runtime動態(tài)綁定屬性??
首先創(chuàng)建一個分類以NSString為例
在NSString+apping.h? 中加入了一個number屬性
@interface NSString (apping)
@property(nonatomic, assign) NSInteger number;
@end
在NSString+apping.m中? 用關(guān)鍵字@dynamic修飾number屬性? @dynamic的作用蘋果文檔翻譯后的意思大概是：您可以使用@ dynamic關(guān)鍵字告訴編譯器，您將通過直接或在運行時使用其他機(jī)制(例如動態(tài)加載代碼或動態(tài)方法解析)來實現(xiàn)由屬性所隱含的API契約。它抑制了如果編譯器無法找到合適的實現(xiàn)，則會生成的警告。您應(yīng)該只使用它，如果您知道方法將在運行時可用。 因為是動態(tài)綁定需要導(dǎo)入objc/runtime頭文件,具體實現(xiàn)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實現(xiàn)字典轉(zhuǎn)模型
創(chuàng)建名為person的Model類添加字典轉(zhuǎn)換方法
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>
//字典轉(zhuǎn)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動態(tài)修改屬性值
在ViewController.m中導(dǎo)入Person? 創(chuàng)建一個person屬性
@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為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;
}
}
}
