OC語法之Block

//
//  main.m
//  Block
//
//  Created by New-World on 13-11-11.
//  Copyright (c) 2013年 Gary. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Button.h"
#import "Person.h"

typedef int (^MySum)(int,int); 
void test()
{
    int (^Sum)(int a,int b)=^(int a,int b){
        return a+b;
    };
    NSLog(@"和是：%i",Sum(10,30));
}
void test2()
{
    __block int c=8;
    MySum sum=^(int a,int b){//block可以訪問，但不能修改外部變量
        c=19;//如果必須要修改，要加__block關鍵字修飾
        NSLog(@"%i",c);
        return a+b;
    };
    NSLog(@"%i",sum(10,10));
}
#pragma mark 作爲參數傳遞的block
int test3(int (^Sum)(int,int))
{
    return Sum(20,20);
}

void test4(void (^minus)(int))
{
    minus(12);
}

void test5(int a,int (^Sum)(int,int),void (^minus)(int)){
    
}

#pragma mark block在對象間的傳遞

int main(int argc, const char * argv[])
{

    @autoreleasepool {
        Button *btn=[[Button new] autorelease];
        btn.block=^(Button *btn){
            NSLog(@"按鈕-%@被點擊了",btn);
        };
        [btn click];//回調
        
        
        
        void (^minus)(int)=^(int c){
            NSLog(@"%i",c);
        };
        test4(minus);
        
        
        int (^Sum)(int,int)=^(int a,int b){
            return a+b;
        };
        NSLog(@"兩者的和是：%i",test3(Sum));
        
        
        Person *p=[Person new];
        [p test:^int(int a, int b) {
            return a-b;
        }];
        [p release];
        
    }
    return 0;
}

////////////////////////////////////////////////
#import <Foundation/Foundation.h>
@class Button;
typedef void (^ButtonBlock) (Button *);


@interface Button : NSObject

@property (nonatomic,assign) ButtonBlock block;//Block是一種數據類型，所以不用加*
-(void)click;
@end
////////////////////////////////////////////////
#import "Button.h"

@implementation Button
-(void)click{
    _block(self);
}
@end
///////////////////////////////////////////////
#import <Foundation/Foundation.h>
typedef int (^Minus)(int,int);

@interface Person : NSObject

-(void)test:(Minus)minus;

@end
/////////////////////////////////////////////////
#import "Person.h"

@implementation Person

-(void)test:(Minus)minus{//test方法負責傳遞參數，調用者進行方法的具體實現
    int x=minus(20,30);
    NSLog(@"block在對象間的傳遞：%i",x);
}

@end