Thay đổi về hành vi: Ứng dụng nhắm đến Android 17 trở lên

Giống như các bản phát hành trước, Android 17 có các thay đổi về hành vi có thể ảnh hưởng đến ứng dụng của bạn. Những thay đổi về hành vi sau đây chỉ áp dụng cho ứng dụng nhắm đến Android 17 trở lên. Nếu ứng dụng của bạn nhắm đến Android 17 trở lên, bạn nên điều chỉnh ứng dụng để hỗ trợ những hành vi này (nếu cần).

Ngoài ra, hãy nhớ tham khảo danh sách thay đổi về hành vi ảnh hưởng đến tất cả ứng dụng chạy trên Android 17 bất kể targetSdkVersion của ứng dụng.

Lưu ý: Trang này liệt kê một số thay đổi quan trọng hơn. Để biết thêm thông tin chi tiết, hãy xem ghi chú phát hành của Android 17.

Trải nghiệm người dùng và giao diện người dùng hệ thống

Android 17 có những thay đổi sau đây nhằm mang lại trải nghiệm người dùng nhất quán và trực quan hơn.

Tiện ích giới hạn bộ nhớ

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

Chức năng cốt lõi

Android 17 có những thay đổi sau đây nhằm sửa đổi hoặc mở rộng nhiều chức năng cốt lõi của hệ thống Android.

Cách triển khai MessageQueue mới không cần khoá

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.

Các trường cuối cùng tĩnh hiện không thể sửa đổi

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.

Hỗ trợ tiếp cận

Android 17 có những thay đổi sau đây để cải thiện khả năng hỗ trợ tiếp cận.

Hỗ trợ tiếp cận cho thao tác nhập phức tạp bằng bàn phím vật lý 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.

Quyền riêng tư

Android 17 có những thay đổi sau đây để cải thiện quyền riêng tư của người dùng.

Đã bật ECH (Encrypted Client Hello)

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.

Cần có quyền truy cập vào mạng cục bộ đối với các ứng dụng nhắm đến Android 17

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.

Note: In Android 16, apps could opt in to local network permissions. Beginning with Android 17, enforcement is mandatory for apps that target Android 17 (API level 37) or higher.

Ẩn mật khẩu khỏi thiết bị thực

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.

Bảo vệ OTP cho tin nhắn SMS thông thường

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.

Note: Additional SMS OTP protections for WebOTP and SMS Retriever format messages apply to all apps, regardless of their target API level. For more information, see SMS OTP protection in the Behavior changes for all apps documentation.

Bảo mật

Android 17 mang đến những điểm cải tiến sau đây về khả năng bảo mật của thiết bị và ứng dụng.

Bảo mật hoạt động

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.

Bật CT theo mặc định

If an app targets Android 17 (API level 37) or higher, certificate transparency (CT) is enabled by default. (On Android 16, CT is available but apps had to opt in.)

Safer Native DCL – 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.

Hạn chế các trường thông tin nhận dạng cá nhân (PII) trong chế độ xem dữ liệu CP2

Đối với các ứng dụng nhắm đến Android 17 (cấp độ API 37) trở lên, Trình cung cấp danh bạ 2 (CP2) sẽ hạn chế một số cột chứa Thông tin nhận dạng cá nhân (PII) trong chế độ xem dữ liệu. Khi thay đổi này được áp dụng, các cột này sẽ bị xoá khỏi chế độ xem dữ liệu để tăng cường quyền riêng tư của người dùng. Các cột bị hạn chế bao gồm:

• ACCOUNT_NAME
• ACCOUNT_TYPE
• ACCOUNT_TYPE_AND_DATA_SET

Các ứng dụng đang sử dụng những cột này từ ContactsContract.Data có thể trích xuất các cột đó từ ContactsContract.RawContacts bằng cách kết hợp với RAW_CONTACT_ID.

Thực thi các quy trình kiểm tra SQL nghiêm ngặt trong CP2

For apps targeting 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.

Phân tích thông tin

Android 17 có những thay đổi sau đây đối với hệ thống thông minh.

Ngừng sử dụng 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.

Nội dung nghe nhìn

Android 17 có những thay đổi sau đây đối với hành vi của nội dung nghe nhìn.

Tăng cường bảo mật âm thanh nền

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.

Kiểu dáng thiết bị

Android 17 có những thay đổi sau đây để cải thiện trải nghiệm người dùng trên nhiều kích thước và kiểu dáng thiết bị.

Các thay đổi về API nền tảng để bỏ qua các quy tắc hạn chế về hướng, khả năng đổi kích thước và tỷ lệ khung hình trên màn hình lớn (sw>=600dp)

We introduced Platform API changes in Android 16 to ignore orientation, resizability, and aspect ratio 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.

Khả năng kết nối

Android 17 ra mắt thay đổi sau đây để cải thiện tính nhất quán và phù hợp với hành vi InputStream chuẩn của Java cho các cổng Bluetooth RFCOMM.

Hành vi read() nhất quán của BluetoothSocket cho 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.