Question

我在我的项目中创建了一个UIViewController的子类，并将它链接到一个由“RootViewController”模式推送的View。我绝对没有对派生类进行任何更改，但是当按下“SecondView”时，它每次都变黑。如果我将该视图链接到标准的UIViewController类，一切正常吗？

由于“SecondViewController”派生自UIViewController，我只能猜测问题与alloc / init函数有关，但我不知道从哪里开始。

如有必要，我现在可以提供我面前的示例代码。

这是派生的子类：

#import "SecondViewController.h"

@interface SecondViewController ()

@end

@implementation SecondViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self; }

- (void)loadView {}

- (void)viewDidLoad {
    [super viewDidLoad]; }

- (void)viewDidUnload {
    [super viewDidUnload];}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return (interfaceOrientation == UIInterfaceOrientationPortrait); }

@end

部首：

#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController

@end

Answer 1

- (void)loadView
{
    // If you create your views manually, you MUST override this method and use it to create your views.
    // If you use Interface Builder to create your views, then you must NOT override this method.
}

仅供参考，评论也会自动生成。

Answer 2

改变这个：

- (void)loadView
{
    // If you create your views manually, you MUST override this method and use it to create your views.
    // If you use Interface Builder to create your views, then you must NOT override this method.
}

对此：

- (void)loadView
{
    [super loadView];
    // If you create your views manually, you MUST override this method and use it to create your views.
    // If you use Interface Builder to create your views, then you must NOT override this method.
}

它会起作用。

Answer 3

试试这个

-(void)loadView
{
    UIView *view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].applicationFrame]; 

    [view setBackgroundColor:[UIColor whiteColor]];

    UILabel *label=[[UILabel alloc]initWithFrame:CGRectMake(10, 50, 100, 100)];

    [label setText:@"HAI"];

    [view addSubview:label];

    self.view = view; 
}

Answer 4

如果你试图在IB的segue中“显示”之前加载视图，你可能想在目标视图控制器中尝试这样的事情。

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
[self.view layoutIfNeeded];
}

UIViewController的子类显示黑屏

4 个答案: