# MQKeychain > 简易Keychain访问控制 ``` static func set(key: String, value: Data?) static func set(key: String, value: String) ``` 设置key, value, String默认使用`.utf8` 若为nil则删除 ``` static func search(key: String) -> Data? static func search(stringKey: String) -> String ``` 获取对应key的值 ``` static func clear() ``` 清空Keychain