Mudanças de comportamento: apps destinados ao Android 17 ou versões mais recentes

Como nas versões anteriores, o Android 17 inclui mudanças de comportamento que podem afetar seu app. As mudanças de comportamento abaixo se aplicam exclusivamente a apps destinados ao Android 17 ou versões mais recentes. Caso seu app seja direcionado ao Android 17 ou a versões mais recentes, faça modificações para oferecer suporte a esses comportamentos, quando aplicável.

Consulte também a lista de mudanças de comportamento que afetam todos os apps executados no Android 17, independente da targetSdkVersion do app.

Experiência do usuário e interface do sistema

O Android 17 inclui as mudanças a seguir, que têm como objetivo criar uma experiência do usuário mais consistente e intuitiva.

Widget de limite de memória

Beginning with Android 17, the system enforces a strict memory limit on RemoteViews updates for apps targeting Android 17 (API level 37) or higher. When an app passes a RemoteViews object to AppWidgetManager.updateAppWidget, system_server calculates the total memory footprint of all image data across every orientation and size bucket in the payload. If the total memory exceeds the system ceiling (mMaxWidgetBitmapMemory), the system rejects the update and throws an IllegalArgumentException:

java.lang.IllegalArgumentException: RemoteViews for widget update exceeds maximum bitmap memory usage (used: XXXXX, max: YYYYY)

For apps targeting API level 36 or lower, the system logs this memory violation as a warning (Slog.w) without throwing an exception.

How the system calculates the memory ceiling

The system sets the widget bitmap memory budget at 6 * width * height bytes (1.5 * 4 * width * height, equivalent to 1.5 times the size of a full-screen ARGB_8888 buffer) for the active display configuration. Under API level 37 and higher, this calculation includes both of the following:

  • In-memory Bitmap and bitmap-backed Icon objects (Icon.TYPE_BITMAP and Icon.TYPE_ADAPTIVE_BITMAP) stored in RemoteViews.mBitmapCache (such as calls to setImageViewBitmap, Icon.createWithBitmap, Icon.createWithAdaptiveBitmap, or Jetpack Glance ImageProvider(bitmap)). Each unique Bitmap or bitmap-backed Icon instance in mBitmapCache is counted once per RemoteViews hierarchy.
  • URI-backed images (Icon.createWithContentUri, setImageViewUri, or Glance ImageProvider(uri)) don't count toward the RemoteViews IPC byte cap in system_server, but the widget host process decodes the referenced content:// file at full resolution into its own heap. Always write a downsampled image into context.cacheDir before exposing it through a FileProvider URI.

Mitigation steps

To keep your widget updates within the memory ceiling across phones, tablets, and foldables, do the following:

  1. Compute your runtime memory budget from WindowMetrics: On API level 30 and higher, read the active window bounds from WindowManager.currentWindowMetrics.bounds rather than resources.displayMetrics. On multi-resolution devices and foldables, displayMetrics can report inactive display dimensions. Estimate your total widget image budget at 6L * bounds.width() * bounds.height() as shown in the following example:

    private const val FALLBACK_MAX_BYTES = 15_000_000L
    
    fun calculateWidgetMemoryCapBytes(context: Context): Long {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
            val wm = context.getSystemService(WindowManager::class.java)
                ?: return FALLBACK_MAX_BYTES
            val bounds = wm.currentWindowMetrics.bounds
            return 6L * bounds.width().toLong() * bounds.height().toLong()
        }
        val dm = context.resources.displayMetrics
        return 6L * dm.widthPixels.toLong() * dm.heightPixels.toLong()
    }
    
  2. Downsample images to the widget's viewable dimensions and use RGB_565: Decode bitmaps with power-of-two BitmapFactory.Options.inSampleSize values sized to the widget's maximum display dimensions (maxWidthDp by maxHeightDp), and use Bitmap.Config.RGB_565 (2 bytes per pixel) instead of ARGB_8888 (4 bytes per pixel) for opaque photographs and thumbnails.

  3. Hoist bitmap decoding outside provideContent in Jetpack Glance: When using SizeMode.Responsive or SizeMode.Exact, Glance invokes your provideContent lambda once per size bucket. Decode each shared Bitmap once inside provideGlance before calling provideContent so all size buckets reference the same Bitmap instance in RemoteViews.mBitmapCache.

  4. Use full updateAppWidget calls when replacing images: In classic AppWidgetProvider implementations, avoid calling AppWidgetManager.partiallyUpdateAppWidget to swap Bitmap or Icon views. Partial updates merge new actions into the existing RemoteViews tree in system_server without evicting previously cached image actions. Build a complete RemoteViews layout and call updateAppWidget instead.

  5. Provide an error fallback layout: In Jetpack Glance, override onCompositionError to render a zero-bitmap RemoteViews fallback if an update fails.

You can inspect your widget's current serialized bitmap memory usage on a connected device by running the following:

adb shell dumpsys appwidget

Principal recurso

O Android 17 inclui as mudanças abaixo, que modificam ou ampliam vários recursos principais do sistema Android.

Nova implementação sem bloqueio de MessageQueue

从 Android 17 开始,以 Android 17(API 级别 37)或更高版本为目标平台的应用会收到 android.os.MessageQueue 的全新无锁实现。新实现可提升性能并减少丢帧,但可能会破坏反映 MessageQueue 私有字段和方法的客户端。

如需了解详情(包括缓解措施),请参阅 MessageQueue 行为变更指南。

Os campos finais estáticos agora não podem ser modificados

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.

Acessibilidade

O Android 17 faz as mudanças abaixo para melhorar a acessibilidade.

Suporte de acessibilidade para digitação complexa em teclado físico com IME

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.

Privacidade

O Android 17 inclui as mudanças abaixo para melhorar a privacidade do usuário.

ECH (Encrypted Client Hello) ativado

Android 17 introduces platform support for Encrypted Client Hello (ECH), a TLS extension that enhances user privacy by encrypting the Server Name Indication (SNI) in the TLS handshake. This encryption helps prevent network observers from easily identifying the specific domain your app is connecting to.

For apps targeting Android 17 (API level 37) or higher, ECH is used for TLS connections. ECH is active only if the networking library used by the app (for example, HttpEngine, WebView, or OkHttp) has integrated ECH support and the remote server also supports the ECH protocol. If ECH cannot be negotiated, the client sends an ECH extension with randomized contents (a mechanism called ECH GREASE). See RFC 9849 for more details on how ECH GREASE works.

To allow apps to customize this behavior, Android 17 adds a new <domainEncryption> element to the Network Security Configuration file. Developers can use <domainEncryption> within <base-config> or <domain-config> tags to select an ECH mode (for example, "enabled" or "disabled") on a global or per-domain basis.

For more information, see the Encrypted Client Hello documentation.

Permissão de rede local necessária para apps destinados ao Android 17

O Android 17 apresenta a permissão de execução ACCESS_LOCAL_NETWORK para proteger os usuários contra o acesso não autorizado à rede local. Como isso se enquadra no grupo de permissões NEARBY_DEVICES, os usuários que já concederam outras permissões NEARBY_DEVICES não vão receber uma nova solicitação. Esse novo requisito impede que apps mal-intencionados usem o acesso irrestrito à rede local para rastreamento de usuários e técnicas de impressão digital. Ao declarar e solicitar essa permissão, seu app pode descobrir e se conectar a dispositivos na rede de área local (LAN), como dispositivos de casa inteligente ou receptores de transmissão.

Os apps destinados ao Android 17 (nível 37 da API) ou versões mais recentes agora têm duas maneiras de manter a comunicação com dispositivos LAN: adotar seletores de dispositivos mediados pelo sistema e que preservam a privacidade para pular a solicitação de permissão ou solicitar explicitamente essa nova permissão no momento da execução para manter a comunicação com a rede local.

Para mais informações, consulte a documentação sobre permissão de rede local.

Ocultar senhas de dispositivos físicos

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.

Proteção de OTP para mensagens SMS padrão

Beginning with Android 17, Android is extending its SMS OTP protection to apply to standard SMS messages (SMS messages containing an OTP that do not use the WebOTP or SMS Retriever formats). For most apps targeting Android 17 (API level 37) or higher, these SMS messages do not become available until three hours after receipt. This delay is intended to help prevent OTP hijacking. During this three hour delay, the SMS_RECEIVED_ACTION broadcast is withheld and SMS provider database queries are filtered. The SMS message is available to these apps after the delay.

Certain apps such as the default SMS assistant app, connected device companion apps, etc., are exempted from this delay. All apps that rely on reading SMS messages for OTP extraction should transition to using SMS Retriever or SMS User Consent APIs to ensure continued functionality.

Segurança

O Android 17 traz as seguintes melhorias para a segurança de dispositivos e apps.

Segurança de atividades

在 Android 17 中,平台继续向“默认安全”架构转变,引入了一系列旨在缓解高严重性漏洞利用(例如钓鱼式攻击、互动劫持和混淆代理攻击)的增强功能。此次更新要求开发者明确选择启用新的安全标准,以保持应用兼容性并保护用户。

对开发者产生的主要影响包括:

  • BAL 强化和改进的选择启用:我们正在优化后台 activity 启动 (BAL) 限制,将保护范围扩展到 IntentSender。开发者必须停止使用旧版 MODE_BACKGROUND_ACTIVITY_START_ALLOWED 常量。相反,您应该采用精细控制,例如 MODE_BACKGROUND_ACTIVITY_START_ALLOW_IF_VISIBLE,它会将 activity 启动限制在调用应用可见的场景中,从而显著减少攻击面。
  • 采用工具:开发者应利用严格模式和更新后的 lint 检查来识别旧版模式,并确保为未来的目标 SDK 要求做好准备。

Ativar CT por padrão

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 中,CT 可用,但应用必须选择启用。)

DCL nativa mais segura: C

If your app targets Android 17 (API level 37) or higher, the Safer Dynamic Code Loading (DCL) protection introduced in Android 14 for DEX and JAR files now extends to native libraries.

All native files loaded using System.load() must be marked as read-only. Otherwise, the system throws UnsatisfiedLinkError.

We recommend that apps avoid dynamically loading code whenever possible, as doing so greatly increases the risk that an app can be compromised by code injection or code tampering.

Restringir campos de PII na visualização de dados do CP2

对于以 Android 17(API 级别 37)及更高版本为目标平台的应用,Contacts Provider 2 (CP2) 会限制数据视图中包含个人身份信息 (PII) 的某些列。启用此变更后,系统会从数据视图中移除这些列,以加强用户隐私保护。 受限列包括:

使用 ContactsContract.Data 中这些列的应用可以改为通过与 RAW_CONTACT_ID 联接,从 ContactsContract.RawContacts 中提取这些列。

Aplicar verificações rigorosas de SQL no CP2

对于以 Android 17(API 级别 37)及更高版本为目标平台的应用,如果在没有 READ_CONTACTS 权限的情况下访问 ContactsContract.Data 表,Contacts Provider 2 (CP2) 会强制执行严格的 SQL 查询验证。

做出此项更改后,如果应用没有 READ_CONTACTS 权限,则在查询 ContactsContract.Data 表时会设置 StrictColumns 和 StrictGrammar 选项。如果查询使用的模式与这些模式不兼容,则会被拒绝并导致抛出异常。

Inteligência

O Android 17 inclui as seguintes mudanças na inteligência do sistema.

Descontinuação de setContentCaptureEnabled

Content Capture is enabled by default on certain devices to allow on-device AI features to analyze screen contents for intelligent experiences.

Starting in Android 17, the ContentCaptureManager.setContentCaptureEnabled(boolean) API method is deprecated. For apps that target Android 17 (API level 37) or higher, calling setContentCaptureEnabled(false) no longer disables Content Capture.

If your app needs to continue disabling Content Capture or restrict screen contents from being captured by the system, you must transition to using the FLAG_SECURE window layout parameter.

To disable Content Capture, set the FLAG_SECURE flag on your window as shown in the following example:

Kotlin

window.setFlags(
    WindowManager.LayoutParams.FLAG_SECURE,
    WindowManager.LayoutParams.FLAG_SECURE
)

Java

getWindow().setFlags(
    WindowManager.LayoutParams.FLAG_SECURE,
    WindowManager.LayoutParams.FLAG_SECURE
);

For more details, see the WindowManager.LayoutParams.FLAG_SECURE reference documentation.

Mídia

O Android 17 inclui as seguintes mudanças no comportamento de mídia.

Proteção de áudio em segundo plano

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.

Formatos de dispositivo

O Android 17 inclui as mudanças a seguir para melhorar a experiência do usuário em vários tamanhos e formatos de dispositivos.

Mudanças na API Platform para ignorar restrições de orientação, redimensionamento e proporção em telas grandes (sw>=600 dp)

我们在 Android 16 中引入了平台 API 变更,以便针对以 API 级别 36 或更高级别为目标平台的应用,忽略大屏设备(sw >= 600dp)上的屏幕方向、尺寸调整和宽高比限制。开发者可以选择在 SDK 36 中选择退出这些变更,但对于以 Android 17(API 级别 37)或更高版本为目标平台的应用,此选择退出选项将不再可用。

如需了解详情,请参阅系统会忽略对屏幕方向和可调整大小性的限制。

Conectividade

O Android 17 apresenta a mudança abaixo para melhorar a consistência e se alinhar ao comportamento padrão do Java InputStream para soquetes RFCOMM Bluetooth.

Comportamento consistente de read() do BluetoothSocket para RFCOMM

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.