.main.m文件

/*

    定义Student类
    1、属性有age,name,gender; 2、age使⽤用assign,name使⽤用retain,gender使⽤用copy; 3、重写age、name、gender的setter和getter⽅方法。
    */

if 0

    
    Student *stu = [[Student alloc] init];
    
    // KVC 间接访问的一种方式
    [stu setValue:@"longlong" forKey:@"name"];
    NSLog(@"%@", [stu valueForKey:@"name"]);
    
    NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:@"long", @"name", @"m", @"gender", @"23", @"age", @"200", @"id", nil];
    // 重要方法   就字典中的内容按照key值 对应的写入对象中
    [stu setValuesForKeysWithDictionary:dic];
    NSLog(@"%@ %@",stu.name, stu.gender);
    
    

Student.h文件

@interface Student : NSObject
@property (nonatomic, retain) NSString *name;
@property (nonatomic, assign) NSInteger age;
@property (nonatomic, copy) NSString *gender;
@property (nonatomic, copy) NSString *idstr;

• (instancetype)initWithName:(NSString *)name

                       age:(NSInteger)age
                    gender:(NSString *)gender;

• (instancetype)StudentWithName:(NSString *)name

                          age:(NSInteger)age
                       gender:(NSString *)gender;
  

Student.m文件

@synthesize age = _age;
@synthesize name = _name;
@synthesize gender = _gender;

• (void)dealloc
  {
  [_name release];
  [_gender release];
  [super dealloc];
  }

• (void)setName:(NSString *)name {
  if (_name != name) {

  [_name release];
  _name = [name retain];

  }
  }

• (NSString *)name {
  return [[_name retain] autorelease];
  }

• (void)setGender:(NSString *)gender {
  if (_gender != gender) {

  [_gender release];
  _gender = [gender copy];

  }
  }

• (NSString *)gender {
  return [[_gender retain] autorelease];
  }
• (void)setAge:(NSInteger)age {
  _age = age;
  }
• (NSInteger)age {
  return _age;
  }

• (instancetype)initWithName:(NSString )name age:(NSInteger)age gender:(NSString )gender
  {
  self = [super init];
  if (self) {

  self.name = name;
  self.gender = gender;
  self.age = age;

  }
  return self;
  }

• (instancetype)StudentWithName:(NSString )name age:(NSInteger)age gender:(NSString )gender
  {
  Student *p = [[Student alloc] initWithName:name age:age gender:gender];
  return [p autorelease];
  }

//

• (void)setValue:(id)value forKey:(NSString *)key
  {

  [super setValue:value forKey:key];
  if ([key isEqualToString:@"age"]) {

  // 其他类型转NSInteger类型
  self.age = [value integerValue];

  }
  }

// 重定义setValue // KVC 时 不崩溃

• (void)setValue:(id)value forUndefinedKey:(NSString *)key
  {

  // 如上面

  }