使用 Intent 将数据从 Activity 传递到 Service

Question

如何获取从调用Activity传递的 Android Service中的数据？

Answer 1

有关“如何通过意图从活动向服务发送数据”这一问题的准确答案，您是否必须覆盖接收意图对象的onStartCommand()方法：

当你创建一个Service你应该覆盖onStartCommand()方法，所以如果你仔细查看下面的签名，这是你接收传递给它的intent对象的地方：

  public int onStartCommand(Intent intent, int flags, int startId)

因此，从活动中，您将创建意图对象以启动服务，然后将数据放入意图对象中，例如您希望将UserID从Activity传递到Service ：

 Intent serviceIntent = new Intent(YourService.class.getName())
 serviceIntent.putExtra("UserID", "123456");
 context.startService(serviceIntent);

当服务启动时，它的onStartCommand()方法将被调用，因此在此方法中，您可以从意图对象中检索值 (UserID)，例如

public int onStartCommand (Intent intent, int flags, int startId) {
    String userID = intent.getStringExtra("UserID");
    return START_STICKY;
}

注意：上述答案指定使用getIntent()方法获取 Intent，该方法在服务上下文中不正确

Answer 2

第一个上下文（可以是活动/服务等）

对于 Service，您需要覆盖 onStartCommand 才能直接访问intent ：

Override
public int onStartCommand(Intent intent, int flags, int startId) {

您有几个选择：

1) 使用来自Intent的Bundle ：

Intent mIntent = new Intent(this, Example.class);
Bundle extras = mIntent.getExtras();
extras.putString(key, value);  

2) 创建一个新的 Bundle

Intent mIntent = new Intent(this, Example.class);
Bundle mBundle = new Bundle();
mBundle.extras.putString(key, value);
mIntent.putExtras(mBundle);

3）使用Intent的putExtra()快捷方法

Intent mIntent = new Intent(this, Example.class);
mIntent.putExtra(key, value);

新上下文（可以是活动/服务等）

Intent myIntent = getIntent(); // this getter is just for example purpose, can differ
if (myIntent !=null && myIntent.getExtras()!=null)
     String value = myIntent.getExtras().getString(key);
}

注意： Bundle 对所有原始类型、Parcelables 和 Serializable 都有“get”和“put”方法。 我只是将字符串用于演示目的。

Answer 3

如果您绑定您的服务，您将在onBind(Intent intent)获得 Extra。

活动：

 Intent intent = new Intent(this, LocationService.class);                                                                                     
 intent.putExtra("tour_name", mTourName);                    
 bindService(intent, mServiceConnection, BIND_AUTO_CREATE); 

服务：

@Override
public IBinder onBind(Intent intent) {
    mTourName = intent.getStringExtra("tour_name");
    return mBinder;
}

Answer 4

另一种可能性是使用 intent.getAction：

服务中：

public class SampleService inherits Service{
    static final String ACTION_START = "com.yourcompany.yourapp.SampleService.ACTION_START";
    static final String ACTION_DO_SOMETHING_1 = "com.yourcompany.yourapp.SampleService.DO_SOMETHING_1";
    static final String ACTION_DO_SOMETHING_2 = "com.yourcompany.yourapp.SampleService.DO_SOMETHING_2";
    static final String ACTION_STOP_SERVICE = "com.yourcompany.yourapp.SampleService.STOP_SERVICE";

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        String action = intent.getAction();
        //System.out.println("ACTION: "+action);
        switch (action){
            case ACTION_START:
                startingService(intent.getIntExtra("valueStart",0));
                break;
            case ACTION_DO_SOMETHING_1:
                int value1,value2;
                value1=intent.getIntExtra("value1",0);
                value2=intent.getIntExtra("value2",0);
                doSomething1(value1,value2);
                break;
            case ACTION_DO_SOMETHING_2:
                value1=intent.getIntExtra("value1",0);
                value2=intent.getIntExtra("value2",0);
                doSomething2(value1,value2);
                break;
            case ACTION_STOP_SERVICE:
                stopService();
                break;
        }
        return START_STICKY;
    }

    public void startingService(int value){
        //calling when start
    }

    public void doSomething1(int value1, int value2){
        //...
    }

    public void doSomething2(int value1, int value2){
        //...
    }

    public void stopService(){
        //...destroy/release objects
        stopself();
    }
}

在活动中：

public void startService(int value){
    Intent myIntent = new Intent(SampleService.ACTION_START);
    myIntent.putExtra("valueStart",value);
    startService(myIntent);
}

public void serviceDoSomething1(int value1, int value2){
    Intent myIntent = new Intent(SampleService.ACTION_DO_SOMETHING_1);
    myIntent.putExtra("value1",value1);
    myIntent.putExtra("value2",value2);
    startService(myIntent);
}

public void serviceDoSomething2(int value1, int value2){
    Intent myIntent = new Intent(SampleService.ACTION_DO_SOMETHING_2);
    myIntent.putExtra("value1",value1);
    myIntent.putExtra("value2",value2);
    startService(myIntent);
}

public void endService(){
    Intent myIntent = new Intent(SampleService.STOP_SERVICE);
    startService(myIntent);
}

最后，在清单文件中：

<service android:name=".SampleService">
    <intent-filter>
        <action android:name="com.yourcompany.yourapp.SampleService.ACTION_START"/>
        <action android:name="com.yourcompany.yourapp.SampleService.DO_SOMETHING_1"/>
        <action android:name="com.yourcompany.yourapp.SampleService.DO_SOMETHING_2"/>
        <action android:name="com.yourcompany.yourapp.SampleService.STOP_SERVICE"/>
    </intent-filter>
</service>

Answer 5

活动：

int number = 5;
Intent i = new Intent(this, MyService.class);
i.putExtra("MyNumber", number);
startService(i);

服务：

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    if (intent != null && intent.getExtras() != null){
        int number = intent.getIntExtra("MyNumber", 0);
    }
}

Answer 6

这是一种更好且安全的方式。 像魅力一样工作！

   private void startFloatingWidgetService() {
        startService(new Intent(MainActivity.this,FloatingWidgetService.class)
                .setAction(FloatingWidgetService.ACTION_PLAY));
    }

代替 ：

 private void startFloatingWidgetService() {
        startService(new Intent(FloatingWidgetService.ACTION_PLAY));
    }

因为当您尝试第二个时，您会收到一条错误消息： java.lang.IllegalArgumentException: Service Intent must be explicit: Intent { act=com.floatingwidgetchathead_demo.SampleService.ACTION_START }

那么你的服务是这样的：

static final String ACTION_START = "com.floatingwidgetchathead_demo.SampleService.ACTION_START";
    static final String ACTION_PLAY = "com.floatingwidgetchathead_demo.SampleService.ACTION_PLAY";
    static final String ACTION_PAUSE = "com.floatingwidgetchathead_demo.SampleService.ACTION_PAUSE";
    static final String ACTION_DESTROY = "com.yourcompany.yourapp.SampleService.ACTION_DESTROY";

 @SuppressLint("LogConditional")
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    String action = intent.getAction();
    //System.out.println("ACTION: "+action);
    switch (action){
        case ACTION_START:
            Log.d(TAG, "onStartCommand: "+action);
            break;
        case ACTION_PLAY:
            Log.d(TAG, "onStartCommand: "+action);
           addRemoveView();
           addFloatingWidgetView();
            break;
        case ACTION_PAUSE:
            Log.d(TAG, "onStartCommand: "+action);
            break;
        case ACTION_DESTROY:
            Log.d(TAG, "onStartCommand: "+action);
            break;
    }
    return START_STICKY;

}

Answer 7

将数据从 Activity 传递到 IntentService

这就是我将数据从Activity传递到IntentService 。

我的一个应用程序有这种情况。

MusicActivity ------url(String)------> DownloadSongService

1）发送数据（活动代码）

  Intent intent  = new Intent(MusicActivity.class, DownloadSongService.class);
  String songUrl = "something"; 
  intent.putExtra(YOUR_KEY_SONG_NAME, songUrl);
  startService(intent);

2）获取Service中的数据（IntentService代码）
您可以在onHandleIntent()方法中访问意图

public class DownloadSongService extends IntentService {

    @Override
    protected void onHandleIntent(@Nullable Intent intent) {

        String songUrl = intent.getStringExtra("YOUR_KEY_SONG_NAME");

        //  Download File logic
    
    }

}

Answer 8

服务：startservice 会引起副作用，最好的方法是使用 Messenger 和传递数据。

private CallBackHandler mServiceHandler= new CallBackHandler(this);
private Messenger mServiceMessenger=null;
//flag with which the activity sends the data to service
private static final int DO_SOMETHING=1;

private static class CallBackHandler extends android.os.Handler {

private final WeakReference<Service> mService;

public CallBackHandler(Service service) {
    mService= new WeakReference<Service>(service);
}

public void handleMessage(Message msg) {
    //Log.d("CallBackHandler","Msg::"+msg);
    if(DO_SOMETHING==msg.arg1)
    mSoftKeyService.get().dosomthing()
}
}

活动：从 Intent 获取 Messenger 填充它传递数据并将消息传递回服务

private Messenger mServiceMessenger;
@Override
protected void onCreate(Bundle savedInstanceState) {
mServiceMessenger = (Messenger)extras.getParcelable("myHandler");
}


private void sendDatatoService(String data){
Intent serviceIntent= new 
Intent(BaseActivity.this,Service.class);
Message msg = Message.obtain();
msg.obj =data;
msg.arg1=Service.DO_SOMETHING;
mServiceMessenger.send(msg);
}

Answer 9

如果您正在使用 kotlin，您可以尝试以下代码，

在发送活动中，

  val intent = Intent(context, RecorderService::class.java);
  intent.putExtra("filename", filename);
  context.startService(intent)

在服务中，

override fun onStartCommand(intent: Intent, flags: Int, startId: Int): Int {
    super.onStartCommand(intent, flags, startId)

    if (intent != null && intent.extras != null)
       val filename = intent.getStringExtra("filename")

}