【Objective-C】请求数据放到Plist文件存到沙盒实现数据缓存

iOS应用数据存储的常用方式主要有:

• XML属性列表（plist）归档

• Preference(偏好设置)

• NSKeyedArchiver归档(NSCoding)

• SQLite3

• Core Data

今天小主教大家最简单的本地存储方式
大体的主要思路是我们通常用AFNetworking网络请求数据(返回结果一般是大字典),我们要在请求成功的Block中把请求回来的数据归档写入PList文件中,再在请求失败的Block里将数据反归档取出,再进行数据解析

第一步:我们要封装归档反归档工具

@interface ZHArchiverTools : NSObject
//归档的工具方法
+ (void)archiverObject:(id)object ByKey:(NSString *)key
              WithPath:(NSString *)path;

+ (id)unarchiverObjectByKey:(NSString *)key
                   WithPath:(NSString *)path;
@end

@implementation ZHArchiverTools
+ (void)archiverObject:(id)object ByKey:(NSString *)key WithPath:(NSString *)path
{
    //初始化存储对象信息的data
    NSMutableData *data = [NSMutableData data];
    //创建归档工具对象
    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
    //开始归档
    [archiver encodeObject:object forKey:key];
    //结束归档
    [archiver finishEncoding];
    //写入本地
    NSString *docPath = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES).lastObject;
    NSString *destPath = [[docPath stringByAppendingPathComponent:@"Caches"] stringByAppendingPathComponent:path];

    [data writeToFile:destPath atomically:YES];
}

+ (id)unarchiverObjectByKey:(NSString *)key WithPath:(NSString *)path
{
    NSString *docPath = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES).lastObject;
    NSString *destPath = [[docPath stringByAppendingPathComponent:@"Caches"] stringByAppendingPathComponent:path];
    NSData *data = [NSData dataWithContentsOfFile:destPath];
    //创建反归档对象
    NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
    //接收反归档得到的对象
    id object = [unarchiver decodeObjectForKey:key];
    return object;
}
@end
(以上归档反归档可以直接封装到网络请求的工具类中,以网址为键)

第二步:

归档存数据

第三步：

反归档取数据

断网打开APP,缓存完成