无法解析符号'GoogleCloudMessaging'GCM

Question

我正在尝试GCM在我的应用程序中工作(在我们的工作时间更改时或在我们有任何促销活动时通知用户),但Cannot resolve symbol 'GoogleCloudMessaging'在尝试使用Google Cloud Messaging API时我一直收到错误消息.

我正在使用新发布的Android工作室IDE来编写代码.

这是我的GcmBroadcastReciever.java代码:

import android.R;
import android.app.Activity;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class GcmBroadcastReceiver extends BroadcastReceiver 
{
    static final String TAG = "GCMDemo";
    public static final int NOTIFICATION_ID = 1;
    private NotificationManager mNotificationManager;
    Context ctx;
    GoogleCloudMessaging gcm; // I get the error here

    @Override
    public void onReceive(Context context, Intent intent) {
        GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(context); //error
        ctx = context;
        String messageType = gcm.getMessageType(intent); //cannot resolve method here
        if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR.equals(messageType)) { //error
            sendNotification("Send error: " + intent.getExtras().toString());
        } else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED.equals(messageType)) { //error
            sendNotification("Deleted messages on server: " +
                    intent.getExtras().toString());
        } else {
            sendNotification("Received: " + intent.getExtras().toString());
        }
        setResultCode(Activity.RESULT_OK);
    }

    // Put the GCM message into a notification and post it.
    private void sendNotification(String msg) {
        mNotificationManager = (NotificationManager)
                ctx.getSystemService(Context.NOTIFICATION_SERVICE);

        PendingIntent contentIntent = PendingIntent.getActivity(ctx, 0,
                new Intent(ctx, Activity.class), 0);

        Toast.makeText(ctx, msg, Toast.LENGTH_SHORT).show();
    }
}

Answer 1

以下部分将指导您完成设置GCM实施的过程.在开始之前,请务必设置Google Play服务SDK.您需要此SDK才能使用GoogleCloudMessaging方法.严格来说,您绝对需要此API的唯一方法是上游(设备到云)消息传递,但它也提供了建议的简化注册API.

您是否设置了Google Play服务SDK？

你必须 :

1. 安装Google Play服务SDK
2. <android-sdk>/extras/google/google_play_services/libproject/google-play-services_lib/在Android项目中引用库项目.

要安装Google Play服务SDK以进行开发:

 1. Launch the SDK Manager.
     - From Eclipse (with ADT), select Window > Android SDK Manager.
     - On Windows, double-click the SDK Manager.exe file at the root of the Android
       SDK directory.
     - On Mac or Linux, open a terminal and navigate to the tools/ directory in 
       the Android SDK, then execute android sdk.
 2. Install the Google Play services SDK.
    Scroll to the bottom of the package list, expand Extras, select Google Play 
    services, and install it. 
    The Google Play services SDK is saved in your Android SDK environment at
    <android-sdk>/extras/google/google_play_services/.
 3. Install a compatible version of the Google APIs platform. 
    If you want to test your app on the emulator, expand the directory for
    Android 4.2.2 (API 17) or a higher version, select Google APIs, and
    install it. Then create a new AVD with Google APIs as the platform target. 
    Note: Only Android 4.2.2 and higher versions of the Google APIs platform
    include Google Play services.

Answer 2

如果您使用的是Android Studio:

1)下载Google Play SDK(使用SDK Manager):

2)不要忘记单击"使用Gradle文件同步项目"按钮

这对我有用.

Answer 3

如果您使用的是Android Studio,请确保build.gradle您拥有:

dependencies {
    compile 'com.google.android.gms:play-services:7.8.0'
}

然后跑build.

这对我有用.