属性传值 将A页面所拥有的信息通过属性传递到B页面使用
B页面定义了一个naviTitle属性，在A页面中直接通过属性赋值将A页面中的值传到B页面。
#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface RootViewController :UIViewController<ChangeDelegate>
{
UITextField *tf;
}
@end
A RootViewController.m页面实现文件
#import "RootViewController.h"
#import "DetailViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
//核心代码
-(void)loadView
{
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(0, 0, 100, 30);
[btn setTitle:@"Push" forState:0];
[btn addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];
}
-(void)pushAction:(id)sender
{
tf = (UITextField *)[self.viewviewWithTag:1000];
//导航push到下一个页面
//pushViewController 入栈引用计数+1，且控制权归系统
DetailViewController *detailViewController = [[DetailViewControlleralloc]init];
//属性传值，直接属性赋值
detailViewController.naviTitle =tf.text;
//导航push到下一个页面
[self.navigationControllerpushViewController:detailViewController animated:YES];
[detailViewControllerrelease];
}
B页面DetailViewController.h文件
#import <UIKit/UIKit.h>
@interface DetailViewController :UIViewController
{
UITextField *textField;
NSString *_naviTitle;
}
@property(nonatomic,retain)NSString *naviTitle;
@end
B页面.m实现文件
#import "DetailViewController.h"
@interface DetailViewController ()
@end
@implementation DetailViewController
@synthesize naviTitle =_naviTitle;
-(void)loadView
{
self.view = [[[UIViewalloc]initWithFrame:CGRectMake(0,0, 320,480)]autorelease];
self.title = self.naviTitle ;
}
代理传值
A页面push到B页面，如果B页面的信息想回传（回调）到A页面，用用代理传值，其中B定义协议和声明代理，A确认并实现代理，A作为B的代理
A页面RootViewController.h文件
#import <UIKit/UIKit.h>
#import "DetailViewController.h"
@interface RootViewController : UIViewController<ChangeDelegate>
{
UITextField *tf;
}
@end
A页面RootViewController.m实现文件
#import "RootViewController.h"
#import "DetailViewController.h"
@interface RootViewController ()
@end
@implementation RootViewController
//核心代码
-(void)loadView
{
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(0, 0, 100, 30);
[btn setTitle:@"Push" forState:0];
//A页面push到B页面
[btn addTarget:self action:@selector(pushAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];
}
-(void)pushAction:(id)sender
{
tf = (UITextField *)[self.view viewWithTag:1000];
//导航push到下一个页面
//pushViewController 入栈引用计数+1，且控制权归系统
DetailViewController *detailViewController = [[DetailViewController alloc]init];
//代理传值
detailViewController.delegate =self;//让其自身作为代理人
//导航push到下一个页面
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
//实现代理方法
-(void)changeTitle:(NSString *)aStr
{
tf = (UITextField *)[self.view viewWithTag:1000];
tf.text = aStr;//将从B页面传入的参数赋给A页面中的TextField
tf.text = aStr;
}
B页面DetailViewController.m文件
#import <UIKit/UIKit.h>
@interface DetailViewController : UIViewController
{
UITextField *textField;
//定义代理
id<ChangeDelegate>_delegate;
}
@property(nonatomic,assign)id<ChangeDelegate> delegate;
@end
//定义协议
@protocol ChangeDelegate <NSObject>
-(void)changeTitle:(NSString *)aStr;//协议方法
@end
B页面DetailViewController.h实现文件
#import "DetailViewController.h"
@interface DetailViewController ()
@end
@implementation DetailViewController
-(void)loadView
{
self.view = [[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)]autorelease];
UIBarButtonItem *doneItem = [[UIBarButtonItemalloc]initWithBarButtonSystemItem:UIBarButtonSystemItemDonetarget:selfaction:@selector(doneAction:)];
self.navigationItem.rightBarButtonItem = doneItem;
[doneItemrelease];
}
//pop回前一个页面
-(void)doneAction:(id)sender
{
if (self.delegate && [self.delegaterespondsToSelector:@selector(changeTitle:)])//若代理存在且响应了changeTitle这个方法
{
//[self.delegate changeTitle:textField.text];
[self.delegatechangeTitle:textField.text];//将textField.text参数传给changeTitle方法 让代理，也就是A页面去实现这个方法
NSLog(@"%@",self.navigationController.viewControllers);
[self.navigationControllerpopViewControllerAnimated:YES];
}
}
Block
几种形式的Block
//无返回值
void (^block1) (void); block1 = ^{ NSLog(@"bock demo"); }; block1(); //int返回类型 int (^block2) (void); block2 = ^(void) { int a = 1 ,b =1; int c = a+b; return c; }; //有返回 有参数 int (^block3)(int, int)= ^(int a, int b) { int c = a +b; return c; }; NSLog(@"bock=%d",block3(1,2)); //有返回值，有参数并且可以修改block之外变量的block static int sum = 10;// __blcik and static关键字 或者 _block int sum = 10 int (^block4) (int) =^(int a) { sum=11; int c = sum+a; //此时sum就是可以修改的了，若没加static或_block关键字则不能修改block之外变量 return c; }; NSLog(@"block4= %d",block4(4));
Block传值
例如A(Ablock)页面的值传道B(Bblock)页面
在A页面中ABlock.h
@interface Ablock : UIViewController<UITableViewDelegate,UITableViewDataSource>
{ UITableView *_tableview; UILabel *labe; UIImageView *imagevies;}@end
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{ [_tableview deselectRowAtIndexPath:indexPath animated:YES]; Bblcok *bblock = [[Bblcok alloc] initwithBlock:Block_copy(^(NSString *aBlock){ labe.text = aBlock; NSLog(@"%@",aBlock); })]; bblock.imgeviews = imagevies.image; bblock.String = labe.text; [self.navigationController pushViewController:bblock animated:YES]; [bblock release];}
在A页面中Bblock.h
#import <UIKit/UIKit.h>
typedef void (^MyBlock) (NSString *);@interface Bblcok : UIViewController{ UIImageView *image; UITextField *aField; UIButton *aButt; NSString *_String; id _imgeviews; MyBlock myBlock;}@property(nonatomic,copy)MyBlock myBlock; @property(nonatomic,retain) id imgeviews;@property(nonatomic,retain) NSString *String;-(id)initwithBlock:(MyBlock)aBlcok;@end
//
// Bblcok.m// Blcok//// Created by zhu on 13-8-12.// Copyright (c) 2013年 Zhu Ji Fan. All rights reserved.//#import "Bblcok.h"@interface Bblcok ()@end@implementation Bblcok@synthesize imgeviews = _imgeviews , String = _String;@synthesize myBlock = _myBlock;-(id)initwithBlock:(MyBlock)aBlcok{ if (self = [super init]) { self.myBlock = aBlcok; } return self;}-(void) dealloc{ [super dealloc];}-(void) loadView{ UIControl *cont = [[UIControl alloc] initWithFrame:CGRectMake(0, 0, 320, 568-44)]; [cont addTarget:self action:@selector(Clcik) forControlEvents:UIControlEventTouchUpInside]; self.view = cont; aField = [[UITextField alloc] initWithFrame:CGRectMake(60, 10, 160, 30)]; aField.borderStyle = UITextBorderStyleLine; aField.placeholder = self.String; [self.view addSubview:aField]; aButt = [UIButton buttonWithType:UIButtonTypeRoundedRect]; aButt.frame = CGRectMake(60, 50, 70, 30); [aButt setTitle:@"修改" forState:0]; [aButt addTarget:self action:@selector(aButtClcik:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:aButt]; image = [[UIImageView alloc] initWithFrame:CGRectMake(60, 100, 210, 260)]; image.backgroundColor = [UIColor blueColor]; image.image = self.imgeviews; [self.view addSubview:image]; [image release];}-(IBAction)aButtClcik:(id)sender{ NSString *sting = aField.text; myBlock(sting); [self.navigationController popToRootViewControllerAnimated:YES];}-(void)Clcik{ [aField resignFirstResponder];}- (void)viewDidLoad{ [super viewDidLoad]; // Do any additional setup after loading the view.}- (void)didReceiveMemoryWarning{ [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated.}@end