代理和block反向传值

代理传值：

//  SendViewController.h
#import <UIKit/UIKit.h>
@protocol SendInFor <NSObject>
-(void)sendInForIdea:(NSString*)text;
@end
@protocol SendInForTwo <NSObject>
-(void)sender:(NSString*)text;
@end

@interface SendViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>
@property(nonatomic,retain)id <SendInFor> delegate;
@property(nonatomic,retain)id <SendInForTwo> delegateB;
@property(nonatomic,retain)NSIndexPath*indexPath;

@e代理

代理方法

#import "SendViewController.h"

//代理传值
@interface SendViewController ()
{
    UITableView*table;
    NSMutableArray*data;
}
@end

@implementation SendViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    data=[[NSMutableArray alloc]init];
    table=[[UITableView alloc]initWithFrame:self.view.frame style:UITableViewStylePlain];
    table.delegate=self;
    table.dataSource=self;
    [self.view addSubview:table];
    for (int i=0; i<20; i++) {

        NSString*string=[[NSString alloc]initWithFormat:@"数据%d",i];
        [data addObject:string];
    }
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [data count];
}

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{

    return 60;
}

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *str=@"str";
    UITableViewCell*cell=[tableView dequeueReusableCellWithIdentifier:str];
    if (cell==nil) {
        cell =[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:str];
    }
//    cell.selectedBackgroundView = [[UIView alloc] initWithFrame:cell.frame];
    UIImageView *norImage=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 50, 50)];
    [norImage setImage:[UIImage imageNamed:@"image"]];

    cell.textLabel.text=[data objectAtIndex:indexPath.row];
    //点击单元格 变换背景图片
    if ([_indexPath isEqual: indexPath]) {

        cell.accessoryType = UITableViewCellAccessoryCheckmark;
        cell.backgroundColor=[UIColor redColor];
        cell.accessoryView=norImage ;

       /* 可以自定义图片  按钮 文本
        cell.accessoryType=btn;
        cell.accessoryType=label;
         */
    }
        else{
        cell.accessoryType = UITableViewCellAccessoryNone;
        cell.backgroundColor=[UIColor whiteColor];
        cell.accessoryView=nil ;
    }
    return cell;
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([self.delegate respondsToSelector:@selector(sendInForIdea:)]) {

        _indexPath = indexPath;
        [self.delegate sendInForIdea:[data objectAtIndex:indexPath.row]];
        [table reloadData];

//      cell.imageView.image=[UIImage imageNamed:@"2"];
        //延迟操作     延迟跳转时间
       [self performSelector:@selector(pressBtn) withObject:nil afterDelay:3];

    //点击获取的 cell  cell变色
//    UITableViewCell *cell = [table cellForRowAtIndexPath:indexPath];
//    cell.backgroundColor=[UIColor cyanColor];
    }
}
-(void)pressBtn
{

 [self.navigationController popViewControllerAnimated:YES];

}

具体方法

block反向传值：

//  FirstViewController.h

#import <UIKit/UIKit.h>
 //直接回车,第一个参数是返回值类型，第二个为重定义的block名称，第三个为要传参数类型和参数名；然后需要定义重定义block类型的属性，并且实现参数为该重定义类型block的方法。
//typedef <#existing#> <#new#>;
//回调不加断点不容易找出错误
typedef void (^BlockColor)(UIColor *color);
typedef void (^BlockTitle)(NSString *title);

@interface FirstViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>
//block设置为属性，修饰符用copy，即使使用strong，编译器也会将strong处理成copy
@property(nonatomic,copy)BlockColor color;
@property(nonatomic,copy)BlockTitle Title;

@endblock方法

block方法

//  FirstViewController.m

#import "FirstViewController.h"
#import "TableViewCell.h"

//block 反向传值
@interface FirstViewController ()
{
    UITableView *table;
    NSMutableArray *data;
    NSMutableArray *arr;
}
@end

@implementation FirstViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    arr =[[NSMutableArray alloc]init];
    for (int i=0; i<20; i++) {
        NSString * str=[[NSString alloc]initWithFormat:@"数据%d",i];
        [arr addObject:str];
    }

    table=[[UITableView alloc]initWithFrame:self.view.frame style:UITableViewStylePlain];
    table.dataSource=self;
    table.delegate=self;
    [self.view addSubview:table];

}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [arr count];

}

-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{
    TableViewCell *customCell = (TableViewCell *)cell;
    [UIView animateWithDuration:2 animations:^{
        customCell.image.alpha = 1.0f;
    }];
}
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

    TableViewCell *cell=[[[NSBundle mainBundle]loadNibNamed:@"TableViewCell" owner:self options:nil] lastObject];
    cell.Title.text=[arr objectAtIndex:indexPath.row];

    //xib 中button不要设置点击事件   这样可以在cell里面调取按钮（点击单元格的按钮可以跳转）
    cell.button.tag=indexPath.row;
    [cell.button addTarget:self action:@selector(clickAction:) forControlEvents:UIControlEventTouchUpInside];
    cell.image.image =[UIImage imageNamed:@"2"];
    cell.image.alpha =0.2f;
    return cell;

}

- (void)clickAction:(UIButton *)sender
{
    NSInteger tag=sender.tag;
    NSLog(@"block 传值");
   // __weak typeof(self) weakSelf=self;
    if (_Title) {
        _Title([arr objectAtIndex:tag]);
    }
    if (_color) {
        _color([UIColor redColor]);
    }
    [self.navigationController popToRootViewControllerAnimated:YES];
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSLog(@"hello world");

   TableViewCell *cell = [table cellForRowAtIndexPath:indexPath];
    NSString *string = arr[indexPath.row];
    NSLog(@"string=%@",string);
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 70;
}

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

具体方法

调用：

//  RootViewController.h
#import <UIKit/UIKit.h>
#import "SendViewController.h"
@interface RootViewController : UIViewController<SendInFor>

#import "RootViewController.h"
#import "FirstViewController.h"
#import "SendViewController.h"
@interface RootViewController ()
{
    FirstViewController *first;
    SendViewController *send;
    UIButton *btn;
    UIButton *btn1;
}
@end

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationItem.title=@"test";
    first =[[FirstViewController alloc]init];
    send=[[SendViewController alloc]init];
    send.delegate=self;
    [self creatBtn];

}

-(void)creatBtn
{
    btn=[UIButton buttonWithType:UIButtonTypeCustom];
    [btn setFrame:CGRectMake(50, 100, 100, 100)];
    [btn setBackgroundColor:[UIColor cyanColor]];
    [btn setTitle:@"block传值" forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(pressBtn) forControlEvents:UIControlEventTouchUpInside];

    btn1=[UIButton buttonWithType:UIButtonTypeCustom];
    [btn1 setFrame:CGRectMake(200, 100, 100, 100)];
    [btn1 setBackgroundColor:[UIColor cyanColor]];
    [btn1 setTitle:@"代理传值" forState:UIControlStateNormal];
    [btn1 addTarget:self action:@selector(pressBtn1) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
    [self.view addSubview:btn1];

}

-(void)pressBtn
{

    //int a = 0;   block 里面不能改变a的值（报错，block下面打印原来的值），但是可以将a的值赋给别人
    //弱引用属性
    //弱引用 self
    __block __weak typeof(self) weakSelf = self;
    __block __weak UIButton *_button = btn;
    first.color=^(UIColor *color){
    _button.backgroundColor=color;

    };

    first.Title=^(NSString *title){
    weakSelf.navigationItem.title=@"block传值";
    //强引用
   // [btn setTitle:title forState:UIControlStateNormal];
    //弱引用
    [_button setTitle:title forState:UIControlStateNormal];

    };
    [self.navigationController pushViewController:first animated:YES];
}

-(void)pressBtn1
{
    [self.navigationController pushViewController:send animated:YES];
}

-(void)sendInForIdea:(NSString *)text
{
    [btn1 setTitle:text forState:UIControlStateNormal];
    self.navigationItem.title=@"代理传值";
}