iOS 属性传值 Block传值 两个ViewController之间的

属性传值 就是将A页面的数据传到B页面上，下面就是将FirstViewController的TextField的内容传递到SecondViewController页面的导航栏标题和控制台输出上

#import <UIKit/UIKit.h>

@interface FirstViewController :UIViewController
{

UITextField *tf;
}

@end

#import "FirstViewController.h"

#import "SecondViewController.h"//要将数据传到哪一个页面(ViewController)就引用那个头文件

- (void)viewDidLoad
{

[superviewDidLoad];

//定义一个按钮

UIButton* button = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];

button.frame=CGRectMake(100,100,100,100);

button.backgroundColor= [UIColorredColor];

[button addTarget:selfaction:@selector(doButton)forControlEvents:UIControlEventTouchUpInside];

[self.viewaddSubview:button];

tf = [[UITextFieldalloc]initWithFrame:CGRectMake(10,300,100,40)];

tf.tintColor = [UIColororangeColor];

tf.backgroundColor = [UIColorgrayColor];
tf.tag =1000;
[self.viewaddSubview:tf];
}
-(void)doButton{

tf = (UITextField *)[self.viewviewWithTag:1000];

//push入栈引用计数+1，且控制权归系统

SecondViewController * seV =[[SecondViewControlleralloc]init];//将其实例化，否则找不到相应的属性

//直接属性传值
seV.naviTitle =tf.text;

seV.str =@"传值成功";//属性(赋值)所要传的值要写在推出下一个窗口前面

[self.navigationControllerpushViewController:seVanimated:YES];

}

@end

#import <UIKit/UIKit.h>

@interface SecondViewController :UIViewController

@property(nonatomic,strong)NSString * str;

@property (nonatomic,retain)NSString *naviTitle;

@end

#import "SecondViewController.h"

@interface
SecondViewController ()

@end

@implementation SecondViewController
@synthesize naviTitle =_naviTitle;

- (void)viewDidLoad
{

[superviewDidLoad];

// Do any additional setup after loading the view.

self.view = [[UIViewalloc]initWithFrame:CGRectMake(0,0,320,480)];
self.title =self.naviTitle;//只是为了显示第一页面传过来的内容将其显示到导航标题上
}

-(void)viewWillAppear:(BOOL)animated{

NSLog(@"%@",self.str);

NSLog(@"11---%@",self.naviTitle);

}

@end

Block传值

#import <UIKit/UIKit.h>

@interface FirstViewController :UIViewController
{

UITextField *tf;
}

@property (nonatomic,retain)UILabel *label;

@end

#import "FirstViewController.h"

#import "SecondViewController.h"

@implementation FirstViewController

- (void)viewDidLoad
{

[superviewDidLoad];

//定义一个按钮

UIButton* button = [UIButtonbuttonWithType:UIButtonTypeRoundedRect];

button.frame=CGRectMake(100,100,100,100);

button.backgroundColor= [UIColorredColor];

[button addTarget:selfaction:@selector(doButton)forControlEvents:UIControlEventTouchUpInside];

[self.viewaddSubview:button];

//定义一个显示控件

self.label = [[UILabelalloc]initWithFrame:CGRectMake(0,400,
100,
40)];

self.label.backgroundColor = [UIColorgreenColor];

self.label.text
= nil;//为了显示第二个视图控制器传过来的字符串

[self.viewaddSubview:self.label];

}
-(void)doButton{

tf = (UITextField *)[self.viewviewWithTag:1000];

//push入栈引用计数+1，且控制权归系统

SecondViewController * seV =[[SecondViewControlleralloc]init];//相对应的将其实例化，否则找不到相应的属性

//回调方法将输入框中的数据
传输过来
[seVreturnText:^(NSString *showText) {
self.label.text = showText;
}];

[self.navigationControllerpushViewController:seV
animated:YES];

}

@end

#import <UIKit/UIKit.h>
typedefvoid (^ReturnTextBlock)(NSString *showText);//重新定义了一个名字
@interface SecondViewController :UIViewController

@property (nonatomic,retain)UITextField *tf;

@property (nonatomic,copy)
ReturnTextBlock returnTextBlock;//定义的一个Block属性
- (void)returnText:(ReturnTextBlock)block;

@end

#import "SecondViewController.h"

- (void)viewDidLoad
{

[superviewDidLoad];

//定义一个输入框 将文字传给第一个界面，并且显示在UILabel上

self.tf = [[UITextFieldalloc]initWithFrame:CGRectMake(10,300,
100,
40)];

self.tf.tintColor = [UIColororangeColor];

self.tf.backgroundColor = [UIColorgrayColor];
[self.viewaddSubview:self.tf];

}

//在第一个界面传进来一个Block语句块的函数

//把传进来的Block语句块保存到本类的实例变量returnTextBlock（.h中定义的属性）中，然后寻找一个时机调用
-(void)returnText:(ReturnTextBlock)block{

self.returnTextBlock = block;
}

//而这个时机就是当视图将要消失的时候，需要重写：
-(void)viewWillDisappear:(BOOL)animated{

if (self.returnTextBlock !=nil)
{

self.returnTextBlock(self.tf.text);

NSLog(@"self.tf.text %@",self.tf.text);
}
}

@end