Question

我是Objective-C的新手。我想在警报视图中显示当前日期和时间。

- (IBAction)postButtonPressed:(UIButton *)sender  {

    NSString *formatString = [NSDateFormatter dateFormatFromTemplate:@"MMM d, yyyy h:mm" options:0 locale:[NSLocale currentLocale]];

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:formatString];

    NSString *todayString = [dateFormatter stringFromDate:[NSDate date]];

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Message Posted" message:@"Your Message is posted on: @todayString" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
    [alert show];
      }

Answer 1

您的警报消息字符串需要重做。试试这个：

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Message Posted" 
message:[NSString stringWithFormat:@"Your Message is posted on: %@", todayString] 
delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];

Answer 2

您可以使用NSString或stringWithFormat:联接stringWithString:，还有其他可用的附加功能，see doc

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Message Posted" message:[NSString stringWithFormat:@"Your Message is posted on: %@",todayString] delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[alert show];
[alert release]; //don't forget to release UIAlertView object if you don't using ARC

Answer 3

尝试

NSString *str = [NSString stringWithFormat:@"Your Message is posted on: %@", todayString];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Message Posted" message:str delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[alert show];

带有时间戳的UIAlertView

3 个答案: