自己对OC中Block的理解2

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////  ViewController.m//  test_stack_block////  Created by jeffasd on 16/5/18.//  Copyright © 2016年 jeffasd. All rights reserved.//#import "ViewController.h"typedef void(^TestBlock)(int);@interface ViewController ()//@property(nonatomic, copy) void (^)(int) block;@property (nonatomic, copy)TestBlock testBlock;@property (nonatomic, strong) void (^oneBlock)(int);@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];        __block int inta = 2;            //weak类型的block不会进行 自动copy操作，但是此weak类型的block没有    //引用任何外部变量 会被立即转换成 NSGlobalBlock    __weak void (^ stackBlcok)(int) = ^(int var){        //        inta = 3;        //        NSLog(@"the var is %d", var);        //        NSLog(@"the block inline is %@", stackBlcok);            };            NSLog(@"the block is %@", stackBlcok);//    stackBlcok(12);    NSLog(@"the block end is %@", stackBlcok);            //weak类型的block不会进行 自动copy操作，但是此weak类型的block没有    //引用任何外部变量 会被立即转换成 NSGlobalBlock    __weak void (^ weakstackBlcok)(int) = ^(int var){                NSLog(@"the inta is %d", var);//打印var变量不算引用外部变量，var变量是此block自己的变量//        NSLog(@"the inta is %d", inta);//引用外部变量inta 变量 由于所有类型的block创建时都是在stack中创建            };            NSLog(@"the weakstackBlcok is %@", weakstackBlcok);    //    stackBlcok(12);    NSLog(@"the weakstackBlcok end is %@", weakstackBlcok);        //    __weak void (^ weakBlcok)() = ^(){//        ////        //    };//    //    //    NSLog(@"the weakBlcok is %@", weakBlcok);//    //    stackBlcok(12);//    NSLog(@"the weakBlcok end is %@", weakBlcok);                __block void (^weakBlock)() =  ^(){        NSLog(@"fsdfsdf");        return;    };        NSLog(@"the weak block is %@", weakBlock);            NSLog(@"test block type %@", ^{});        NSLog(@"test block type %@", ^{});            self.oneBlock = ^(int vara){        NSLog(@"the vara is %d", vara);    };        NSLog(@"the block is %@", self.oneBlock);    self.oneBlock(56);    NSLog(@"the block end is %@", self.oneBlock);    }- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {    int i = 10;    void (^block)() = ^{i;};        __weak void (^weakBlock)() = ^{i;};        void (^stackBlock)() = ^{};        __weak void (^weakstackBlock)() = ^{};        // ARC情况下        // 创建时，都会在栈中    // <__NSStackBlock__: 0x7fff5fbff730>    NSLog(@"1 %@", ^{i;});        //创建时如果没有引用外部变量，直接转换为__NSGlobalBlock__    NSLog(@"%@", ^{});        // 因为stackBlock为strong类型，且捕获了外部变量，所以赋值时，自动进行了copy    // <__NSMallocBlock__: 0x100206920>    NSLog(@"3 %@", block);        // 如果是weak类型的block，依然不会自动进行copy    // <__NSStackBlock__: 0x7fff5fbff728>    NSLog(@"4 %@", weakBlock);        // 如果block是strong类型，并且没有捕获外部变量，那么就会转换成__NSGlobalBlock__    // <__NSGlobalBlock__: 0x100001110>    NSLog(@"5 %@", stackBlock);        // 如果block是weak类型，并且没有捕获外部变量，那么也会转换成__NSGlobalBlock__    NSLog(@"6 %@", weakstackBlock);        // 在非ARC情况下，产生以下输出    // <__NSStackBlock__: 0x7fff5fbff6d0>    // <__NSStackBlock__: 0x7fff5fbff730>    // <__NSStackBlock__: 0x7fff5fbff700>    // <__NSGlobalBlock__: 0x1000010d0>}@end
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