iOS中使用block傳值

用此方法傳值可以替代委託了。具體例子 MainView.h

#import<UIKit/UIKit.h>

@interface MainView : UIViewController

{

   IBOutlet UIButton* btn;

   IBOutlet UILabel* labShow;

}

-(IBAction)push:(id)sender;

@end

MainView.m

 

#import "MainView.h"

#import "SecondView.h"

@implementation MainView

- (id)initWithNibName:(NSString*)nibNameOrNil bundle:(NSBundle*)nibBundleOrNil

{

   self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

   if (self) {

    }

   return self;

}

- (void)didReceiveMemoryWarning

{

   [superdidReceiveMemoryWarning];

}

#pragma mark - View lifecycle

- (void)viewDidLoad

{

   [superviewDidLoad];

}

-(IBAction)push:(id)sender

{

   SecondView *s =[[SecondView alloc] initwithBlock:Block_copy(^(NSString *str){

      NSLog(@"%@",str);

      labShow.text = str;

    })];

   [self.navigationController pushViewController:s  animated:YES];

    [s release];

}

- (void)viewDidUnload

{

   [superviewDidUnload];

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

   return (interfaceOrientation == UIInterfaceOrientationPortrait);

}

@end

Second.h

 

#import<UIKit/UIKit.h>

typedef void (^MyBlock)(NSString*);

@interface SecondView : UIViewController

{

   IBOutlet UITextField*txtView;

   MyBlock my;

}

-(IBAction)back:(id)sender;

-(id)initwithBlock:(MyBlock)str;

@end

Second.m

 

#import "SecondView.h"

@implementation SecondView

-(id)initwithBlock:(MyBlock)str

{

   self = [super init];

   if(self)

   {   

      my =str;

    }

   return self;

}

-(IBAction)back:(id)sender

{

   NSString* s = txtView.text;

   if(my)

    {

      my(s);

    }

   [self.navigationControllerpopViewControllerAnimated:YES];

}

- (void)didReceiveMemoryWarning

{

   [superdidReceiveMemoryWarning];

}

-(void)dealloc{

   Block_release(my);

    [super dealloc];

   

}

#pragma mark - View lifecycle

- (void)viewDidLoad

{

   [superviewDidLoad];

}

- (void)viewDidUnload

{

   [superviewDidUnload];

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

   return (interfaceOrientation == UIInterfaceOrientationPortrait);

}

@end