Question

有两个IBOutlet，即使它们包含在视图控制器文件中，也不会出现在文件所有者中以进行连接。为什么呢？

以下是接口和实现文件的代码。使用Xcode 4.2。

CoinTossViewController.h

#import <UIKit/UIKit.h>

@interface CoinTossViewController : UIViewController {
    UILabel *status;
    UILabel *result;
}

@property (nonatomic, retain)UILabel *status;
@property (nonatomic, retain)UILabel *result;

- (IBAction)callHeads;
- (IBAction)callTails;


@end

ToinCossViewController.m

#import "CoinTossViewController.h"
#import <QuartzCore/QuartzCore.h>

@implementation CoinTossViewController

@synthesize status, result;

- (void)simulateCoinToss:(BOOL)userCalledHeads {
    BOOL coinLandedOnHeads = (arc4random() % 2) == 0;

    result.text = coinLandedOnHeads ? @"Heads" : @"Tails";

    if (coinLandedOnHeads == userCalledHeads)
        status.text = @"Correct!";

    else 
        status.text = @"Wrong!";

    CABasicAnimation *rotation = [CABasicAnimation
                              animationWithKeyPath:@"transform.rotation"];
    rotation.timingFunction = [CAMediaTimingFunction     functionWithName:kCAMediaTimingFunctionEaseOut];
    rotation.fromValue = [NSNumber numberWithFloat:0.0f];
    rotation.toValue = [NSNumber numberWithFloat:720 * M_PI / 180.0f];
    rotation.duration = 2.0f;
    [status.layer addAnimation:rotation forKey:@"rotate"];

    CABasicAnimation *fade = [CABasicAnimation animationWithKeyPath:@"opacity"];
    fade.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
    fade.fromValue = [NSNumber numberWithFloat:0.0f];
    fade.toValue = [NSNumber numberWithFloat:1.0f];
    fade.duration = 3.5f;
    [status.layer addAnimation:fade forKey:@"fade"];
}

 - (IBAction)callHeads
{
     [self simulateCoinToss:YES];
}

- (IBAction)callTails
{
    [self simulateCoinToss:NO];
}

- (void) viewDidUnload
{
    self.status = nil;
    self.result = nil;
}

- (void) dealloc 
{ 
    [status release];
    [result release];
    [super dealloc];
}
@end

Answer 1

您没有在那里定义任何IBOutlets。您想要状态和结果是出口吗？如果是这样，请执行以下操作：

@property (nonatomic, retain) IBOutlet UILabel *status;
@property (nonatomic, retain) IBOutlet UILabel *result;

Answer 2

尝试将标题更改为：

#import <UIKit/UIKit.h>

@interface CoinTossViewController : UIViewController {
    UILabel *status;
    UILabel *result;
}

@property (nonatomic, retain)IBOutlet UILabel *status;
@property (nonatomic, retain)IBOutlet UILabel *result;

- (IBAction)callHeads;
- (IBAction)callTails;


@end

IBOutlets不会出现在Interface Builder中

2 个答案: