RunTime的一些知识点之方法

RunTime的一些知识点之方法

获取已注册 class 的数量

/*
 *   buffer   class 数组值的缓存，所有注册的class 的数量， 通过传入null来获取所有的注册的class
 *   bufferCount   申请缓存空间指针的数量
 *   On return, this function fills in only this number of elements. If this number is less
 *  than the number of registered classes, this function returns an arbitrary subset of the registered classes.
 *
 */
OBJC_EXPORT int objc_getClassList(Class *buffer, int bufferCount)
    OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);

例子

     int numClasses;   
     Class *classes = NULL;
    
    classes = NULL;
    numClasses = objc_getClassList(NULL,0);
    NSLog(@"Number of classes: %d", numClasses);
    
    if (numClasses >0 )
    {
        classes = (__unsafe_unretained Class *)malloc(sizeof(Class) * numClasses);
        numClasses = objc_getClassList(classes, numClasses);
        for (int i = 0; i < numClasses; i++) {
            NSLog(@"Class name: %s",class_getName(classes[i]));
        }
        free(classes);   
     }

获取注册类列表

OBJC_EXPORT Class *objc_copyClassList(unsigned int *outCount)
    OBJC_AVAILABLE(10.7, 3.1, 9.0, 1.0);

unsigned int outCount;
Class *classes = objc_copyClassList(&outCount);
for (int i = 0; i < outCount; i++) {
    NSLog(@"%s", class_getName(classes[i]));
}
free(classes);

获取class 名称

OBJC_EXPORT const char *class_getName(Class cls) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

是否为元类

OBJC_EXPORT BOOL class_isMetaClass(Class cls) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

获取父类

OBJC_EXPORT Class class_getSuperclass(Class cls) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

设置父类

/*
* 返回旧的的superclass
*/
OBJC_EXPORT Class class_setSuperclass(Class cls, Class newSuper) 
    __OSX_DEPRECATED(10.5, 10.5, "not recommended") 
    __IOS_DEPRECATED(2.0, 2.0, "not recommended") 
    __TVOS_DEPRECATED(9.0, 9.0, "not recommended") 
    __WATCHOS_DEPRECATED(1.0, 1.0, "not recommended");

获取class的版本信息

OBJC_EXPORT int class_getVersion(Class cls)
    OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);

设置版本信息

OBJC_EXPORT void class_setVersion(Class cls, int version)
    OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);

获取实例化大小

// bytes
OBJC_EXPORT size_t class_getInstanceSize(Class cls) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

获取实例化变量

OBJC_EXPORT Ivar class_getInstanceVariable(Class cls, const char *name)
    OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);

OBJC_EXPORT Ivar class_getClassVariable(Class cls, const char *name) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

获取实例变量列表

OBJC_EXPORT Ivar *class_copyIvarList(Class cls, unsigned int *outCount) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

获取实例化方法列表

OBJC_EXPORT Method class_getInstanceMethod(Class cls, SEL name)
    OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);

获取类方法列表

OBJC_EXPORT Method class_getClassMethod(Class cls, SEL name)
    OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);

获取方法的实现

OBJC_EXPORT IMP class_getMethodImplementation(Class cls, SEL name) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

判断方法是否响应

OBJC_EXPORT BOOL class_respondsToSelector(Class cls, SEL sel) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);

拷贝方法列表

OBJC_EXPORT Method *class_copyMethodList(Class cls, unsigned int *outCount) 
    OBJC_AVAILABLE(10.5, 2.0, 9.0, 1.0);