如何使用状态恢复来恢复视图控制器的子视图

Posted 2023-03-05

【中文标题】如何使用状态恢复来恢复视图控制器的子视图

【英文标题】：How to restore subview of view controller using state restoration

【发布时间】：2014-05-26 13:28:20

【问题描述】：

我正在使用状态恢复来恢复我的应用程序以前的视图和数据。当在第一个视图控制器中单击一个按钮时，我将推动第二个视图控件。在这种情况下，我能够恢复第二个视图控制器数据。但是如果当在第一个视图控制器中单击按钮时，我将第二个视图控制器视图作为子视图添加到第一个视图控制器，在第二个视图控制器中未调用 encodeRestorableStateWithCoder：和 decodeRestorableStateWithCoder：。无法恢复第二个视图控制器数据。我需要做任何其他配置吗恢复子视图数据？

//Firstviewcontroller

-(IBAction)moveToNextViewController:(id)sender 

 SecondVeiwController *sec_VC=[[SecondVeiwController alloc]initWithNibName:@"SecondVeiwController" bundle:[NSBundle mainBundle ]];
    sec_VC.restorationIdentifier=@"SecondVeiwController";

    [self.view addSubview:tab_cnt_1.view];







//Secondviewcontroller

-(id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil


    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) 
        // Custom initialization
        self.restorationIdentifier=@"Secondviewcontroller";
        self.restorationClass=[self class];
    
    return self;



+(UIViewController *)viewControllerWithRestorationIdentifierPath:(NSArray *)identifierComponents coder:(NSCoder *)coder


    UIViewController * myViewController =
    [[Secondviewcontroller alloc]
     initWithNibName:@"Secondviewcontroller"
     bundle:[NSBundle mainBundle]];

    return myViewController;

【参考方案1】：

ios 似乎没有跟踪子视图，您必须对 SecondViewController 进行编码，然后将其解码并添加为子视图控制器，并将其视图作为子视图。

//FirstViewController

-(void)encodeRestorableStateWithCoder:(NSCoder *)coder 

    [super encodeRestorableStateWithCoder:coder];

    [coder encodeObject:self.childViewControllers[0] forKey:@"childVC"];


-(void)decodeRestorableStateWithCoder:(NSCoder *)coder 

    [super decodeRestorableStateWithCoder:coder];

    UIViewController *v = [coder decodeObjectForKey:@"childVC"];

    [self addChildViewController:v];

    [self.view addSubview:v.view];



//SecondViewController

-(void)encodeRestorableStateWithCoder:(NSCoder *)coder 

    [super encodeRestorableStateWithCoder:coder];

    [coder encodeObject:self.view.backgroundColor forKey:@"bgColor"];


-(void)decodeRestorableStateWithCoder:(NSCoder *)coder 

    [super decodeRestorableStateWithCoder:coder];

    UIColor *bgColor = [coder decodeObjectForKey:@"bgColor"];

    [self.view setBackgroundColor:bgColor];