在定义model的时候，经常会写一大堆的属性声明和属性赋值，为了避免重复劳动，我们可以写个小程序拼接出属性声明的代码，赋值可以利用kvc setValuesForKeysWithDictionary的方法
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自动生成属性
生成属性代码可以在项目中写个分类 NSObject+AutoProperty
.h
//
// NSObject+AutoProperty.h
// GCDDemo
//
// Created by z on 2017/1/19.
// Copyright © 2017年 ja. All rights reserved.
// 传入数据字典自动生成属性代码
#import <Foundation/Foundation.h>
@interface NSObject (AutoProperty)
+ (void)autoPropertyWith:(NSDictionary *)dic;
@end
.m
#import "NSObject+AutoProperty.h"
@implementation NSObject (AutoProperty)
+ (void)autoPropertyWith:(NSDictionary *)dic
{
NSMutableString *proprety = [[NSMutableString alloc] init];
//遍历数组 生成声明属性的代码，例如 @property (nonatomic, copy) NSString str
//打印出来后 command+c command+v
[dic enumerateKeysAndObjectsUsingBlock:^(id _Nonnull key, id _Nonnull obj, BOOL * _Nonnull stop) {
NSString *str;
NSLog(@"%@",[obj class]);
if ([obj isKindOfClass:NSClassFromString(@"__NSCFString")] || [obj isKindOfClass:NSClassFromString(@"NSTaggedPointerString")] || [obj isKindOfClass:NSClassFromString(@"__NSCFConstantString")]) {
str = [NSString stringWithFormat:@"@property (nonatomic, strong) NSString *%@;",key];
}
if ([obj isKindOfClass:NSClassFromString(@"__NSCFNumber")]) {
str = [NSString stringWithFormat:@"@property (nonatomic, assign) int %@;",key];
}
if ([obj isKindOfClass:NSClassFromString(@"__NSCFArray")] || [obj isKindOfClass:[NSArray class]]) {
str = [NSString stringWithFormat:@"@property (nonatomic, strong) NSArray *%@;",key];
}
if ([obj isKindOfClass:NSClassFromString(@"__NSCFDictionary")] || [obj isKindOfClass:[NSDictionary class]]) {
str = [NSString stringWithFormat:@"@property (nonatomic, strong) NSDictionary *%@;",key];
}
if ([obj isKindOfClass:NSClassFromString(@"__NSCFBoolean")]) {
str = [NSString stringWithFormat:@"@property (nonatomic, assign) BOOL %@;",key];
}
[proprety appendFormat:@"\n%@\n",str];
}];
NSLog(@"%@",proprety);
}
@end
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属性赋值
方法一 可以利用kvc setValuesForKeysWithDictionary的方法
原理：遍历字典的所有key，然后从model里查找属性赋值
#import "JAViewModel.h"
@implementation JAViewModel
+ (instancetype)makeModel:(NSDictionary *)dic
{
JAViewModel *model = [[JAViewModel alloc] init];
[model setValuesForKeysWithDictionary:dic];
return model;
}
//重写父类 避免dic里面有没有定义的属性会crash的情况
- (void)setValue:(id)value forUndefinedKey:(NSString *)key
{
// to do something
}
@end
方法二
原理：利用runtime获取model的属性列表，然后从字典里面取出value给属性赋值
/**
* 自动给属性赋值
*
* @param dict JSON字典/模型字典
*/
+ (instancetype)setPropertyValuesWithDict:(NSDictionary *)dict
{
//原理：利用runtime获取model的属性列表，然后从字典里面取出value给属性赋值
// 创建实例对象
id obj = [[self alloc] init];
// 获取属性列表
/**
* class_copyIvarList(Class cls, unsigned int *outCount) 获取成员变量列表
* class 获取那个类的属性
* outCount 获取的属性总个数
*/
unsigned int count = 0;
Ivar *ivarList = class_copyIvarList(self, &count);
//遍历属性列表
for (int i = 0; i < count; i ++) {
Ivar aivar = ivarList[i];
//获取属性名字（带下划线）
NSString *_propertyName = [NSString stringWithUTF8String:ivar_getName(aivar)];
//获取属性type
NSString *propertyType = [NSString stringWithUTF8String:ivar_getTypeEncoding(aivar)];
//属性名字 不带下划线
NSString *key = [_propertyName substringFromIndex:1];
//通过属性名从字典里面取出value
id value = [dict objectForKey:key];
/*二级model*/
//当value时字典，并且属性是自定义的model，把字典（value）转换成model
//当propertyType是自定义的model 那么此时 propertyType = @"@\"AddressModel\""，所以我们要截取字符串，把自定义的model名字取出来
NSString *nsdictStr = @"@\"NSDictionary\"";
if ([value isKindOfClass:[NSDictionary class] ] && ![propertyType isEqualToString:nsdictStr]) {
NSRange range = [propertyType rangeOfString:@"\""];
propertyType = [propertyType substringFromIndex:range.location + range.length];
range = [propertyType rangeOfString:@"\""];
propertyType = [propertyType substringToIndex:range.location];
Class modelClass = NSClassFromString(propertyType);
if (modelClass) {
NSLog(@"propertyType == %@",propertyType);
value = [modelClass setPropertyValuesWithDict:value];
}
}
if (value) {
[obj setValue:value forKey:key];
}
}
return obj;
}
