如何使用两个Push Segue在导航控制器中的两个View Controller之间传递数据？

Question

I have two view controllers inside a Navigation Controller. In the first view controller I have two buttons. Both of them call the second view controller using a Push segue, but:

1. I need to know which button sent me in the second view controller. How?
2. In the second view controller I have a UIDatePicker and a Button "Ok": how can I send the chosen date to the first view controller when Ok is pressed? (And how do I receive them?)

EDIT:

I don't know if my problem is clear: now I know how to pass data from the first view controller to the second view controller with prepareForSegue, but what I really need is to pass data (the picked date) from the second view controller to the first, and how can I do it without a prepareForSegue (when Ok is pressed)?

EDIT2:

I made it. It was so simple, guys... I decided to use modal segue:

Firstviewcontroller.h:

+(FirstViewController *)getInstance;

Firstviewcontroller.m:

static FirstViewController *instance =nil;
+(FirstViewController *)getInstance
{
    return instance;
}

and in its ViewDidLoad:

instance = self;

Secondviewcontroller.m, in the OkButton IBAction:

SecondViewController *secondViewController = [SecondViewController getInstance];

//...
//modify what I need to modify in secondviewcontroller
//...

[self dismissModalViewControllerAnimated:YES];

That's it. Thank you all anyway.

Answer 1

Assign Identifier to each segue in storyboard and implement

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Make sure your segue name in storyboard is the same as this line
    if ([[segue identifier] isEqualToString:@"YOUR_SEGUE_NAME_HERE"])
    {
        // Get reference to the destination view controller
        YourViewController *vc = [segue destinationViewController];
        [vc setDelegate:self];
        // Pass any objects to the view controller here, like...
        [vc setMyObjectHere:object];
    }
}  

For more info about How to use storyboard and pass value check this article or this discussion on stackoverflow

for the second question you can use delegate pattern IN SecondViewController.h

@protocol SomethingDelegate <NSObject>
- (void)dateChanged:(NSString *)dateStr; //you can use NSDate as well

@end
@interface ViewController2 : UIViewController

@property(weak) id<SomethingDelegate> delegate;

@end 

in .m file

-(void) OkClicked{

    [_delegate dateChanged:@"YOUR_DATE_VALUE"];
}

In FirstViewController.h

#import "SecondViewController.h"
@interface FirstViewController : UIViewController<SomethingDelegate>

in .m

  -(void)dateChanged:(NSString *)dateStr{

        // do whatever you need with dateStr
//also i made some change in prepareForSegue method
    }

Note:- take care your naming convenes for VC

Answer 2

• just pass the button id to the second viewcontrol.
• use delegates to sent the data from second viewcontroller back to first view controller

regards

Johan