plist 文件， 全名是 Property List 因为文件以 .plist 结尾，所以通常叫做 plist 文件。最外层的 type 只有 字典和数组两种类型。
支持的数据类型
NSData NSString NSNumber NSDate NSArray NSDictionary 全部都是不可变的
创建方式
1.手动创建
barneyzhaoooo
2.代码创建
NSString *plistPath = [NSString stringWithFormat:@"%@/Documents/%@", NSHomeDirectory(), @"test.plist"];
数据写入
NSMutableDictionary *dic = [NSMutableDictionary dictionary];
[dic setObject:@"ceshi"
forKey:@"name"];
[dic setObject:@"12"
forKey:@"age"];
[dic setObject:@"man"
forKey:@"sex"];
[dic writeToFile:plistPath
atomically:YES];
读取
1.手动创建的读取方式
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"download"
ofType:@"plist"];
NSMutableArray *dataArr = [[NSMutableArray alloc] initWithContentsOfFile:filePath];
2.代码创建的读取方式，依然通过路径获取
NSString *plistPath = [NSString stringWithFormat:@"%@/Documents/%@", NSHomeDirectory(), @"test.plist"];
// NSMutableArray *data = [[NSMutableArray alloc] initWithContentsOfFile:plistPath];
NSMutableDictionary *data = [[NSMutableDictionary alloc] initWithContentsOfFile:plistPath];
NSLog(@"%@",data);
打印结果：
2017-06-01 11:32:28.126 AYDataBaseDemo[1989:518382] {
age = 12;
name = zhangsan1111;
sex = man;
}
root 层是什么类型，就用什么类型来解析。
删除 plist 文件
NSFileManager *fileMger = [NSFileManager defaultManager];
NSString *filePath = [NSString stringWithFormat:@"%@/Documents/%@", NSHomeDirectory(), @"test.plist"];
NSLog(@"%@",filePath);
if ([fileMger fileExistsAtPath:filePath]) {// 如果存在就删除
NSError *err;
[fileMger removeItemAtPath:filePath
error:&err];
}
修改，删除，覆盖
新建一个数组写入之前的路径，再次打印发现数据已经被覆盖。
NSMutableArray *arr = [NSMutableArray array];
[arr addObject:@"1"];
[arr addObject:@"2"];
[arr addObject:@"3"];
[arr writeToFile:plistPath
atomically:YES];
NSMutableArray *arrRead = [[NSMutableArray alloc] initWithContentsOfFile:plistPath];
NSLog(@"%@",arrRead);
打印结果：可以发现数据已经变成了 1 2 3
2017-06-01 14:23:17.545 AYDataBaseDemo[2595:818062] {
age = 12;
name = ceshi;
sex = man;
}
2017-06-01 14:23:17.546 AYDataBaseDemo[2595:818062] (
1,
2,
3
)
所以 plist 文件的修改和删除单条数据其实是先 读取 copy 原数据，修改后整体重新覆盖写入，并不是之前期待的类似关系型数据库的操作，但是存一些简单的用户信息，基本设置还是很适合的，毕竟杀鸡焉用宰牛刀~
判断路径下指定文件是否存在
if ([[NSFileManager defaultManager] fileExistsAtPath:plistPath]) {
NSLog(@"exist!");
}
NSUserDefaults 系统封装了一个单例的类，方便使用
系统提供了单例的初始化方式
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
简单写入数据，强制同步 synchronize 并非必要
[defaults setObject:@"barney"
forKey:@"firstName"];
[defaults setInteger:18
forKey:@"Age"];
[defaults synchronize];
读取
NSString *firstName = [defaults objectForKey:@"firstName"];
NSInteger age = [defaults integerForKey:@"Age"];
NSLog(@"firstName = %@,age = %ld",firstName,(long)age);
还可以利用归档存储自定义 model
在 model 类实现 NSCoding 协议
@interface OneModel : NSObject <NSCoding>
@property (nonatomic, copy) NSString *addid;
@property (nonatomic, copy) NSString *age;
@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *salary;
@end
@implementation OneModel
- (void)encodeWithCoder:(NSCoder *)aCoder {
[aCoder encodeObject:self.addid
forKey:@"addid"];
[aCoder encodeObject:self.age
forKey:@"age"];
[aCoder encodeObject:self.name
forKey:@"name"];
[aCoder encodeObject:self.salary
forKey:@"salary"];
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
if (self = [super init]) {
self.addid = [aDecoder decodeObjectForKey:@"addid"];
self.age = [aDecoder decodeObjectForKey:@"age"];
self.name = [aDecoder decodeObjectForKey:@"name"];
self.salary = [aDecoder decodeObjectForKey:@"salary"];
}
return self;
}
@end
model 类声明并且赋值
OneModel *model = [[OneModel alloc] init];
[model setAddid:@"1"];
[model setName:@"barney"];
[model setAge:@"18"];
[model setSalary:@"1000"];
转换 model 类为 data 类型
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:model];
[defaults setObject:data forKey:@"model"];
获取 data 还原回 model
NSData *getData = [defaults objectForKey:@"model"];
OneModel *getModel = [NSKeyedUnarchiver unarchiveObjectWithData:getData];
NSLog(@"addid = %@ name = %@ age = %@ salary = %@",getModel.addid,getModel.name,getModel.age,getModel.salary);
成功打印
2017-06-01 15:49:52.534 AYDataBaseDemo[3040:1210973] addid = 1 name = barney age = 18 salary = 1000
这种数据持久化的方式用在小小的项目上还好，稍大稍复杂的项目通常会使用 SQLite 。或者是 CoreData。
