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
在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;
}
}
}
