖，該類名爲ViewClass。 ViewClass只包含一個UIButton。

單擊ViewController xib上的按鈕，我所得到的只是一個黑屏，我不明白爲什麼loadView和viewDidLoad方法會被調用很多次。（輸出如下所示）！

這裏是我的代碼..

ViewController.m

@implementation ViewController 
@synthesize secondViewController = _secondViewController; 

-(id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
{ 
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 
    if(self) 
    { 
     NSLog(@"init of ViewController called"); 
     self.secondViewController = [[SecondViewController alloc] init]; 
    } 
    return self; 
} 

- (IBAction)buttonPressed:(id)sender { 
    [self presentViewController:self.secondViewController animated:YES completion:NULL]; 
    NSLog(@"presented"); 
} 

SecondViewController.m

-(void)loadView 
{ 
    NSLog(@"loadView Called"); 
    self.myView = [[ViewClass alloc] init]; 
    [self.view addSubview:self.myView]; 
} 

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
{ 
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 
    if (self) { 
     NSLog(@"init of SVC called"); 
    } 
    return self; 
} 

-(void)viewWillAppear:(BOOL)animated 
{ 
    NSLog(@"view WIll appear called"); 
} 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    NSLog(@"view did load called"); 
} 

ViewClass.m

- (id)initWithFrame:(CGRect)frame 
{ 
    self = [super initWithFrame:frame]; 
    if (self) { 
     NSLog(@"init OF View Called"); 
     UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
     button.titleLabel.text = @"Heyy"; 
     [self addSubview:button]; 
    } 
    return self; 
} 

，這就是我得到的控制檯..

2013-10-04 11:03:08.454 MVCPractice1[30957:a0b] Cannot find executable for CFBundle 0xa894b30 </Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk/System/Library/AccessibilityBundles/CertUIFramework.axbundle> (not loaded) 
2013-10-04 11:03:08.503 MVCPractice1[30957:a0b] init of ViewController called 
2013-10-04 11:03:08.504 MVCPractice1[30957:a0b] init of SVC called 
2013-10-04 11:03:09.773 MVCPractice1[30957:a0b] loadView Called 
2013-10-04 11:03:09.774 MVCPractice1[30957:a0b] init OF View Called 
2013-10-04 11:03:09.775 MVCPractice1[30957:a0b] view did load called 
2013-10-04 11:03:09.776 MVCPractice1[30957:a0b] loadView Called 
2013-10-04 11:03:09.777 MVCPractice1[30957:a0b] init OF View Called 
2013-10-04 11:03:09.778 MVCPractice1[30957:a0b] view did load called 
2013-10-04 11:03:09.779 MVCPractice1[30957:a0b] loadView Called 
2013-10-04 11:03:09.779 MVCPractice1[30957:a0b] init OF View Called 
2013-10-04 11:03:09.780 MVCPractice1[30957:a0b] view did load called 
2013-10-04 11:03:09.781 MVCPractice1[30957:a0b] loadView Called 
2013-10-04 11:03:09.781 MVCPractice1[30957:a0b] init OF View Called 
2013-10-04 11:03:09.782 MVCPractice1[30957:a0b] view did load called 
2013-10-04 11:03:09.783 MVCPractice1[30957:a0b] view WIll appear called 
2013-10-04 11:03:09.783 MVCPractice1[30957:a0b] loadView Called 
2013-10-04 11:03:09.784 MVCPractice1[30957:a0b] init OF View Called 
2013-10-04 11:03:09.785 MVCPractice1[30957:a0b] view did load called 
2013-10-04 11:03:09.785 MVCPractice1[30957:a0b] loadView Called 
2013-10-04 11:03:09.786 MVCPractice1[30957:a0b] init OF View Called 
2013-10-04 11:03:09.787 MVCPractice1[30957:a0b] view did load called 
2013-10-04 11:03:09.787 MVCPractice1[30957:a0b] presented 

Answer 1

的loadView工作是設定self.view到一個視圖。當您收到loadView消息時，self.view爲零。從某處獲取視圖（通過在代碼中創建視圖或加載筆尖）並將該視圖存儲在self.view中是您的工作。

的loadView方法必須設置self.view到一個視圖返回前，和不得設置self.view他self.view吸氣之前通話噸。試試這個：

-(void)loadView { 
    NSLog(@"loadView Called"); 
    self.view = [[ViewClass alloc] init]; 
} 

Answer 2

也請在viewDidLoad中的初始化當你正在處理的UIViewController這將是一個很好的做法。

-(id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
{ 
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 
    if(self) 
    { 
     NSLog(@"init of ViewController called"); 

    } 
    return self; 
} 
- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    NSLog(@"view did load called"); 
    self.secondViewController = [[SecondViewController alloc] init]; 
} 

也改變的loadView方法搶劫mayoff解釋..