PopupViewController返回null到ViewController

Question

我想從DatePickerPopupViewController傳遞datepicker.date到我的SensorvViewcontroller，如下所示。但是，它返回給我「null」。我究竟做錯了什麼？我的代碼如下：

#import "DatePopoverViewController.h" 

@interface DatePopoverViewController() 

@end 

@implementation DatePopoverViewController 
@synthesize datePicker; 
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
{ 
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 
    if (self) { 
     // Custom initialization 
    } 
    return self; 
} 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view from its nib. 
    datePicker.date=[NSDate date]; 
} 



@end 

#import "SensorViewController.h" 

@interface SensorViewController() 

@end 
// this represent my button which triggers popupViewController 

-(void)chooseDate 
{ 

    if([popoverController isPopoverVisible]) 
    { 
    [popoverController dismissPopoverAnimated:YES]; 

    } 
    else 
    { 
     CGRect popRect=CGRectMake (900,1,1,1); 
     //CGRect popRect=CGRectMake (tools.frame.origin.x,tools.frame.origin.y,50,50); 
     popoverController.popoverContentSize =CGSizeMake(320,216); 
     [popoverController presentPopoverFromRect:popRect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES]; 
     datepop=[[DatePopoverViewController alloc]init]; 
     NSDate *ali= datepop.datePicker.date; 
     NSLog(@"%@",ali); 
    } 

} 

    @end 

Answer 1

此代碼：

CGRect popRect=CGRectMake (900,1,1,1); 
    //CGRect popRect=CGRectMake (tools.frame.origin.x,tools.frame.origin.y,50,50); 
    popoverController.popoverContentSize =CGSizeMake(320,216); 
    [popoverController presentPopoverFromRect:popRect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES]; 
    datepop=[[DatePopoverViewController alloc]init]; 
    NSDate *ali= datepop.datePicker.date; 
    NSLog(@"%@",ali); 

可能應該更喜歡：

popoverController=[[DatePopoverViewController alloc]init]; 

    CGRect popRect=CGRectMake (900,1,1,1); 
    //CGRect popRect=CGRectMake (tools.frame.origin.x,tools.frame.origin.y,50,50); 
    popoverController.popoverContentSize =CGSizeMake(320,216); 
    [popoverController presentPopoverFromRect:popRect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES]; 

，你應該建立一個委託關係或阻止回調，以便在用戶實際選擇日期時調用方法並調用y OU可以這樣做：

NSDate *ali= popoverController.datePicker.date; 
NSLog(@"%@",ali); 

或者，更好的酥料餅的控制器從所述拾取器獲取的日期，並將其作爲一個參數傳遞給回調方法/塊。

---

類似的信息（類型直列）：

在酥料餅：

typedef void (^CompletionBlock)(); 

@propertty (copy, nonatomic) CompletionBlock completionBlock; 

- (void)dateSelected { 
    self.completion(); 
} 

在源控制器：

self.popoverController.completionBlock = ^{ 
    NSLog(@"%@", self.popoverController.datePicker.date); 
}; 

Answer 2

這下面的代碼工作：

//在標題中

@property (nonatomic,strong) UIDatePicker *datePicker; 

//實施

UIViewController* popoverContent = [[UIViewController alloc] init]; //ViewController 

UIView *popoverView = [[UIView alloc] init]; //view 
popoverView.backgroundColor = [UIColor blackColor]; 

datePicker=[[UIDatePicker alloc]init];//Date picker 
datePicker.frame=CGRectMake(0,44,320, 216); 
datePicker.datePickerMode = UIDatePickerModeDateAndTime; 
[datePicker setMinuteInterval:5]; 
[datePicker setTag:10]; 
[datePicker addTarget:self action:@selector(Result) forControlEvents:UIControlEventValueChanged]; 
[popoverView addSubview:datePicker]; 

popoverContent.view = popoverView; 
popoverController = [[UIPopoverController alloc] initWithContentViewController:popoverContent]; 
popoverController.delegate=self; 
[popoverContent release]; 

[popoverController setPopoverContentSize:CGSizeMake(320, 264) animated:NO]; 
[popoverController presentPopoverFromRect:tempButton.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];//tempButton.frame where you need you can put that frame 

-(void)Result 
{ 

NSLog (@"Pciked Date%@", datePicker.date); 
}