简单使用runtime将具有相同属性两个类赋值，目前只是简单考虑某些常用属性类型，包含如下：
NSString、NSInteger、NSNumber、BOOL、NSDate、int、double、long、NS_ENUM(NSUInteger, ENUM_NAME)

代码只是拿到属性，找到对应值，直接赋值，同名，不同类型还没考虑，应该还有没考虑的情况

例子：

#import "NSObject+WLClassTransform.h"

AClass *aClass = [[AClass alloc] init];
aClass.xx = @"xx";
aClass.yy = @"yy";

BClass *bClass = [aClass transformToClass:BClass.class];
NSLog(@"bClass.xx=[%@]", bClass.xx); //输出 xx

NSObject+WLClassTransform源码：

• NSObject+WLClassTransform.h

//
//  NSObject+WLClassTransform.h
//  libWeever
//
//  Created by LuYiHuang on 2019/3/24.
//  Copyright © 2019 Weever. All rights reserved.
//

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface NSObject (WLClassTransform)

/**
 将当前类的属性值，全赋值给toClass对应存在的属性

 @param toClass 需要赋值的Class
 @return toClass的实例对象
 */
- (Class)transformToClass:(Class)toClass;

@end

NS_ASSUME_NONNULL_END

• NSObject+WLClassTransform.m

//
//  NSObject+WLClassTransform.m
//  libWeever
//
//  Created by LuYiHuang on 2019/3/24.
//  Copyright © 2019 Weever. All rights reserved.
//

#import "NSObject+WLClassTransform.h"
#import "objc/runtime.h"

@implementation NSObject (WLClassTransform)

- (Class)transformToClass:(Class)toClass {
    id model = [[toClass alloc] init];
    
    unsigned int outCount;
    objc_property_t *properties = class_copyPropertyList(toClass, &outCount);
    for ( int i = 0; i < outCount; i++) {
        objc_property_t property = properties[i];
        const char *charName = property_getName(property);
        NSString *propertyName = [NSString stringWithUTF8String:charName];
        id propertyValue = [self propertyValueByName:propertyName]; //循环获取，效率？？
        //NSLog(@"%s %@=%@", __func__, propertyName, propertyValue);
        [model setValue:propertyValue forKey:propertyName];
    }
    free(properties);
    
    return model;
}

/**
 获取当前类的存在该属性名对应的属性值

 @param name 查找的属性名
 @return 查找的属性名对应的属性值
 */
- (id)propertyValueByName:(NSString *)name {
    id propertyValue = nil;
    
    unsigned int outCount;
    objc_property_t *properties = class_copyPropertyList(self.class, &outCount);
    for ( int i = 0; i < outCount; i++) {
        objc_property_t property = properties[i];
        const char *charName = property_getName(property);
        NSString *propertyName = [NSString stringWithUTF8String:charName];
        //查找的属性名，是当前类存在的属性
        if ([propertyName isEqualToString:name]) {
            propertyValue = [self valueForKey:(NSString *)propertyName];
            //NSLog(@"%s %@=%@", __func__, propertyName, propertyValue);
            break;
        }
    }
    free(properties);
    
    return propertyValue;
}

@end