如何宣布 pre API 16 的可访问性？

Question

announceForAccessibility(CharSequence text) 方法已添加到 API 16 中，可让您在需要时触发通知。

我尝试使用可访问性管理器在 api 级别 < 16 中执行相同操作，但似乎 TYPE_ANNOUNCEMENT 也在 API 16

中添加

是否有解决方法或支持方法允许我宣布设备运行 api < 16 的辅助功能？

Answer 1

将此添加为 alanv 的答案，以防答案消失。最初发布 here:

you will need to use a slight workaround and trigger an announcement by sending a VIEW_FOCUSED event on ICS, or use the announceForAccessibility API on JellyBean and above. Which would require the support-v4 library and would look like this:

/** The parent context. Used to obtain string resources. */
private final Context mContext;

/**
 * The accessibility manager for this context. This is used to check the
 * accessibility enabled state, as well as to send raw accessibility events.
 */
private final AccessibilityManager mA11yManager;

/**
 * Generates and dispatches an SDK-specific spoken announcement.
 * <p>
 * For backwards compatibility, we're constructing an event from scratch
 * using the appropriate event type. If your application only targets SDK
 * 16+, you can just call View.announceForAccessibility(CharSequence).
 * </p>
 *
 * @param text The text to announce.
 */
private void announceForAccessibilityCompat(CharSequence text) {
    if (!mA11yManager.isEnabled()) {
        return;
    }

    // Prior to SDK 16, announcements could only be made through FOCUSED
    // events. Jelly Bean (SDK 16) added support for speaking text verbatim
    // using the ANNOUNCEMENT event type.
    final int eventType;
    if (Build.VERSION.SDK_INT < 16) {
        eventType = AccessibilityEvent.TYPE_VIEW_FOCUSED;
    } else {
        eventType = AccessibilityEventCompat.TYPE_ANNOUNCEMENT;
    }

    // Construct an accessibility event with the minimum recommended
    // attributes. An event without a class name or package may be dropped.
    final AccessibilityEvent event = AccessibilityEvent.obtain(eventType);
    event.getText().add(text);
    event.setEnabled(isEnabled());
    event.setClassName(getClass().getName());
    event.setPackageName(mContext.getPackageName());

    // JellyBean MR1 requires a source view to set the window ID.
    final AccessibilityRecordCompat record = new AccessibilityRecordCompat(event);
    record.setSource(this);

    // Sends the event directly through the accessibility manager. If your
    // application only targets SDK 14+, you should just call
    // getParent().requestSendAccessibilityEvent(this, event);
    mA11yManager.sendAccessibilityEvent(event);
}

Answer 2

请避免在应用程序中announceForAccessibility()或发送TYPE_ANNOUNCEMENT，除非您传达的消息对设备的使用至关重要。来自这些事件的语音将不会被打断，并且可能会干扰导航或用户与 TalkBack 的交互。

如何宣布 pre API 16 的可访问性？

How to Announce for Accessibility for pre API 16?

android

accessibility