target-action传值

Target-Action传值

实质就是：A页面要给B页面传值,A就提供接口出去,抓A到B内部来,A间接调用自己内部方法(相当于,A把自己内部需 要操作的方法,传到B内来,到B内部进行赋值,这样就不存在訪问不到各自的局部实例变量)

@property (nonatomic,assign)id traget;
@property (nonatomic,assign)SEL action;

[self.traget performSelector:self.action withObject:nil];(是否须要传參数自己定,最多2个)

代码例如以下:

#import "FirstViewController.h"
#import "SecondViewController.h"
#import "UIButton+Create.h"
@interface FirstViewController ()
{
UILabel * _label;
}
@end

@implementation FirstViewController
- (void)dealloc
{
[_label release];
[super dealloc];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];

self.view.backgroundColor = [UIColor redColor];
self.navigationItem.title = @"首页";

_label = [[UILabel alloc]initWithFrame:CGRectMake(50, 80, 200, 30)];
_label.backgroundColor = [UIColor greenColor];

//    _label.text = self.text;
[self.view addSubview:_label];

UIButton * button = [UIButton systemButtonWithFrame:CGRectMake(100, 120, 50, 50) title:@"Push" target:self action:@selector(didClickButtonAction)];
[self.view addSubview:button];

// Do any additional setup after loading the view.
}

- (void)didClickButtonAction
{

SecondViewController * secondVC = [[SecondViewController alloc]init];
secondVC.target = self;
secondVC.action = @selector(didClick:);
[self.navigationController pushViewController:secondVC animated:YES];
[secondVC release];
}

- (void)didClick:(NSString *)text
{
_label.text = text;
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end

#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController

@property (nonatomic,assign)id target;
@property (nonatomic,assign)SEL action;
@end

#import "SecondViewController.h"
#import "FirstViewController.h"
#import "UIButton+Create.h"
@interface SecondViewController ()
{
UITextField * _textField;//创建一个输入框
}
@end
@implementation SecondViewController

- (void)dealloc
{
[_textField release];
[super dealloc];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor orangeColor];
self.navigationItem.title = @"第二页";

_textField = [[UITextField alloc]initWithFrame:CGRectMake(50, 80, 200, 30)];
_textField.borderStyle = UITextBorderStyleRoundedRect;
[self.view addSubview:_textField];

UIButton * button = [UIButton systemButtonWithFrame:CGRectMake(100, 120, 50, 50) title:@"Back" target:self action:@selector(didClickButtonAction)];
[self.view addSubview:button];

// Do any additional setup after loading the view.
}

- (void)didClickButtonAction
{
[_target performSelector:_action withObject:_textField.text];
[self.navigationController popToRootViewControllerAnimated:YES];
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}

@end