1、定义协议

UIViewPassValueDelegate.h

1 #import 
     
      2 3 @protocol UIViewPassValueDelegate 
      
       4 -(void)passValue:(NSString *)value1;5 @end
      
     

2、A视图定义

1 #import "UIViewPassValueDelegate.h" 2  3 @interface AViewController : UIViewController
     
       4  5 -(IBAction)buttonClick:(id)sender; 6  7 -(void)passValue:(NSString *)value1{ 8     NSLog(@"A get value is %@",value1); 9 }10 11 -(IBAction)buttonClick:(id)sender{12     BViewController *b = [[BViewController alloc] init];13     b.delegate = self;  // 将A作为一个变量传给B，这样在B中对delegate的任何操作其实就是对A的操作。14     [self presentViewController:b animated:YES completion:nil];15 }
     

3、B视图定义

1 #import "UIViewPassValueDelegate.h" 2  3 NSObject
     
       *delegate; 4 @property (nonatomic,retain) NSObject
      
        *delegate; 5 - (IBAction)buttonClick:(id)sender; 6  7 @synthesize delegate; 8 -(IBAction)buttonClick:(id)sender{ 9     [delegate passValue:@"ddd"];10     NSLog(@"B text = ddd");11     [self dismissViewControllerAnimated:YES completion:nil];12 }
      
     

这样我点击B视图的按钮时就可以将值传给A视图了。