iOS 钥匙串写入值会导致错误代码 -34018

iOS 钥匙串是一种安全的存储机制，用于保存应用程序的敏感信息，例如密码、证书、令牌等。然而，有时候在使用钥匙串写入值时，可能会遇到错误代码 -34018。本文将探讨导致这个错误的原因，并提供解决方案。

xml
keychain-access-groups
	$(AppIdentifierPrefix)com.example.app
NSAppTransportSecurity
	

swift
let password = "12345678"
let passwordData = password.data(using: .utf8)
let query: [String: Any] = [
    kSecClass as String: kSecClassGenericPassword,
    kSecAttrService as String: "com.example.app",
    kSecAttrAccount as String: "user",
    kSecValueData as String: passwordData
]
let status = SecItemAdd(query as CFDictionary, nil)
if status != errSecSuccess {
    print("Failed to add item to keychain. Error: \(status)")
}

swift
let query: [String: Any] = [
    kSecClass as String: kSecClassGenericPassword,
    kSecAttrService as String: "com.example.app",
    kSecAttrAccount as String: "user"
]
let status = SecItemDelete(query as CFDictionary)
if status != errSecSuccess {
    print("Failed to delete item from keychain. Error: \(status)")
}