不完整的实现

Question

我在我的实现页面上收到了一个不完整的实现警告，我已经将其注释掉了：

#import "BIDDatePickerViewController.h"

@implementation BIDDatePickerViewController   // Incomplete implementation

@synthesize datePicker;

- (IBAction)buttonPressed:(id)sender
{
    NSDate *selected = [datePicker date];
    NSString *message = [[NSString alloc] initWithFormat:@"The date and time you selected is:%@", selected];
    UIAlertView *alert = [[UIAlertView alloc]
                          initWithTitle:@"Date and Time Selected" 
                          message:message 
                          delegate:nil 
                          cancelButtonTitle:@"Yes I did" 
                          otherButtonTitles:nil];
    [alert show];
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    NSDate *now = [NSDate date];
    [datePicker setDate:now animated:NO];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    self.datePicker = nil;

}
@end

此外，消息的自定义部分，显示所选的日期和时间没有正确显示。为什么？

以下是接口文件：

#import <UIKit/UIKit.h>

@interface BIDDatePickerViewController : UIViewController

@property (strong, nonatomic) IBOutlet UIDatePicker *datePicker;

-(IBAction)buttonPressed;

@end

Answer 1

收到警告的原因是您在定义方法-(IBAction)buttonPressed;的同时实现了方法- (IBAction)buttonPressed:(id)sender。请注意，接口上缺少参数。

Answer 2

在.h文件中有- (IBAction)buttonPressed;，在.m文件中有- (IBAction)buttonPressed:(id)sender。您的.m文件中应该包含- (IBAction)buttonPressed;