Question

在我的Swift 3 / Obj-C应用程序中，我无法显示一个快速视图控制器，它是和Obj-C类的子类。

以下代码完美无缺：

NavigationController.swift

func myMethod(){
    ...
    let vc = ParentViewController.init(someParameter: parameter) // << results in desired screen
    vc?.stringProperty = "someString"
    self.pushViewController(vc!, animated: true)
}

SuperParentViewController.h

@interface SuperParentViewController : UIViewController 
     @property (nonatomic, strong) NSString *stringProperty;
     - (instancetype)initWithSomeParameter:(SomeClass *)someParameter;
@end

ParentViewController.h

@interface ParentViewController : SuperParentViewController
     // numerous properties are declared here
@end

ParentViewController.m

@implementation ParentViewController
    ...

    - (void)viewDidLoad{
        [super viewDidLoad];
        // a bunch of properties are set
    }

    - (void)viewWillAppear:(BOOL)animated{
        [super viewWillAppear:animated];
        // more properties are set
    }

    ...
@end

但是，如果我将ParentViewController子类化并尝试呈现子类“SubclassViewController”，则会生成仅显示导航栏项的屏幕;屏幕的其余部分为空白：

NavigationController.swift

func myMethod(){
    ...
    let vc = SubClassedViewController.init(someParameter: parameter) // << results in blank screen
    vc?.stringProperty = "someString"
    self.pushViewController(vc!, animated: true)
}

SubClassedViewController.swift

class SubClassedViewController: ParentViewController
{
    // nothing in this file yet
}

有人可以告诉我为什么SubClassedViewController无法显示ParentViewController的相同内容吗？

Answer 1

问题是ParentViewController与.xib文件相关联（单击.xib文件 - ＆gt;转到识别检查器 - ＆gt;在自定义类下，您将找到“ParentViewController”）。因此，当子类化ParentViewController来创建SubClassedViewController类时，我还需要使用以下代码来初始化相同的.xib文件：

（Swift 3）

class SubClassedViewController: ParentViewController
{    
    override init(someParameter: someClass) {
        super.init(nibName: "ParentViewController", bundle: nil)
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
}

swift 3 - 未显示子类视图控制器

1 个答案: