视图之间的数据UIApplication [英] data between Views UIApplication

问题描述

我想在视图之间共享数据...

我有tabbar应用程序的appdelegate：

myappdelegate.h

  #import< UIKit / UIKit .h> 
 
 @interface myappdelegate：NSObject< UIApplicationDelegate，UITabBarControllerDelegate> {
 UIWindow * window; 
 UITabBarController * tabBarController; 
 NSString * result; 
} 
 
 
 @property（非原子，保留）IBOutlet UIWindow *窗口; 
 @property（nonatomic，retain）IBOutlet UITabBarController * tabBarController; 
 
 @property（copy，readwrite）NSString * result; 
 
 
 @end 
  

如果我想用这个命令，有提示：可能不回应....

  myappdelegate * dataCenter = [（myappdelegate *）[ UIApplication sharedApplication] delegate]; <<可以不响应
 dataCenter.result = @msg; 
 
 result_view * resultView = [[result_view alloc] initWithNibName：@result_viewbundle：nil]; 
 [self.navigationController pushViewController：resultView animated：YES]; 
 [resultView release]; 
  

result_view.m

   - （void）viewDidLoad 
 {
 myappdelegate * dataCenter =（myappdelegate *）[[UIApplication sharedApplication] delegate] ; 
 
 [label setText：dataCenter.result]; 
 [super viewDidLoad]; 
 //从其笔尖加载视图后，请执行任何其他设置。 
} 
  

程序崩溃...

解决方案

你的代码是说 sharedApplication 是类 myappdelegate ，确实没有回应委托。这样做：

 （myappdelegate *）[[UIApplication sharedApplication] delegate]; 
  

删除警告。

---

由于Objective-C的运行时消息传递，您当前的（警告生成）代码不会崩溃应用程序。崩溃在别的地方。

i want to share data between views...

i have the appdelegate of tabbar application:

myappdelegate.h

#import <UIKit/UIKit.h>

@interface myappdelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {
    UIWindow *window;
    UITabBarController *tabBarController;
    NSString  *result;
}


@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;

@property (copy , readwrite) NSString *result;


@end

if i want to call with this command, there is the hint: "may not respond"....

   myappdelegate *dataCenter = [(myappdelegate *)[UIApplication sharedApplication] delegate];  <<may not respond
   dataCenter.result = @"msg";

result_view *resultView = [[result_view alloc] initWithNibName:@"result_view" bundle:nil];
[self.navigationController pushViewController:resultView animated:YES];
[resultView release];

result_view.m

- (void)viewDidLoad
{
    myappdelegate *dataCenter = (myappdelegate*)[[UIApplication sharedApplication]delegate];

    [label setText:dataCenter.result];
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
}

the program crashes...

解决方案

Your code is saying that the sharedApplication is of the class myappdelegate, which indeed does not respond to delegate. Do this:

(myappdelegate *)[[UIApplication sharedApplication] delegate];

to remove the warning.

---

Due to Objective-C's runtime messaging, your current (warning-generating) code won't crash the app. The crash lies somewhere else.

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