使用 Fence API 更改使用者活動

如果要檢測使用者何時開始或完成諸如步行，執行或 DetectedActivityFence 類的任何其他活動之類的活動，你可以為要檢測的活動建立圍欄 ，並在使用者啟動時收到通知/完成這項活動。通過使用 BroadcastReceiver，你將獲得包含活動的資料的 Intent：

// Your own action filter, like the ones used in the Manifest.
private static final String FENCE_RECEIVER_ACTION = BuildConfig.APPLICATION_ID +
    "FENCE_RECEIVER_ACTION";
private static final String FENCE_KEY = "walkingFenceKey";
private FenceReceiver mFenceReceiver;
private PendingIntent mPendingIntent;

// Make sure to initialize your client as described in the Remarks section.
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // etc.

    // The 0 is a standard Activity request code that can be changed to your needs.
    mPendingIntent = PendingIntent.getBroadcast(this, 0, 
        new Intent(FENCE_RECEIVER_ACTION), 0);
    registerReceiver(mFenceReceiver, new IntentFilter(FENCE_RECEIVER_ACTION));

    // Create the fence.
    AwarenessFence fence = DetectedActivityFence.during(DetectedActivityFence.WALKING);
    // Register the fence to receive callbacks.
    Awareness.FenceApi.updateFences(client, new FenceUpdateRequest.Builder()
        .addFence(FENCE_KEY, fence, mPendingIntent)
        .build())
        .setResultCallback(new ResultCallback<Status>() {
            @Override
            public void onResult(@NonNull Status status) {
                if (status.isSuccess()) {
                    Log.i(FENCE_KEY, "Successfully registered.");
                } else {
                    Log.e(FENCE_KEY, "Could not be registered: " + status);
                }
            }
        });
    }
}

現在，你可以通過 BroadcastReceiver 接收意圖，以便在使用者更改活動時獲得回撥：

public class FenceReceiver extends BroadcastReceiver {

    private static final String TAG = "FenceReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        // Get the fence state
        FenceState fenceState = FenceState.extract(intent);

        switch (fenceState.getCurrentState()) {
            case FenceState.TRUE:
                Log.i(TAG, "User is walking");
                break;
            case FenceState.FALSE:
                Log.i(TAG, "User is not walking");
                break;
            case FenceState.UNKNOWN:
                Log.i(TAG, "User is doing something unknown");
                break;
        }
    }
}