未声明的错误和iPhone模拟器崩溃

Question

这是我的代码： delegate.h

#import <UIKit/UIKit.h>

@class _4_Control_FunViewController;

@interface _4_Control_FunAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
_4_Control_FunViewController *viewController;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet _4_Control_FunViewController *viewController;

@end

delegate.m：

#import "_4_Control_FunAppDelegate.h"
#import "_4_Control_FunViewController.h"

@implementation _4_Control_FunAppDelegate

@synthesize window;
@synthesize viewController;


#pragma mark -
#pragma mark Application lifecycle

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:    (NSDictionary *)launchOptions {    

[window addSubview:viewController.view];
[window makeKeyAndVisible];

return YES;
}


 - (void)applicationWillResignActive:(UIApplication *)application {

}


- (void)applicationDidEnterBackground:(UIApplication *)application {

}


- (void)applicationWillEnterForeground:(UIApplication *)application {

}


 - (void)applicationDidBecomeActive:(UIApplication *)application {

}


- (void)applicationWillTerminate:(UIApplication *)application {

}


#pragma mark -
#pragma mark Memory management

- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application {

}


- (void)dealloc {
[viewController release];
[window release];
[nameField release];
[numberField release];
[super dealloc];
}

@end

ViewController.h

#import <UIKit/UIKit.h>

@interface _4_Control_FunViewController : UIViewController {
UITextField *nameField;
UITextField *numberField;
}
@property (nonatomic, retain) IBOutlet UITextField *nameField;
@property (nonatomic, retain) IBOutlet UITextField *numberField;
@end

ViewController.m

#import "_4_Control_FunViewController.h"

@implementation _4_Control_FunViewController
@synthesize nameField;
@synthesize numberField;


- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}


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

@end

这就是我想要的：

这就是我得到的：

Answer 1

看起来它“应该”有效，但根据你的截图，我会说你没有在Interface Builder中正确连接。

转到Interface Builder并确保它们已连接。如果您在头文件中声明了IBOutlet，则需要将其连接到Interface Builder中的相应UI对象。

您还有一些冗余代码（如下所示）。它们不会引起问题，但它们会加倍，因为你将它们声明为.h文件底部的属性。您可以从标题中删除下面的行，但请确保保留相应的@property声明。

UIWindow *window;
_4_Control_FunViewController *viewController;

UITextField *nameField;
UITextField *numberField;