1.将某个对象写入文件时会调用*在这个方法中说清楚哪些属性需要存储

- (void)encodeWithCoder:(NSCoder*)encoder

{

[encoderencodeObject:self.noforKey:@"no"];

[encoderencodeInt:self.ageforKey:@"age"];

[encoderencodeDouble:self.heightforKey:@"height"];

}

2.*从文件中解析对象时会调用在这个方法中说清楚哪些属性需要存储

- (id)initWithCoder:(NSCoder*)decoder

{

if(self= [superinit]) {

//读取文件的内容

self.no= [decoderdecodeObjectForKey:@"no"];

self.age= [decoderdecodeIntForKey:@"age"];

self.height= [decoderdecodeDoubleForKey:@"height"];

}

returnself;

}

// 2.归档模型对象

// 2.1.获得Documents的全路径

NSString*doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)lastObject];

// 2.2.获得文件的全路径

NSString*path = [docstringByAppendingPathComponent:@"stu.data"];

// 2.3.将对象归档

[NSKeyedArchiverarchiveRootObject:stutoFile:path];

NSString*doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)lastObject];

// 2.获得文件的全路径

NSString*path = [docstringByAppendingPathComponent:@"stu.data"];

// 3.从文件中读取MJStudent对象

MJStudent*stu = [NSKeyedUnarchiverunarchiveObjectWithFile:path];