ios之两个view传值

delegate：
demo使用场景，我有A，B两个controller，A是root，跳转到B，B的数据输入完返回A且携带数据显示到A。

A.h

#import <UIKit/UIKit.h>
#import "SencondViewController.h"


@interface FirstViewController : UIViewController<ResultDelegate>

@property (strong, nonatomic) IBOutlet UIButton *delegateBtn;

@property (strong, nonatomic) IBOutlet UITextField *result_name;

@property (strong, nonatomic) IBOutlet UITextField *result_pass;

@property SencondViewController *second;

- (IBAction)delegateAction:(id)sender;

- (IBAction)observeAction:(id)sender;

@end

A.m

#import "FirstViewController.h"
#import "SencondViewController.h"

@interface FirstViewController ()

@end

@implementation FirstViewController

@synthesize result_name;
@synthesize result_pass;


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

}

- (IBAction)delegateAction:(id)sender {
    self.second = [[SencondViewController alloc]init];
    self.second.deleage = self;
    [self.navigationController pushViewController:self.second animated:true];
}

-(void)result:(NSString *)name pre:(NSString *)pass{
    result_name.text = name;
    result_pass.text = pass;
}

@end

====================================================

B.h

#import <UIKit/UIKit.h>

@protocol ResultDelegate
@required
-(void)result:(NSString *)name pre:(NSString *)pass;
@end

@interface SencondViewController : UIViewController

@property (strong, nonatomic) IBOutlet UITextField *_name;

@property (strong, nonatomic) IBOutlet UITextField *_password;

- (IBAction)save:(id)sender;

@property (retain, nonatomic) id<ResultDelegate> deleage;

@end

B.m

#import "SencondViewController.h"

@interface SencondViewController ()

@end

@implementation SencondViewController

@synthesize _name;
@synthesize _password;

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (IBAction)save:(id)sender {
    
    NSString *txtName = [self._name text];
    
    NSString *txtPass = [self._password text];
    
    [self.deleage result:txtName pre:txtPass];
    
    [self.navigationController popViewControllerAnimated:true];
}

@end