ios实现页面间传值

1.简单的传值，使用类、属性

  在viewcontrol2中声明一个接受传值的变量(需要在.h中声明)。

使用：在跳转时调用----代码如下：

 TwoActivity *t=[[TwoActivity
alloc]init];
    t.s=@"sb";
    self.delegate=t;

    [self.navigationController
pushViewController:t animated:YES];
2.使用代理传值
 在viewcontrol1中声明协议，并在属性中持有改协议，在m中实现该协议，在跳转时为协议注明代理为跳转到的viewcontrol，后调用协议中方法，即可实现传值，viewcontrol2也必须实现该协议，代码如下：

viewcontrol1.h:

#import <UIKit/UIKit.h>
@protocol MyDelegate

-(void)sendValue:(NSString*)values;

@end
@interface ViewController :
UIViewController

@end
============

#viewcontrol1.m

#import "ViewController.h"
#import "TwoActivity.h"

@interface ViewController ()
@property (retain,nonatomic)
id <MyDelegate> delegate;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super
viewDidLoad];
   UIView *back= [[UIView
alloc]initWithFrame:CGRectMake(0,
0, [[UIScreen
mainScreen] bounds].size.width, [[UIScreen
mainScreen] bounds].size.height)];
    back.backgroundColor=[UIColor
blueColor];
    [self.view
addSubview:back];
    // Do any additional setup after loading the view, typically from a nib.
    TwoActivity *t=[[TwoActivity
alloc]init];
    self.delegate=t;
    [self.delegate
sendValue:@"test"];
    [self.navigationController
pushViewController:t animated:YES];
}
====================
viewcontrol2.m

#import "TwoActivity.h"
#import "ViewController.h"

@interface TwoActivity ()<MyDelegate>

@end

@implementation TwoActivity

- (void)viewDidLoad {
    [super
viewDidLoad];
    NSLog(@"%@",self.s);

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

- (void)didReceiveMemoryWarning {
    [super
didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
-(void)sendValue:(NSString *)values{
//这里方法的参数就是传递过来的数据
    NSLog(@"%@",values);
}