runtime绑定属性方法字典转模型

2017-06-12  本文已影响28人  那个谁_5207

runtime动态绑定属性  

首先创建一个分类以NSString为例

在NSString+apping.h  中加入了一个number属性

@interface NSString (apping)

@property(nonatomic, assign) NSInteger number;

@end

NSString+apping.m中  用关键字@dynamic修饰number属性  @dynamic的作用苹果文档翻译后的意思大概是:您可以使用@ dynamic关键字告诉编译器,您将通过直接或在运行时使用其他机制(例如动态加载代码或动态方法解析)来实现由属性所隐含的API契约。它抑制了如果编译器无法找到合适的实现,则会生成的警告。您应该只使用它,如果您知道方法将在运行时可用。 因为是动态绑定需要导入objc/runtime头文件,具体实现如下

#import <objc/runtime.h>

@dynamic number;

static char stringNumber;

- (void)setNumber:(NSInteger)number{

objc_setAssociatedObject(self, &stringNumber, [NSString stringWithFormat:@"%ld",number], OBJC_ASSOCIATION_COPY);

}

- (NSInteger)number{

return [objc_getAssociatedObject(self, &stringNumber) integerValue];

}


runtime实现字典转模型

创建名为person的Model类添加字典转换方法

Person.h

@interface Person : NSObject

@property(nonatomic, copy)NSString *name;

@property(nonatomic, copy)NSString *phone;

@property(nonatomic, assign)NSInteger sex;

@property(nonatomic, copy)NSString *age;

+ (instancetype)modelWithDic:(NSDictionary*)dic;


Person.m

#import <objc/runtime.h>

//字典转模型


+ (instancetype)modelWithDic:(NSDictionary*)dic{

id objc = [[self alloc] init];

unsigned int count = 0;

Ivar *ivarList = class_copyIvarList(self, &count);

for (int i = 0; i < count; i ++) {

Ivar ivar = ivarList[i];

NSString *ivarName = [NSString stringWithUTF8String:ivar_getName(ivar)];

NSString *key = [ivarName substringFromIndex:1];

id value = dic[key];

if (value) {

[objc setValue:value forKey:key];

}

}

return objc;

}

runtime动态修改属性值

在ViewController.m中导入Person  创建一个person属性

@interface ViewController ()

@property(nonatomic, strong)Person *person;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

_person = [Person modelWithDic:@{@"name":@"niyuanbo", @"phone":@"18883278185", @"sex":@1, @"age":@"33"}];

[self change];

//打印出的age为30

NSLog(@"%@, %@  %ld %@", _person.name, _person.phone,_person.sex,_person.age);



}

- (void)change{

unsigned int count = 0;

Ivar *ivar = class_copyIvarList([self.person class], &count);

for (int i = 0; i < count; i ++) {

Ivar var = ivar[i];

const char *varname = ivar_getName(var);

NSString *name = [NSString stringWithUTF8String:varname];

if ([name isEqualToString:@"_age"]) {

object_setIvar(self.person, var, @"30");

break;

}

}

}

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