之前一直用NSUserDefaults在登錄的時候來保存用戶名和密碼，現(xiàn)在換成另外一種方式，記錄一下，以免以后用到能夠直接command+v

第一種方法--NSUserDefaults
創(chuàng)建一個繼承NSObject的類，在.h里面添加方法

+(void)saveUserName:(NSString *)userName;//保存用戶名
+(NSString *)getUserName;//獲取用戶名
+(void)savePassWD:(NSString *)passWD;//保存用戶密碼
+(NSString *)passWD;//獲取用戶密碼

在.m里面實現(xiàn)方法

//儲存用戶名
+(void)saveUserName:(NSString *)userName
{
    NSUserDefaults *name = [NSUserDefaults standardUserDefaults];
    [name setObject:userName forKey:@"userName"];
}
+(NSString *)getUserName
{
    NSUserDefaults *name = [NSUserDefaults standardUserDefaults];
    NSString *str = [name objectForKey:@"userName"];
    return str;
}
//儲存用戶密碼
+(void)savePassWD:(NSString *)passWD
{
    NSUserDefaults *passWord = [NSUserDefaults standardUserDefaults];
    [passWord setObject:passWD forKey:@"passWord"];
}
+(NSString *)passWD
{
    NSUserDefaults *passWord = [NSUserDefaults standardUserDefaults];
    NSString *str = [passWord objectForKey:@"passWord"];
    return str;
}

第二種方法--Keychain
創(chuàng)建一個繼承NSObject的類，在.h里面添加方法

導(dǎo)入頭文件 #import <Security/Security.h>
+(void)addKeychainData:(id)data forKey:(NSString *)key;//保存
+(id)getKeychainDataForKey:(NSString *)key;//獲取
+(void)deleteKeychainDataForKey:(NSString *)key;//刪除

在.m里面實現(xiàn)方法

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (__bridge id)kSecClassGenericPassword,(id)kSecClass,// 標(biāo)識符(kSecAttrGeneric通常值位密碼)
            service, (__bridge id)kSecAttrService,// 服務(wù)(kSecAttrService)
            service, (__bridge id)kSecAttrAccount,// 賬戶(kSecAttrAccount)
            (__bridge id)kSecAttrAccessibleAfterFirstUnlock,(__bridge id)kSecAttrAccessible,// kSecAttrAccessiblein變量用來指定這個應(yīng)用何時需要訪問這個數(shù)據(jù)
            nil];
}
/**
 儲存用戶賬號
 */
+(void)addKeychainData:(id)data forKey:(NSString *)key
{
    // 獲取查詢字典
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:key];
    // 在刪除之前先刪除舊數(shù)據(jù)
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
    // 添加新的數(shù)據(jù)到字典
    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge id)kSecValueData];
    // 將數(shù)據(jù)字典添加到鑰匙串
    SecItemAdd((__bridge CFDictionaryRef)keychainQuery, NULL);
    
}
+(id)getKeychainDataForKey:(NSString *)key
{
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:key];
    [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: %@",key,e);
        } @finally {
            
        }
    }
    
    if (keyData) {
        CFRelease(keyData);
    }
    
    return ret;
}
+(void)deleteKeychainDataForKey:(NSString *)key
{
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:key];
    SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
}

以后開發(fā)中用到的小tool，都會依次更新到簡書上，，歡迎大家給出更好的意見！