objective-c - 此类与键错误的键值编码不兼容

Question

我的问题是当我构建应用程序时出现此错误

Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<FirstViewController 0x717ea40> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key hourTimeOutOfBraceChanged.'

这是我的头文件

#import <UIKit/UIKit.h>
#import "Brace.h"

@interface FirstViewController : UIViewController
@property (weak, nonatomic) IBOutlet UILabel *timeOutOfBraceLabel;
@property (weak, nonatomic) IBOutlet UILabel *weeklyGoalLabel;
@property (strong, nonatomic) Brace *brace;

- (IBAction)minuteTimeOutOfBraceChanged:(id)sender;
//- (IBAction)hourTimeOutOfBraceChanged:(id)sender;

- (void)updateUI;
- (void)retreiveData;
- (void)checkTime;

@end

这是我的 m 文件:

#import "FirstViewController.h"

@interface FirstViewController ()

@end

@implementation FirstViewController

- (Brace *)brace {
if (!_brace) {
    _brace = [[Brace alloc] init];
}
return _brace;
}

- (void)viewDidLoad
{
[self retreiveData];
[self updateUI];
[super viewDidLoad];
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

- (void)updateUI {
// Update timeOutOfBrace
NSString *timeOutOfBraceString = [[NSString alloc] init];
NSString *timeOutOfBraceHoursString = [[NSString alloc] init];
NSString *timeOutOfBraceMinutesString = [[NSString alloc] init];
NSLog(@"%d", self.brace.timeOutOfBrace.todayHours);
timeOutOfBraceHoursString = [NSString stringWithFormat:@"%d", self.brace.timeOutOfBrace.todayHours];
if (self.brace.timeOutOfBrace.todayMinutes < 10) {
    timeOutOfBraceMinutesString = [NSString stringWithFormat:@"0%d", self.brace.timeOutOfBrace.todayMinutes];
}
else {
    timeOutOfBraceMinutesString = [NSString stringWithFormat:@"%d", self.brace.timeOutOfBrace.todayMinutes];
}
timeOutOfBraceString = [NSString stringWithFormat:@"%@:%@", timeOutOfBraceHoursString, timeOutOfBraceMinutesString];
self.timeOutOfBraceLabel.text = timeOutOfBraceString;

// Update weeklyGoal
NSString *weeklyGoalString = [[NSString alloc] init];
NSString *totalHoursThisWeekString = [[NSString alloc] init];
int totalHoursThisWeekDecimal = self.brace.timeOutOfBrace.overallHours + round(self.brace.timeOutOfBrace.overallMinutes/60);
totalHoursThisWeekString = [NSString stringWithFormat:@"%d", totalHoursThisWeekDecimal];
weeklyGoalString = [NSString stringWithFormat:@"%d", self.brace.timeOutOfBrace.goalForWeek];
self.weeklyGoalLabel.text = [NSString stringWithFormat:@"%@/%@", totalHoursThisWeekString, weeklyGoalString];
}

- (void)retreiveData {
self.brace.timeOutOfBrace.todayHours = 4;
self.brace.timeOutOfBrace.todayMinutes = 0;
self.brace.timeOutOfBrace.overallHours = 12;
self.brace.timeOutOfBrace.overallMinutes = 0;
self.brace.timeOutOfBrace.goalForWeek = 28;
}

- (IBAction)minuteTimeOutOfBraceChanged:(id)sender {
if ([[sender currentTitle] isEqualToString:@"+"]) {
    self.brace.timeOutOfBrace.todayMinutes = [self.brace timeOutOfBraceChanged:YES
                                                                              :@"minutes"
                                                                              :self.brace.timeOutOfBrace.todayMinutes];
}
else {
    self.brace.timeOutOfBrace.todayMinutes = [self.brace timeOutOfBraceChanged:NO
                                                                              :@"minutes"
                                                                              :self.brace.timeOutOfBrace.todayMinutes];
}
[self checkTime];
}

- (IBAction)hourTimeOutOfBraceChanged:(id)sender {
if ([[sender currentTitle] isEqualToString:@"+"]) {
    self.brace.timeOutOfBrace.todayMinutes = [self.brace timeOutOfBraceChanged:YES
                                                                              :@"hours"
                                                                              :self.brace.timeOutOfBrace.todayHours];
}
else {
    self.brace.timeOutOfBrace.todayMinutes = [self.brace timeOutOfBraceChanged:NO
                                                                              :@"hours"
                                                                              :self.brace.timeOutOfBrace.todayHours];
}
[self checkTime];
} 

- (void)checkTime {
if (self.brace.timeOutOfBrace.todayMinutes < 0) {
    self.brace.timeOutOfBrace.todayMinutes = 45;
    self.brace.timeOutOfBrace.todayHours -= 1;
    }
    if (self.brace.timeOutOfBrace.todayMinutes > 45) {
        self.brace.timeOutOfBrace.todayMinutes = 0;
        self.brace.timeOutOfBrace.todayHours += 1;
    }
}

@end

老实说，我已经尝试了我所知道的所有可能的解决方案。我检查了与我的 View 的所有连接，它们都很好。先感谢您。

Answer 1

如果您在接口(interface)生成器中为该缺失键的某些 UILabel 实例提供了一个键，然后将其删除，则会导致该错误。 Ctrl 单击 View Controller 的文件所有者并从那里删除缺少的键。