Xcode 保存 UIDatepicker 以显示在标签中答案

【问题标题】：Xcode Saving UIDatepicker to be displayed in a labelXcode 保存 UIDatepicker 以显示在标签中
【发布时间】：2011-01-30 04:45:29
【问题描述】：

下面的代码是为了展示我的UIDatepicker：

- (IBAction)showActionSheet:(id)sender {
    NSString *title = UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation) ? @"\n\n\n\n\n\n\n\n\n" : @"\n\n\n\n\n\n\n\n\n\n\n\n" ;
    UIActionSheet *actionSheet = [[UIActionSheet alloc] 
                                  initWithTitle:[NSString stringWithFormat:@"%@%@", title, NSLocalizedString(@"Please Select A Date", @"")]
                                  delegate:self cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:@"I've Made My Choice", nil];
    [actionSheet showInView:self.view];
    UIDatePicker *datePicker = [[[UIDatePicker alloc] init] autorelease];
    datePicker.datePickerMode = UIDatePickerModeDate;
    [actionSheet addSubview:datePicker];
}

一切正常，但我想做的是将用户选择显示到我命名为“label1”的标签中。任何人都可以帮忙吗？谢谢！

更新：

这是更新后的代码：

- (IBAction)showActionSheet:(id)sender {
NSString *title = UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation) ? @"\n\n\n\n\n\n\n\n\n" : @"\n\n\n\n\n\n\n\n\n\n\n\n" ;
UIActionSheet *actionSheet = [[UIActionSheet alloc] 
                              initWithTitle:[NSString stringWithFormat:@"%@%@", title, NSLocalizedString(@"Please Select A Date", @"")]
                              delegate:self cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:@"I've Made My Choice", nil];
[actionSheet showInView:self.view];
UIDatePicker *datePicker = [[[UIDatePicker alloc] init] autorelease];
datePicker.datePickerMode = UIDatePickerModeDate;
[actionSheet addSubview:datePicker];
[datePicker addTarget:self
               action:@selector(updateLabel:)
     forControlEvents:UIControlEventValueChanged];

}

- (void)updateLabel:(id)sender {
NSDateFormatter *df = [[NSDateFormatter alloc] init];
df.dateStyle = NSDateFormatterMediumStyle;
label1.text = [NSString stringWithFormat:@"%@",[df stringFromDate:datePicker.date]];
[df release];


/* the following allows you to choose the date components
 NSCalendar *calendar = [NSCalendar currentCalendar];

 int hour   =    [[calendar components:NSHourCalendarUnit    fromDate:[datePicker date]] hour];
 int minute =    [[calendar components:NSMinuteCalendarUnit  fromDate:[datePicker date]] minute];

 int year   =    [[calendar components:NSYearCalendarUnit    fromDate:[datePicker date]] year];
 int month  =    [[calendar components:NSMonthCalendarUnit   fromDate:[datePicker date]] month];
 int day    =    [[calendar components:NSDayCalendarUnit     fromDate:[datePicker date]] day];
 */

}
那是针对 .m 的，我的 .xib 也有正确绑定的“标签”:) 每当我选择日期时都会得到一个（空）值 :(

【问题讨论】：

标签： iphone uidatepicker uiactionsheet

【解决方案1】：

.h

#import <UIKit/UIKit.h>
@interface YourViewController : UIViewController {
    IBOutlet UILabel *label1;
}
@property (nonatomic, retain) UILabel *label1;
@end

.m

@implementation YourViewController
@synthesize label1;
/*
     All of your code goes here
 */
@end

界面生成器

还将以下内容添加到您的showActionSheet:

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

这应该会从datePicker更新您的标签：

-(void)updateLabel:(id)sender
{
    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    df.dateStyle = NSDateFormatterMediumStyle;
    label1.text = [NSString stringWithFormat:@"%@",[df stringFromDate:datePicker.date]];
    [df release];


    /* the following allows you to choose the date components
    NSCalendar *calendar = [NSCalendar currentCalendar];

    int hour   =    [[calendar components:NSHourCalendarUnit    fromDate:[datePicker date]] hour];
    int minute =    [[calendar components:NSMinuteCalendarUnit  fromDate:[datePicker date]] minute];

    int year   =    [[calendar components:NSYearCalendarUnit    fromDate:[datePicker date]] year];
    int month  =    [[calendar components:NSMonthCalendarUnit   fromDate:[datePicker date]] month];
    int day    =    [[calendar components:NSDayCalendarUnit     fromDate:[datePicker date]] day];
      */
}

【讨论】：

当我添加它时，我得到“datePicker”未声明，但是当我更新我的 .h 文件以具有 NSString *datePicker; ，我收到“在非结构或联合的情况下请求成员‘日期’”
哦，是的，对不起，在你的标题中定义 datePicker，使用@property，然后在你的.m 中，使用@synthesize。然后在您的“showActionSheet”中，删除“UIDatePicker *”。
是的，如果你使用 XIB，那么你需要在 header 中使用 @property 和 IBOutlet / 在 .m 中使用 @synthesize 并在 Interface Builder 中连接所有内容。
当我将 datePicker 连接到标签时，它不会连接。它就像标签不在界面上一样，即使在标题中有 @property 和 IBOutlet 并且在 .m 中有 @synthesize 也是如此。在我的 .h 中：IBOutlet UILabel *label1; IBOutlet UIDatePicker *datePicker;两者都具有适当的 @property(nonatomic, retain)IBOutlet UILabel *label1; @property（非原子，保留）IBOutlet UIDatePicker *datePicker;和 @synthesized 他们都在 .m
datePicker 是 UIDatePicker，所以它自然不会连接到您的 UILabel。您将 label1 连接到 IB 中的 Label，然后将 datePicker 连接到 IB 中的 UIDatePicker

【解决方案2】：

这里我在UITableview 单元格中显示UIDatePicker。

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {   
    // Make a new view, or do what you want here    
    UIDatePicker *pv = [[UIDatePicker alloc] initWithFrame:CGRectMake(0,185,0,0)];    
    [self.view addSubview:pv];    
    return NO;    
}

如果您使用的是UITableView，请使用以下命令来显示UIDatePicker 而不是键盘。

if (0 == indexPath.row) {
    cell.rightTextField.placeholder = @”Date”;
    cell.rightTextField.text = [coAccident strDateTime];
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}

UIDatePicker *datePicker = [[UIDatePicker alloc]initWithFrame:CGRectMake(0, 0, 185, 0)];
[datePicker addTarget:self action:@selector(changeDateInLabel :) forControlEvents:UIControlEventValueChanged];
cell.rightTextField.inputView = datePicker;
} 

- (IBAction)changeDateInLabel:(id)sender {
    UIDatePicker * datePicker = (UIDatePicker*)sender;
    CAccidentVO* coAccident = [m_arrVehicles objectAtIndex:1];
    NSDateFormatter *df = [[NSDateFormatter alloc] init];
    df.dateStyle = NSDateFormatterMediumStyle;   
    [coAccident setStrDateTime:[NSString stringWithFormat:@"%@",[df stringFromDate:datePicker.date]]];  
    [df release];  
    [m_tvVehicleDetails reloadData];
}

【讨论】：