iOS 類增加成員變量

RT

// 增加成員變量
#import <Foundation/Foundation.h>

@interface NSObject (AddProperty)
@property (nonatomic,strong) NSString *stringProperty;
@property (nonatomic,assign) NSInteger integerProperty;
@end

#import "NSObject+AddProperty.h"
#import <objc/runtime.h>

//objc_getAssociatedObject和objc_setAssociatedObject都需要指定一個固定的地址，這個固定的地址值用來表示屬性的key，起到一個常量的作用。
static const void *StringProperty = &StringProperty;
static const void *IntegerProperty = &IntegerProperty;
//static char IntegerProperty;
@implementation NSObject (AddProperty)

@dynamic stringProperty;

//set
-(void)setStringProperty:(NSString *)stringProperty{
    //use that a static const as the key
    objc_setAssociatedObject(self, StringProperty, stringProperty, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    //use that property's selector as the key:
    //objc_setAssociatedObject(self, @selector(stringProperty), stringProperty, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
//get
-(NSString *)stringProperty{
    return objc_getAssociatedObject(self, StringProperty);
}
//set
-(void)setIntegerProperty:(NSInteger)integerProperty{
    NSNumber *number = [[NSNumber alloc]initWithInteger:integerProperty];
    objc_setAssociatedObject(self, IntegerProperty, number, OBJC_ASSOCIATION_ASSIGN);
}
//get
-(NSInteger)integerProperty{
    return [objc_getAssociatedObject(self, IntegerProperty) integerValue];
}

@end

// 獲取成員變量列表

@interface NSObject (Property)
-(NSDictionary *)propertyDictionary;

+ (NSArray *)classPropertyList;
@end

#import "NSObject+Property.h"
#import <Foundation/Foundation.h>
#import <objc/runtime.h>

@implementation NSObject (Property)
-(NSDictionary *)propertyDictionary
{
    //創建可變字典
    NSMutableDictionary *dict = [NSMutableDictionary dictionary];
    unsigned int outCount;
    objc_property_t *props = class_copyPropertyList([self class], &outCount);
    for(int i=0;i<outCount;i++){
        objc_property_t prop = props[i];
        NSString *propName = [[NSString alloc]initWithCString:property_getName(prop) encoding:NSUTF8StringEncoding];
        id propValue = [self valueForKey:propName];
        if(propValue){
            [dict setObject:propValue forKey:propName];
        }
    }
    free(props);
    return dict;
}

+ (NSArray *)classPropertyList {
    NSMutableArray *allProperties = [[NSMutableArray alloc] init];

    unsigned int outCount;
    objc_property_t *props = class_copyPropertyList(self, &outCount);
    for (int i = 0; i < outCount; i++) {
        objc_property_t prop = props[i];

        NSString *propName = [[NSString alloc]initWithCString:property_getName(prop) encoding:NSUTF8StringEncoding];

        if (propName) {
            [allProperties addObject:propName];
        }
    }
    free(props);
    return [NSArray arrayWithArray:allProperties];
}
@end

原文地址：https://github.com/shaojiankui/iOS-Categories/tree/master/Categories/Foundation/NSObject