目前本地存储方式大致有：Sqlite,Coredata,NSUserdefaults。但他们都是在删除APP后就会被删除，如果长期使用存储，可以使用Keychain钥匙串来实现。
#import@interface WJQKeyChain : NSObject
+ (void)save:(NSString *)service data:(id)data;
+ (id)load:(NSString *)service;
+ (void)delete:(NSString *)service;
@end
#import "WJQKeyChain.h"
@implementation WJQKeyChain
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
return [NSMutableDictionary dictionaryWithObjectsAndKeys:
(__bridge id)kSecClassGenericPassword,(__bridge id)kSecClass,
service, (__bridge id)kSecAttrService,
service, (__bridge id)kSecAttrAccount,
(__bridge id)kSecAttrAccessibleAfterFirstUnlock,(__bridge id)kSecAttrAccessible,
nil];
}
+ (void)save:(NSString *)service data:(id)data {
//Get search dictionary
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Delete old item before add new item
SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
//Add new object to search dictionary(Attention:the data format)
[keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge id)kSecValueData];
//Add item to keychain with the search dictionary
SecItemAdd((__bridge CFDictionaryRef)keychainQuery, NULL);
}
+ (id)load:(NSString *)service {
id ret = nil;
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
//Configure the search setting
//Since in our simple case we are expecting only a single attribute to be returned (the password) we can set the attribute kSecReturnData to kCFBooleanTrue
[keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge id)kSecReturnData];
[keychainQuery setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];
CFDataRef keyData = NULL;
if (SecItemCopyMatching((__bridge CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
@try {
ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
} @catch (NSException *e) {
NSLog(@"Unarchive of %@ failed: %@", service, e);
} @finally {
}
}
if (keyData)
CFRelease(keyData);
return ret;
}
+ (void)delete:(NSString *)service {
NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
}
test:
NSDictionary *dic = [WJQKeyChain load:@"testData"];
if (dic)
{
self.title = [dic objectForKey:@"title"];
}
else
{
NSDictionary *parma = @{@"title":@"测试数据"};
[WJQKeyChain save:@"testData" data:parma];
}
