由于蘋(píng)果最近有了一些新動(dòng)作，所以keychain這個(gè)功能可能沒(méi)有辦法做到iOS刪除App也無(wú)法刪除的數(shù)據(jù)脯燃，具體的內(nèi)容可以看我最新的文章iOS 10.3 keychain 功能可能出現(xiàn)重大更改搂妻。
看標(biāo)題是不是聽(tīng)起來(lái)挺唬人的，沒(méi)錯(cuò)就是這么唬人辕棚，之前我沒(méi)有發(fā)現(xiàn)iOS有這個(gè)功能欲主，但是裝了幾個(gè)百度的應(yīng)用之后我發(fā)現(xiàn)：卸載百度的應(yīng)用之后，過(guò)段時(shí)間再次安裝的時(shí)候你就會(huì)發(fā)現(xiàn)百度賬號(hào)自動(dòng)登錄了逝嚎，沒(méi)錯(cuò)你可以去試試扁瓢。看到這個(gè)現(xiàn)象之后我就尋求實(shí)現(xiàn)方法补君。下面貼出來(lái)：
iOS的keychain服務(wù)提供了一種安全的保存私密信息（密碼引几，序列號(hào)，證書(shū)等）的方式挽铁。每個(gè)ios程序都有一個(gè)獨(dú)立的keychain存儲(chǔ)伟桅。從ios 3.0開(kāi)始，跨程序分享keychain變得可行叽掘。
下面就使用keychain來(lái)實(shí)現(xiàn)存取用戶(hù)名和密碼楣铁。
蘋(píng)果已經(jīng)有現(xiàn)成的類(lèi)封裝好了keychain,KeychainItemWrapper.h和KeychainItemWrapper.m文件,可以在GenericKeychain實(shí)例里找到。
但是這里我只需要存取用戶(hù)名和密碼更扁，就不用蘋(píng)果提供的類(lèi)了盖腕，自己寫(xiě)個(gè)簡(jiǎn)單的類(lèi)來(lái)實(shí)現(xiàn)就好赫冬。
代碼如下：
HPKeychain.h
#import <Foundation/Foundation.h>
@interface HPKeychain : NSObject
+ (void)save:(NSString *)service data:(id)data;
+ (id)load:(NSString *)service;
+ (void)delete:(NSString *)service;
@end
HPKeychain.m
#import "HPKeychain.h"
@implementation HPKeychain
+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
return [NSMutableDictionary dictionaryWithObjectsAndKeys:
(id)kSecClassGenericPassword,(id)kSecClass,
service, (id)kSecAttrService,
service, (id)kSecAttrAccount,
(id)kSecAttrAccessibleAfterFirstUnlock,(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((CFDictionaryRef)keychainQuery);
//Add new object to search dictionary(Attention:the data format)
[keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(id)kSecValueData];
//Add item to keychain with the search dictionary
SecItemAdd((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:(id)kSecReturnData];
[keychainQuery setObject:(id)kSecMatchLimitOne forKey:(id)kSecMatchLimit];
CFDataRef keyData = NULL;
if (SecItemCopyMatching((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((CFDictionaryRef)keychainQuery);
}
@end
使用方法
#import "ViewController.h"
#import "HPKeychain.h"
NSString * const KEY_USERNAME_PASSWORD = @"com.company.app.usernamepassword";
NSString * const KEY_USERNAME = @"com.company.app.username";
NSString * const KEY_PASSWORD = @"com.company.app.password";
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UITextField *nameTextfield;
@property (weak, nonatomic) IBOutlet UITextField *passwordTextField;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
//從keychain中取出用戶(hù)名和密碼：
NSMutableDictionary *usernamepasswordKVPairs = (NSMutableDictionary *)[HPKeychain load:KEY_USERNAME_PASSWORD];
_nameTextfield.text = [usernamepasswordKVPairs objectForKey:KEY_USERNAME];
_passwordTextField.text = [usernamepasswordKVPairs objectForKey:KEY_PASSWORD];
}
- (IBAction)saveAction:(UIButton *)sender {
//把用戶(hù)名和密碼存入keychain：
NSMutableDictionary *usernamepasswordKVPairs = [NSMutableDictionary dictionary];
[usernamepasswordKVPairs setObject:_nameTextfield.text forKey:KEY_USERNAME];
[usernamepasswordKVPairs setObject:_passwordTextField.text forKey:KEY_PASSWORD];
[HPKeychain save:KEY_USERNAME_PASSWORD data:usernamepasswordKVPairs];
UIAlertController * alert = [UIAlertController alertControllerWithTitle:@"提示" message:@"保存成功" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction * action = [UIAlertAction actionWithTitle:@"我知道了" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
NSLog(@"點(diǎn)擊了確認(rèn)");
}];
[alert addAction:action];
[self presentViewController:alert animated:YES completion:nil];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
刪除一個(gè)keychain item:
[HPKeychain delete:KEY_USERNAME_PASSWORD];
這里可以查看代碼
