标签:pre nsobject data knn 声明 str ons ref his
注释在代码中;请参考傻瓜学编程之block_3
import "People.h" @interface People() { int yourNameis; } @end @implementation People -(instancetype)init{ if ( [super init]) { [self myBlcokTest]; } return self; } - (void)myBlcokTest{ int ddkknn = 555555; char bbb = ‘3‘; const char *fmt = &bbb; void (^blk)()=^{ printf("%d",ddkknn); printf("%s",fmt); }; blk(); } // 变量直接添加 属性生成_xxxx; struct People_IMPL { struct NSObject_IMPL NSObject_IVARS; int yourNameis; NSString *_thisIsPro; }; /** 1、结构体内部生成的成员变量与声明的成员变量的类型相同; 2、block语法中没有使用的自动变量不会被追加,只有在block语法中使用的自动变量才会被追加; 3、根据构造函数传递过来的参数对追加的成员变量进行初始化; */ struct __People__myBlcokTest_block_impl_0 { struct __block_impl impl; struct __People__myBlcokTest_block_desc_0* Desc; int ddkknn; const char *fmt; __People__myBlcokTest_block_impl_0(void *fp, struct __People__myBlcokTest_block_desc_0 *desc, int _ddkknn, const char *_fmt, int flags=0) : ddkknn(_ddkknn), fmt(_fmt) { impl.isa = &_NSConcreteStackBlock; impl.Flags = flags; impl.FuncPtr = fp; Desc = desc; } // 相当于: __People__myBlcokTest_block_impl_0(void *fp, struct __People__myBlcokTest_block_desc_0 *desc, int _ddkknn, const char *_fmt, int flags=0) : ddkknn(_ddkknn), fmt(_fmt) { impl.isa = &_NSConcreteStackBlock; impl.Flags = flags; impl.FuncPtr = fp; Desc = desc; ddkknn = 5555; fmt = ‘3‘; } }; //此时使用的是保存在__People__myBlcokTest_block_impl_0结构体实例的成员变量中那些自动变量的值 即(int ddkknn; //const char *fmt;) 也就是截获自动变量 就是在执行block时,block所使用的自动变量保存在block 的结构体实例中; static void __People__myBlcokTest_block_func_0(struct __People__myBlcokTest_block_impl_0 *__cself) { int ddkknn = __cself->ddkknn; // bound by copy const char *fmt = __cself->fmt; // bound by copy printf("%d",ddkknn); printf("%s",fmt); } static struct __People__myBlcokTest_block_desc_0 { size_t reserved; size_t Block_size; } __People__myBlcokTest_block_desc_0_DATA = { 0, sizeof(struct __People__myBlcokTest_block_impl_0)}; static void _I_People_myBlcokTest(People * self, SEL _cmd) { int ddkknn = 555555; char bbb = ‘3‘; const char *fmt = &bbb; void (*blk)()=((void (*)())&__People__myBlcokTest_block_impl_0((void *)__People__myBlcokTest_block_func_0, &__People__myBlcokTest_block_desc_0_DATA, ddkknn, fmt)); ((void (*)(__block_impl *))((__block_impl *)blk)->FuncPtr)((__block_impl *)blk); }
标签:pre nsobject data knn 声明 str ons ref his
原文地址:http://www.cnblogs.com/xiaowuqing/p/7648365.html