android - 与可穿戴设备交互的服务
android - service for interaction with wearable
我尝试创建一个服务(它扩展了 WearableListenerService),该服务应该使用可穿戴设备发送和接收数据。 但是当我在该服务中创建 GoogleApiClient 对象时,它因 NullPointerException 而失败。
public class MyService extends WearableListenerService{
private GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Wearable.API)
.build();
private final String MESSAGE_PATH = "/message";
private String remoteNodeId;
@Override
public void onMessageReceived(MessageEvent messageEvent) {
Log.d("myMessage",messageEvent.getData());
remoteNodeId = messageEvent.getSourceNodeId();
sendMessage("Content received");
}
public void sendMessage(String message) {
Wearable.MessageApi.sendMessage(mGoogleApiClient,
remoteNodeId,MESSAGE_PATH,message.getBytes());
}
}
每当我尝试 运行 这个程序时,我都会在 mGoogleApiClient
声明部分收到带有 NullPointerException
的错误消息。
在您的 Service
中覆盖 onCreate,并将 mGoogleApiClient
的初始化放在其中
private GoogleApiClient mGoogleApiClient;
public void onCreate() {
super.onCreate();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Wearable.API)
.build();
}
别忘了打电话给mGoogleApiClient.connect();
我尝试创建一个服务(它扩展了 WearableListenerService),该服务应该使用可穿戴设备发送和接收数据。 但是当我在该服务中创建 GoogleApiClient 对象时,它因 NullPointerException 而失败。
public class MyService extends WearableListenerService{
private GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Wearable.API)
.build();
private final String MESSAGE_PATH = "/message";
private String remoteNodeId;
@Override
public void onMessageReceived(MessageEvent messageEvent) {
Log.d("myMessage",messageEvent.getData());
remoteNodeId = messageEvent.getSourceNodeId();
sendMessage("Content received");
}
public void sendMessage(String message) {
Wearable.MessageApi.sendMessage(mGoogleApiClient,
remoteNodeId,MESSAGE_PATH,message.getBytes());
}
}
每当我尝试 运行 这个程序时,我都会在 mGoogleApiClient
声明部分收到带有 NullPointerException
的错误消息。
在您的 Service
中覆盖 onCreate,并将 mGoogleApiClient
的初始化放在其中
private GoogleApiClient mGoogleApiClient;
public void onCreate() {
super.onCreate();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Wearable.API)
.build();
}
别忘了打电话给mGoogleApiClient.connect();