isMemberOf与isKindOf的区别
这两个方法常常会困惑我们,它们有什么区别呢?
定义
首先,我们来看看它们的定义。
isKindOfClass:
官方解释:Returns a Boolean value that indicates whether the receiver is an instance of given class or an instance of any class that inherits from that class.
isMemberOfClass:
官方解释:Returns a Boolean value that indicates whether the receiver is an instance of a given class.
使用
关于使用,在网上看到一个很形象的例子,这里就直接拿来用了。
这里有两个类,分别是继承于NSObject的Person,Person的Teacher
#import <Foundation/Foundation.h>
@interface Person : NSObject
{
NSString *name;
}
-(void)setName:(NSString*)n;
@end
#import "Person.h"
@implementation Person
-(void)setName:(NSString *)n
{
name = n;
}
@end
#import "Person.h"
@interface Teacher : Person
-(void)teach;
@end
#import "Teacher.h"
@implementation Teacher
-(void)teach
{
NSLog(@"我教数学");
}
@end
使用isKindOfClass的例子:
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
Person *person = [[Person alloc] init];
Teacher *teacher = [[Teacher alloc] init];
//YES
if ([teacher isKindOfClass:[Teacher class]]) {
NSLog(@"teacher 是 Teacher类或Teacher的子类");
}
//YES
if ([teacher isKindOfClass:[Person class]]) {
NSLog(@"teacher 是 Person类或Person的子类");
}
//YES
if ([teacher isKindOfClass:[NSObject class]]) {
NSLog(@"teacher 是 NSObject类或NSObject的子类");
}
[person release];
[teacher release];
[pool release];
输出结果:
2012-07-04 14:34:17.315 ObjectiveCTest[2595:f803] teacher 是 Teacher类或Teacher的子类
2012-07-04 14:34:17.316 ObjectiveCTest[2595:f803] teacher 是 Person类或Person的子类
2012-07-04 14:34:17.316 ObjectiveCTest[2595:f803] teacher 是 NSObject类或NSObject的子类
使用isMemberOfClass的例子:
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
Person *person = [[Person alloc] init];
Teacher *teacher = [[Teacher alloc] init];
//YES
if ([teacher isMemberOfClass:[Teacher class]]) {
NSLog(@"teacher Teacher类的成员");
}
//NO
if ([teacher isMemberOfClass:[Person class]]) {
NSLog(@"teacher Person类的成员");
}
//NO
if ([teacher isMemberOfClass:[NSObject class]]) {
NSLog(@"teacher NSObject类的成员");
}
[person release];
[teacher release];
[pool release];
输出结果:
2012-07-04 14:23:07.965 ObjectiveCTest[2460:f803] teacher Teacher类的成员
看了这两个例子,应该就会明白了。