行为变更:以 Android 17 或更高版本为目标平台的应用

与之前的版本一样,Android 17 包含一些可能会影响应用的行为变更。以下行为变更仅影响以 Android 17 或更高版本为目标平台的应用。如果您的应用以 Android 17 或更高版本为目标平台,您应该修改自己的应用以支持这些行为(如果适用)。

无论应用的 targetSdkVersion 为何,都请务必查看对 Android 17 上运行的所有应用都有影响的行为变更列表。

核心功能

Android 17 包含以下变更,这些变更会修改或扩展 Android 系统的各种核心功能。

MessageQueue 的新无锁实现

Beginning with Android 17, apps targeting Android 17 (API level 37) or higher receive a new lock-free implementation of android.os.MessageQueue. The new implementation improves performance and reduces missed frames, but may break clients that reflect on MessageQueue private fields and methods.

For more information, including mitigation strategies, see MessageQueue behavior change guidance.

静态 final 字段现在不可修改

Apps running on Android 17 or higher that target Android 17 (API level 37) or higher cannot change static final fields. If an app attempts to change a static final field by using reflection, it will cause an IllegalAccessException. Attempting to modify one of these fields through JNI APIs (such as SetStaticLongField()) will cause the app to crash.

无障碍

Android 17 进行了以下变更,以改进无障碍功能。

复杂 IME 实体键盘输入的无障碍支持

This feature introduces new AccessibilityEvent and TextAttribute APIs to enhance screen reader spoken feedback for CJKV language input. CJKV IME apps can now signal whether a text conversion candidate has been selected during text composition. Apps with edit fields can specify text change types when sending text changed accessibility events. For example, apps can specify that a text change occurred during text composition, or that a text change resulted from a commit. Doing this enables accessibility services such as screen readers to deliver more precise feedback based on the nature of the text modification.

App adoption

  • IME Apps: When setting composing text in edit fields, IMEs can use TextAttribute.Builder.setTextSuggestionSelected() to indicate whether a specific conversion candidate was selected.

  • Apps with Edit Fields: Apps that maintain a custom InputConnection can retrieve candidate selection data by calling TextAttribute.isTextSuggestionSelected(). These apps should then call AccessibilityEvent.setTextChangeTypes() when dispatching TYPE_VIEW_TEXT_CHANGED events. Apps targeting Android 17 (API level 37) that use the standard TextView will have this feature enabled by default. (That is, TextView will handle retrieving data from the IME and setting text change types when sending events to accessibility services).

  • Accessibility Services: Accessibility services that process TYPE_VIEW_TEXT_CHANGED events can call AccessibilityEvent.getTextChangeTypes() to identify the nature of the modification and adjust their feedback strategies accordingly.

隐私权

Android 17 包含以下变更,旨在提升用户隐私保护。

已启用 ECH(加密客户端 Hello)

Android 17 引入了对加密客户端问候 (ECH) 的平台支持。ECH 是一种 TLS 扩展,可通过加密 TLS 握手中的服务器名称指示 (SNI) 来增强用户隐私保护。这种加密有助于防止网络观察者轻松识别您的应用所连接的特定网域。

对于以 Android 17(API 级别 37)或更高版本为目标平台的应用,ECH 用于 TLS 连接。只有当应用使用的网络库(例如 HttpEngine、WebView 或 OkHttp)已集成 ECH 支持,并且远程服务器也支持 ECH 协议时,ECH 才会处于活跃状态。如果无法协商 ECH,客户端会发送一个包含随机内容的 ECH 扩展(一种称为 ECH GREASE 的机制)。如需详细了解 ECH GREASE 的工作原理,请参阅 RFC 9849

为了让应用能够自定义此行为,Android 17 向网络安全配置文件添加了一个新的 <domainEncryption> 元素。 开发者可以在 <base-config><domain-config> 标记中使用 <domainEncryption>,以全局或按网域的方式选择 ECH 模式(例如 "enabled""disabled")。

如需了解详情,请参阅加密客户端问候文档。

以 Android 17 为目标平台的应用需要本地网络权限

Android 17 introduces the ACCESS_LOCAL_NETWORK runtime permission to protect users from unauthorized local network access. Because this falls under the existing NEARBY_DEVICES permission group, users who have already granted other NEARBY_DEVICES permissions aren't prompted again. This new requirement prevents malicious apps from exploiting unrestricted local network access for covert user tracking and fingerprinting. By declaring and requesting this permission, your app can discover and connect to devices on the local area network (LAN), such as smart home devices or casting receivers.

Apps targeting Android 17 (API level 37) or higher now have two paths to maintain communication with LAN devices: Adopt system-mediated, privacy-preserving device pickers to skip the permission prompt, or explicitly request this new permission at runtime to maintain local network communication.

For more information, see the Local network permission documentation.

在实体设备上隐藏密码

If an app targets Android 17 (API level 37) or higher and the user is using a physical input device (for example, an external keyboard), the Android operating system applies the new show_passwords_physical setting to all characters in the password field. By default, that setting hides all password characters.

The Android system shows the last-typed password character to help the user see if they mistyped the password. However, this is much less necessary with larger external keyboards. In addition, devices with external keyboards often have larger displays, which increases the danger of someone seeing the typed password.

If the user is using the device's touchscreen, the system applies the new show_passwords_touch setting.

针对标准短信的 OTP 保护

从 Android 17 开始,Android 将扩展其短信验证码保护功能,以适用于标准短信(包含验证码但不使用 WebOTP 或 SMS Retriever 格式的短信)。对于以 Android 17(API 级别 37)或更高版本为目标平台的应用,这些短信在收到后三小时内不会提供。此延迟旨在帮助防止动态密码劫持。在这三小时的延迟期间,系统会保留 SMS_RECEIVED_ACTION广播,并过滤 短信提供商数据库查询。延迟结束后,这些应用即可使用短信。

某些应用(例如默认短信助理应用、已连接的设备配套应用等)不受此延迟限制。所有依赖于读取短信 来提取动态密码的应用都应改用 SMS RetrieverSMS User Consent API,以确保功能持续可用。

安全

Android 17 对设备和应用安全性进行了以下改进。

活动安全性

In Android 17, the platform continues its shift toward a "secure-by-default" architecture, introducing a suite of enhancements designed to mitigate high-severity exploits such as phishing, interaction hijacking, and confused deputy attacks. This update requires developers to explicitly opt in to new security standards to maintain app compatibility and user protection.

Key impacts for developers include:

  • BAL hardening & improved opt-in: We are refining Background Activity Launch (BAL) restrictions by extending protections to IntentSender. Developers must migrate away from the legacy MODE_BACKGROUND_ACTIVITY_START_ALLOWED constant. Instead, you should adopt granular controls like MODE_BACKGROUND_ACTIVITY_START_ALLOW_IF_VISIBLE, which restricts activity starts to scenarios where the calling app is visible, significantly reducing the attack surface.
  • Adoption tools: Developers should utilize strict mode and updated lint checks to identify legacy patterns and ensure readiness for future target SDK requirements.

默认启用 CT

如果应用以 Android 17(API 级别 37)或更高版本为目标平台,则默认启用证书透明度 (CT)。(在 Android 16 上,CT 可用,但应用必须选择启用。)

更安全的原生 DCL - C

如果您的应用以 Android 17(API 级别 37)或更高版本为目标平台,则 Android 14 中针对 DEX 和 JAR 文件引入的更安全的动态代码加载 (DCL) 保护功能现在也适用于原生库。

使用 System.load() 加载的所有原生文件都必须标记为只读。否则,系统会抛出 UnsatisfiedLinkError

我们建议应用尽可能避免动态加载代码,因为这样做会大大增加应用因代码注入或代码篡改而遭到入侵的风险。

限制 CP2 数据视图中的 PII 字段

For apps targeting Android 17 (API level Android 17 (API level 37)) and higher, Contacts Provider 2 (CP2) restricts certain columns containing Personally Identifiable Information (PII) from the data view. When this change is enabled, these columns are removed from the data view to enhance user privacy. The restricted columns include:

Apps that are using these columns from ContactsContract.Data can extract them from ContactsContract.RawContacts instead, by joining with RAW_CONTACT_ID.

在 CP2 中强制执行严格的 SQL 检查

For apps targeting Android 17 (API level Android 17 (API level 37)) and higher, Contacts Provider 2 (CP2) enforces strict SQL query validation when the ContactsContract.Data table is accessed without READ_CONTACTS permission.

With this change, if an app doesn't have READ_CONTACTS permission, StrictColumns and StrictGrammar options are set when querying the ContactsContract.Data table. If a query uses a pattern that isn't compatible with these, it will be rejected and cause an exception to be thrown.

媒体

Android 17 针对媒体行为做了以下更改。

后台音频安全加固

Beginning with Android 17, the audio framework enforces restrictions on background audio interactions including audio playback, audio focus requests, and volume change APIs to ensure that these changes are started intentionally by the user.

Some audio restrictions apply to all apps. However, the restrictions are more stringent if an app targets Android 17 (API level 37). If one of these apps interacts with audio while it is in the background, it must have a foreground service running. In addition, the app must meet one or both of these requirements:

  • The foreground service must have while-in-use (WIU) capabilities.
  • The app must have the exact alarm permission and be interacting with USAGE_ALARM audio streams.

For more information, including mitigation strategies, see Background audio hardening.

设备规格

Android 17 包含以下变更,可改善各种尺寸和外形规格的设备上的用户体验。

平台 API 变更,用于忽略大屏设备 (sw>=600dp) 上的屏幕方向、尺寸调整能力和宽高比限制

We introduced Platform API changes in Android 16 to ignore orientation, aspect ratio, and resizability restrictions on large screens (sw >= 600dp) for apps targeting API level 36 or higher. Developers have the option to opt out of these changes with SDK 36, but this opt-out will no longer be available for apps that target Android 17 (API level 37) or higher.

For more information, see Restrictions on orientation and resizability are ignored.

连接

Android 17 引入了以下变更,以提高一致性并与蓝牙 RFCOMM 套接字的标准 Java InputStream 行为保持一致。

针对 RFCOMM 的一致 BluetoothSocket read() 行为

For apps targeting Android 17 (API level 37), the read() method of the InputStream obtained from an RFCOMM-based BluetoothSocket now returns -1 when the socket is closed or the connection is dropped.

This change makes RFCOMM socket behavior consistent with LE CoC sockets and aligns with the standard InputStream.read() documentation, which states that -1 is returned when the end of the stream is reached.

Apps that rely solely on catching an IOException to break out of a read loop may be impacted by this change and should update the BluetoothSocket read loops to explicitly check for a return value of -1. This ensures the loop terminates correctly when the remote device disconnects or the socket is closed. For an example of the recommended implementation, see the code snippet in the Transfer Bluetooth data guide.