用字典给Model赋值

此篇教程讲述通过runtime扩展NSObject，可以直接用字典给Model赋值，这是相当有用的技术呢。

源码：

NSObject+Properties.h 与 NSObject+Properties.m

//
//  NSObject+Properties.h
//
//  Created by YouXianMing on 14-9-4.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//#import <Foundation/Foundation.h>@interface NSObject (Properties)- (void)setDataDictionary:(NSDictionary*)dataDictionary;
- (NSDictionary *)dataDictionary;@end

//
//  NSObject+Properties.m
//
//  Created by YouXianMing on 14-9-4.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//#import "NSObject+Properties.h"
#import <objc/runtime.h>@implementation NSObject (Properties)#pragma public - 公开方法- (void)setDataDictionary:(NSDictionary*)dataDictionary
{[self setAttributes:dataDictionary obj:self];
}- (NSDictionary *)dataDictionary
{// 获取属性列表NSArray *properties = [self propertyNames:[self class]];// 根据属性列表获取属性值return [self propertiesAndValuesDictionary:self properties:properties];
}#pragma private - 私有方法// 通过属性名字拼凑setter方法
- (SEL)getSetterSelWithAttibuteName:(NSString*)attributeName
{NSString *capital = [[attributeName substringToIndex:1] uppercaseString];NSString *setterSelStr = \[NSString stringWithFormat:@"set%@%@:", capital, [attributeName substringFromIndex:1]];return NSSelectorFromString(setterSelStr);
}// 通过字典设置属性值
- (void)setAttributes:(NSDictionary*)dataDic obj:(id)obj
{// 获取所有的key值NSEnumerator *keyEnum = [dataDic keyEnumerator];// 字典的key值(与Model的属性值一一对应)id attributeName = nil;while ((attributeName = [keyEnum nextObject])){// 获取拼凑的setter方法SEL sel = [obj getSetterSelWithAttibuteName:attributeName];// 验证setter方法是否能回应if ([obj respondsToSelector:sel]){id value      = nil;id tmpValue   = dataDic[attributeName];if([tmpValue isKindOfClass:[NSNull class]]){// 如果是NSNull类型，则value值为空value = nil;}else{value = tmpValue;}// 执行setter方法[obj performSelectorOnMainThread:selwithObject:valuewaitUntilDone:[NSThread isMainThread]];}}
}// 获取一个类的属性名字列表
- (NSArray*)propertyNames:(Class)class
{NSMutableArray  *propertyNames = [[NSMutableArray alloc] init];unsigned int     propertyCount = 0;objc_property_t *properties    = class_copyPropertyList(class, &propertyCount);for (unsigned int i = 0; i < propertyCount; ++i){objc_property_t  property = properties[i];const char      *name     = property_getName(property);[propertyNames addObject:[NSString stringWithUTF8String:name]];}free(properties);return propertyNames;
}// 根据属性数组获取该属性的值
- (NSDictionary*)propertiesAndValuesDictionary:(id)obj properties:(NSArray *)properties
{NSMutableDictionary *propertiesValuesDic = [NSMutableDictionary dictionary];for (NSString *property in properties){SEL getSel = NSSelectorFromString(property);if ([obj respondsToSelector:getSel]){NSMethodSignature  *signature  = nil;signature                      = [obj methodSignatureForSelector:getSel];NSInvocation       *invocation = [NSInvocation invocationWithMethodSignature:signature];[invocation setTarget:obj];[invocation setSelector:getSel];NSObject * __unsafe_unretained valueObj = nil;[invocation invoke];[invocation getReturnValue:&valueObj];//assign to @"" stringif (valueObj == nil){valueObj = @"";}propertiesValuesDic[property] = valueObj;}}return propertiesValuesDic;
}@end

测试用Model

Model.h 与 Model.m

//
//  Model.h
//  Runtime
//
//  Created by YouXianMing on 14-9-5.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//#import <Foundation/Foundation.h>@interface Model : NSObject@property (nonatomic, strong) NSString      *name;
@property (nonatomic, strong) NSNumber      *age;
@property (nonatomic, strong) NSDictionary  *addressInfo;
@property (nonatomic, strong) NSArray       *events;@end

//
//  Model.m
//  Runtime
//
//  Created by YouXianMing on 14-9-5.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//#import "Model.h"@implementation Model@end

使用时的情形

//
//  AppDelegate.m
//  Runtime
//
//  Created by YouXianMing on 14-9-5.
//  Copyright (c) 2014年 YouXianMing. All rights reserved.
//#import "AppDelegate.h"
#import "NSObject+Properties.h"
#import "Model.h"@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{// 初始化modelModel *model = [Model new];// 通过字典赋值model.dataDictionary = @{@"name"        : @"YouXianMing",@"age"         : @26,@"addressInfo" : @{@"HuBei": @"WeiHan"},@"events"      : @[@"One", @"Two", @"Three"]};// 打印出属性值NSLog(@"%@", model.dataDictionary);return YES;
}@end

打印的信息：

2014-09-05 21:03:54.840 Runtime[553:60b] {

    addressInfo =     {

        HuBei = WeiHan;

    };

    age = 26;

    events =     (

        One,

        Two,

        Three

    );

    name = YouXianMing;

}

以下是两段核心代码(符合单一职能)：