iphone - iOS - 删除以编程方式添加的 subview 并在标签中打印日期

Question

我需要一些与 iOS 应用相关的帮助

单击按钮时，我以编程方式添加了一个 DatePicker，现在我无法删除 View ，这是我的代码

我也尝试将日期放在标签 dateLabel 中，但它显示了一些运行时错误，因为它不是字符串格式我尝试了一些其他方法也像 NSDateFormatter 但我没有得到正确的结果

-(IBAction)date:(id)sender{

    UIDatePicker *datePicker=[[UIDatePicker alloc]initWithFrame:CGRectMake(420, 320, 300, 500)];

    [datePicker addTarget:self action:@selector(Pick:) forControlEvents:UIControlEventValueChanged];

    [self.view addSubview:datePicker];

    NSData *date=[datePicker date];
    NSLog(@"%@",date);
    dateLabel.text=date;
}

-(void)Pick:(id)sender{

    [datePicker removeFromSuperview];
}

Answer 1

这样做

-(IBAction)date:(id)sender
{
   datePicker=[[UIDatePicker alloc]initWithFrame:CGRectMake(420, 320, 300, 500)];
   [datePicker addTarget:self action:@selector(Pick:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:datePicker];
}

-(void)Pick:(id)sender
  {
     NSDateFormatter *df = [[NSDateFormatter alloc] init];
    df.dateStyle = kCFDateFormatterShortStyle;
     label.text=[NSString stringWithFormat:@"%@",
                     [df stringFromDate:datePicker.date]];
     [df release];
   [datePicker removeFromSuperview];
    datePicker=nil;
  }