我今天一整天都在与 Android Wear Message API 作斗争，终于接受了我需要一些帮助。

我的应用非常简单。移动部分由一个 MainActivity(除了显示“Hello world”什么都不做)和一个扩展 WearableListenerService 的服务组成。Wear 部分只是一个带有单个按钮的 MainActivity，并实现 MessageApi。 MessageListener.

想法很简单:按下 Wear 设备上的按钮，它会向移动设备发送消息。当 Mobile 收到消息时，它会显示一个 Toast，其中包含发件人的消息路径(例如 /mobile)。执行此操作后，移动设备应立即使用我的reply() 方法向 Wear 设备发送消息back。然后我想做的就是记录这条消息。

我可以完美地实现第一部分。按下 Button 时，Mobile 会弹出一个 Toast，上面写着“/mobile”。然而，答复似乎只是迷失在以太中。没有错误，但也没有消息。

有人可以帮我理解我做错了什么吗？我在下面粘贴了我的文件。

This是我正在关注的教程。干杯!

穿:MainActivity.java

package org.thecosmicfrog.toastdroidmessageapitutorial;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.support.wearable.view.WatchViewStub;
import android.util.Log;
import android.view.View;

import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.wearable.MessageApi;
import com.google.android.gms.wearable.MessageEvent;
import com.google.android.gms.wearable.Node;
import com.google.android.gms.wearable.NodeApi;
import com.google.android.gms.wearable.Wearable;

import java.util.List;
import java.util.concurrent.TimeUnit;

public class MainActivity extends Activity implements MessageApi.MessageListener {

    private final String LOG_TAG = MainActivity.class.getSimpleName();

    private static final long CONNECTION_TIME_OUT_MS = 100;
    private static final String MOBILE_PATH = "/mobile";

    private GoogleApiClient googleApiClient;
    private String nodeId;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initGoogleApiClient();

        final WatchViewStub stub = (WatchViewStub) findViewById(R.id.watch_view_stub);
        stub.setOnLayoutInflatedListener(new WatchViewStub.OnLayoutInflatedListener() {
            @Override
            public void onLayoutInflated(WatchViewStub stub) {
                initWidgets();
            }
        });
    }

    private void initGoogleApiClient() {
        googleApiClient = getGoogleApiClient(this);
        retrieveDeviceNode();
    }

    private GoogleApiClient getGoogleApiClient(Context context) {
        return new GoogleApiClient.Builder(context)
                .addApi(Wearable.API)
                .build();
    }

    private void retrieveDeviceNode() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                if (googleApiClient != null && !(googleApiClient.isConnected() || googleApiClient.isConnecting()))
                    googleApiClient.blockingConnect(CONNECTION_TIME_OUT_MS, TimeUnit.MILLISECONDS);

                NodeApi.GetConnectedNodesResult result =
                        Wearable.NodeApi.getConnectedNodes(googleApiClient).await();

                List<Node> nodes = result.getNodes();

                if (nodes.size() > 0)
                    nodeId = nodes.get(0).getId();

                Log.v(LOG_TAG, "Node ID of phone: " + nodeId);

                googleApiClient.disconnect();
            }
        }).start();
    }

    private void initWidgets() {
        findViewById(R.id.button_toast).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                sendToast();
            }
        });
    }

    private void sendToast() {
        if (nodeId != null) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    if (googleApiClient != null && !(googleApiClient.isConnected() || googleApiClient.isConnecting()))
                        googleApiClient.blockingConnect(CONNECTION_TIME_OUT_MS, TimeUnit.MILLISECONDS);

                    Wearable.MessageApi.sendMessage(googleApiClient, nodeId, MOBILE_PATH, null).await();
                    googleApiClient.disconnect();
                }
            }).start();
        }
    }

    @Override
    public void onMessageReceived(MessageEvent messageEvent) {
        Log.v(LOG_TAG, "In onMessageReceived()");

        if (messageEvent.getPath().equals("/wear")) {
            Log.v(LOG_TAG, "Success!");
        }
    }
}

移动端:ListenerService.java

package org.thecosmicfrog.toastdroidmessageapitutorial;

import android.util.Log;
import android.widget.Toast;

import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.wearable.MessageEvent;
import com.google.android.gms.wearable.Wearable;
import com.google.android.gms.wearable.WearableListenerService;

import java.util.concurrent.TimeUnit;

public class ListenerService extends WearableListenerService {

    private final String LOG_TAG = ListenerService.class.getSimpleName();

    private static GoogleApiClient googleApiClient;

    private static final long CONNECTION_TIME_OUT_MS = 100;
    private static final String WEAR_PATH = "/wear";
    private String nodeId;

    @Override
    public void onMessageReceived(MessageEvent messageEvent) {
        if (messageEvent.getPath().equals("/mobile")) {
            nodeId = messageEvent.getSourceNodeId();
            Log.v(LOG_TAG, "Node ID of watch: " + nodeId);
            showToast(messageEvent.getPath());

            reply(WEAR_PATH);
        }
    }

    private void showToast(String message) {
        Toast.makeText(this, message, Toast.LENGTH_LONG).show();
    }

    private void reply(final String path) {
        googleApiClient = new GoogleApiClient.Builder(getApplicationContext())
                .addApi(Wearable.API)
                .build();

        Log.v(LOG_TAG, "In reply()");
        Log.v(LOG_TAG, "Path: " + path);

        if (googleApiClient != null && !(googleApiClient.isConnected() || googleApiClient.isConnecting()))
            googleApiClient.blockingConnect(CONNECTION_TIME_OUT_MS, TimeUnit.MILLISECONDS);

        Wearable.MessageApi.sendMessage(googleApiClient, nodeId, path, null).await();
        googleApiClient.disconnect();
    }
}

Mobile MainActivity 非常微不足道，因此为了清楚起见，我将其省略。

最佳答案

你永远不会调用 MessageApi.addListener()在您的 Wear Activity 中，因此您的 MessageListener 永远不会注册接收消息。您还应该调用 MessageApi.removeListener()当您的 Activity 被销毁时。

注意:这两种方法都需要连接 GoogleApiClient。如果您在整个 Activity 期间保持 GoogleApiClient 打开而不是尝试在 onDestroy()<>removeListener()/disconnect，这可能会使逻辑更容易.

关于java - 从可穿戴设备发送消息到手机，然后立即回复，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27911579/