Block作为方法参数传值的应用

#import "FristViewController.h"
#import "AppDateSource.h"
@interface FristViewController ()
@property(nonatomic,strong)UILabel *showTextLabel;
@end

@implementation FristViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    UILabel *showTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 200, 150, 50)];
    showTextLabel.text = @"帅哥美女";
    showTextLabel.backgroundColor = [UIColor yellowColor];
    showTextLabel.textAlignment = NSTextAlignmentCenter;
    [self.view addSubview:showTextLabel];
    UIButton *sendMesssageBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    sendMesssageBtn.backgroundColor = [UIColor yellowColor];
    [sendMesssageBtn setTitle:@"发送" forState:UIControlStateNormal];
    sendMesssageBtn.frame = CGRectMake(100, 300, 150, 50);
    [sendMesssageBtn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [sendMesssageBtn addTarget:self action:@selector(sendMesssageAction) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:sendMesssageBtn];
    self.showTextLabel = showTextLabel;
    
}
-(void)sendMesssageAction
{
#warning 第四步:block回调,即实现block
    AppDateSource *dataBlock = [[AppDateSource alloc] init];
    //调用方法,实现Block作为方法参数
    [dataBlock sendMessage:@10086 andBlock:^(NSString *stirng) {
        self.showTextLabel.text = stirng;
    }];
    
    //总结:Block作为方法参数传值应用场景:一般是在处理数据的Model层进行使用;具体步骤:
    //1.对Block进行typedef
    //2.声明方法是Block作为方法参数
    //3.实现声明的方法,将要传递的内容传递出去
    //4.实现Block的回调
}

#import <Foundation/Foundation.h>
#warning 第一步:Block的重定义typedef
 typedef void(^AppDateSourceBlock)(NSString *stirng);
@interface AppDateSource : NSObject
#warning 第二步:声明方法,让Block作为方法参数
-(void)sendMessage:(NSNumber *)number andBlock:(AppDateSourceBlock)block;
@end

#import "AppDateSource.h"

@implementation AppDateSource
#warning 第三步:实现Block作为方法参数的那个方法
-(void)sendMessage:(NSNumber *)number andBlock:(AppDateSourceBlock)block
{
    NSString *string = [NSString stringWithFormat:@"%ld",[number integerValue]];
    block(string);
    
}
@end