type的补充还有一些简单说明

type定义参考:https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html

    2."v@:@",解释v-返回值void类型,@-self指针id类型,:-SEL指针SEL类型,@-函数第一个参数为id类型

    3."@@:",解释@-返回值id类型,@-self指针id类型,:-SEL指针SEL类型,

d.注册到运行时环境

    objc_registerClassPair(kclass);

e.实例化类

    id instance = [[kclass alloc] init];

f.给变量赋值

   object_setInstanceVariable(instance, "expression", "1+1");

g.获取变量值

    void * value = NULL;

    object_getInstanceVariable(instance, "expression", &value);

h.调用函数

    [instance performSelector:@selector(getExpressionFormula)];

type的补充还有一些简单说明

type定义参考:https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html

    2."v@:@",解释v-返回值void类型,@-self指针id类型,:-SEL指针SEL类型,@-函数第一个参数为id类型

    3."@@:",解释@-返回值id类型,@-self指针id类型,:-SEL指针SEL类型,

d.注册到运行时环境

    objc_registerClassPair(kclass);

e.实例化类

    id instance = [[kclass alloc] init];

f.给变量赋值

   object_setInstanceVariable(instance, "expression", "1+1");

g.获取变量值

    void * value = NULL;

    object_getInstanceVariable(instance, "expression", &value);

h.调用函数

    [instance performSelector:@selector(getExpressionFormula)];