-(BOOL) isKindOfClass: classObj
判斷是否是這個(gè)類氢伟，包括這個(gè)類的子類和父類的實(shí)例撰洗；
<code>
-(BOOL)isKindOfClass:(Class)cls {
for (Class tcls = [self class]; tcls; tcls = tcls->superclass) {
if (tcls == cls) return YES;
}
return NO;
}
</code>
isMemberOfClass
-(BOOL) isMemberOfClass: classObj 判斷是否是這個(gè)類的實(shí)例,不包括子類或者父類；
<code>
-(BOOL)isMemberOfClass:(Class)cls {
return [self class] == cls;
}
</code>
