NSNumber 在 NSDictionary 初始化中使用时变为 nil

Question

我有以下代码块：

NSNumber* dayNsNumber = [[NSNumber alloc] initWithInt:dayNumber+1];
NSLog(@"dayNsNumber: %d", [dayNsNumber intValue]);

if(boolVar){

    UIAlertView* success = [[UIAlertView alloc] initWithTitle:@"Title" message:[NSString stringWithFormat:@"Day %d!", dayNumber+1] delegate:self cancelButtonTitle:nil otherButtonTitles:@"Star", nil];
    [success show];
    NSLog(@"dayNsNumber: %d", [dayNsNumber intValue]);
    NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
            dayNsNumber, "Day Number",
            [self getCurrentLocalDate], @"Date",
            [self getCurrentLocalTime], @"Time",
         nil];
}

发生的情况是，当我运行代码时，它会在

params

NSDictionary

初始化时挂起，并表示

dayNsNumber

是

nil

。

Xcode 显示线程 1：EXC_BAD_ACCESS (code=1)。

我该如何解决这个问题？我想将

dayNsNumber

添加到我的

params

字典中。

此外，还有

getCurrentLocalDate

和

getCurrentLocalTime

：

-(NSString*)getCurrentLocalDate;{ 
    NSString *formatString = [NSDateFormatter dateFormatFromTemplate:@"dd-MM-yyyy" options:0 locale:[NSLocale currentLocale]];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:formatString];

    NSString *todayString = [dateFormatter stringFromDate:[NSDate date]];
    NSLog(@"todayString: \"%@\"", todayString);
    return todayString;

}

-(NSString*)getCurrentLocalTime;{
    NSString *formatString = [NSDateFormatter dateFormatFromTemplate:@"HH:mm:ss zzz" options:0 locale:[NSLocale currentLocale]];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:formatString];

    NSString *timeString = [dateFormatter stringFromDate:[NSDate date]];
    NSLog(@"timeString: \"%@\"", timeString);
    return timeString;
}

Answer 1

问题出在钥匙上：

"Day Number"

应该是

@"Day Number"

。

另请注意，您现在可以对数字、数组和字典使用新语法。比如这个

NSNumber* dayNsNumber = [[NSNumber alloc] initWithInt:dayNumber+1];

可以这样重写：

NSNumber* dayNsNumber = @(dayNumber+1);

字典初始化可以这样完成：

NSDictionary *params = @{
    @"Day Number" :   dayNsNumber
,   @"Date"       : [self getCurrentLocalDate]
,   @"Time"       : [self getCurrentLocalTime]
};

Answer 2

试试这个

NSDictionary *params = [[NSDictionary alloc]init];
[params setValue:[daysNumber stringValue] forKey:@"Day Number"];