How to bind an Activity to a Service and control and manage the Service from the Activity
我正在尝试将 Activity 绑定到 LocalService 以与之交互。但是在我的 Activity 中,我只能调用 LocalBinder 中定义的方法,而不能调用 LocalService 中定义的方法。我做错了什么?
没有从头开始我阅读了另一个问题,并且我已经阅读了一些如何编写一些示例代码的内容,我的代码类似于该示例代码。此外,为了方便起见,我一直在阅读一些服务文档,这里是文档该部分的一小段引述:
"当应用程序组件通过调用 bindService() 绑定到服务时,服务被"绑定"。绑定服务提供客户端-服务器接口,允许组件与服务交互、发送请求、获取结果,甚至执行所以通过进程间通信(IPC)跨进程。绑定的服务只有在另一个应用程序组件绑定到它时才会运行。多个组件可以一次绑定到服务,但是当它们全部解除绑定时,服务就会被销毁。"
但我不能那样做。如上所述,我能做的最好的事情就是在我的 LocalBinder 中定义我的 Activity 调用方法。我没有像上面黑色突出显示的部分那??样取得任何成就。
如果有帮助,这里是我的代码的相关部分。
要绑定的LocalService:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 | /************************************************************************************************** * Filename: LocalService.java * Project name: Local Service Sample * Application name: Local Service * Description: This file contains the LocalService (extends Service) for our Local Service app **************************************************************************************************/ package com.marie.localservicesample; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.UUID; import android.app.Notification; import android.app.NotificationManager; import android.app.PendingIntent; import android.app.Service; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.Intent; import android.os.Bundle; import android.os.IBinder; import android.os.Looper; import android.os.Message; import android.os.Messenger; import android.os.RemoteException; import android.util.Log; import android.widget.Toast; public class LocalService extends Service { private NotificationManager mNM; // Unique Identification Number for the Notification. // We use it on Notification start, and to cancel it. private int NOTIFICATION = R.string.local_service_started; // just some arbitrary numbers for test purposes public static int statusCode = 99; public static int emptyMsg = 549; // I get my Extras from onStartCommand and use in ServiceWorker() thread public static final String EXTRA_MAC ="com.marie.localservicesample.EXTRA_MAC"; private String macString; public static final String EXTRA_MESSENGER ="com.marie.localservicesample.EXTRA_MESSENGER"; private Messenger messenger; private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //private static final String macString ="00:06:66:02:D0:EC"; Boolean stop_receive_data = false; // This is the object that receives interactions from clients. See // RemoteService for a more complete example - or not because // this is a local service private final IBinder mBinder = new LocalBinder(); @Override public IBinder onBind(Intent intent) { Log.i("onBind","called in LocalService" ); Log.i("onBind","intent:" + intent.toString()); Log.i("onBind","mBinder:" + mBinder); return mBinder; } @Override public void onCreate() { mNM = (NotificationManager)getSystemService(NOTIFICATION_SERVICE); // Display a notification about us starting. We put an icon in the status bar. showNotification(); } // Call this at the end of onStartCommand() after we got the Extras public void afterStartCommand() { Thread thr = new Thread(null, new ServiceWorker(),"LocalService"); thr.start(); } /* * This is the ServiceWorker thread that passes messages to the handler defined in * the Controller activity. */ class ServiceWorker implements Runnable { public void run() { // do background processing here... something simple Looper.prepare(); BluetoothAdapter btAdapter = BluetoothAdapter.getDefaultAdapter(); BluetoothDevice btDevice = btAdapter.getRemoteDevice(macString); BluetoothSocket btSocket = null; InputStream btIstream = null; OutputStream btOstream = null; try { btSocket = btDevice.createRfcommSocketToServiceRecord(MY_UUID); } catch (IOException e1) { e1.printStackTrace(); } try { btSocket.connect(); } catch (IOException e1) { e1.printStackTrace(); } try { btIstream = btSocket.getInputStream(); btOstream = btSocket.getOutputStream(); } catch (IOException e1) { e1.printStackTrace(); } try { int data = btIstream.read(); // reset the bluetooth device while (data != 63) { Log.d("LocalService","resetting bluetooth device"); btOstream.write('r'); data = btIstream.read(); } StringBuffer strBuffer = new StringBuffer(""); Boolean dataBegin = false; int ndxPlus = 0; while (data != -1) { char printableB = (char) data; if (data < 32 || data > 126) { //printableB = ' '; } //Log.d("LocalService", Character.toString(printableB) +"(" + data +")"); if (data == 63) { btOstream.write('$'); btOstream.write(','); } if (data == 45) { btOstream.write('1'); btOstream.write(','); dataBegin = true; } if (dataBegin == true) { strBuffer = strBuffer.append(Character.toString(printableB)); } if (data == 13) { dataBegin = false; //Log.d("LocalServiceDataString", strBuffer.toString()); // send data to the handler to plot the data Message msg = Message.obtain(); msg.what = Controller.MESSAGE_MAC; msg.obj = strBuffer; try { messenger.send(msg); } catch (RemoteException e) { e.printStackTrace(); } strBuffer = new StringBuffer(""); if (ndxPlus < 0) { btOstream.write('+'); ndxPlus++; } } data = btIstream.read(); if (stop_receive_data) data = -1; } } catch (IOException e1) { e1.printStackTrace(); } try { btSocket.close(); } catch (IOException e1) { e1.printStackTrace(); } LocalService.this.stopSelf(); Looper.loop(); // stop the service when done... // Or use the unbindBtn in the MainActivity class? } } @Override public int onStartCommand(Intent intent, int flags, int startId) { Log.i("LocalService","Received start id" + startId +":" + intent); Bundle extras = intent.getExtras(); messenger = (Messenger)extras.get(EXTRA_MESSENGER); macString = extras.getString(EXTRA_MAC); afterStartCommand(); // We want this service to continue running until it is explicitly // stopped, so return sticky. return START_STICKY; } @Override public void onDestroy() { // Cancel the persistent notification. mNM.cancel(NOTIFICATION); stop_receive_data = true; // Tell the user we stopped. Toast.makeText(this, R.string.local_service_stopped, Toast.LENGTH_SHORT).show(); } /** * Show a notification while this service is running. */ private void showNotification() { // In this sample, we'll use the same text for the ticker and the expanded notification CharSequence text = getText(R.string.local_service_started); // Set the icon, scrolling text and timestamp Notification notification = new Notification(R.drawable.stat_sample, text, System.currentTimeMillis()); // The PendingIntent to launch our activity if the user selects this notification PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, Controller.class), 0); // Set the info for the views that show in the notification panel. notification.setLatestEventInfo(this, getText(R.string.local_service_label), text, contentIntent); // Send the notification. mNM.notify(NOTIFICATION, notification); } } |
绑定到 LocalService 的活动:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | /************************************************************************************************** * Filename: Binding.java * Project name: Local Service Sample * Application name: Local Service * Description: This file contains the Binding class for our Local Service application **************************************************************************************************/ package com.marie.localservicesample; import android.app.Activity; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.os.Bundle; import android.os.IBinder; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.Toast; /* * Example of binding and unbinding to the local service. * This demonstrates the implementation of a service which the client will * bind to, receiving an object through which it can communicate with the service. */ public class Binding extends Activity { private ILocalBinder mBoundService; private boolean mIsBound; private ServiceConnection mConnection = new ServiceConnection() { public void onServiceConnected(ComponentName className, IBinder service) { // This is called when the connection with the service has been // established, giving us the service object we can use to // interact with the service. Because we have bound to a explicit // service that we know is running in our own process, we can // cast its IBinder to a concrete class and directly access it. mBoundService = (ILocalBinder)service; int statusCode = mBoundService.getStatusCode(); Log.d("Binding.java","called onServiceConnected. statusCode:" + statusCode); Toast.makeText(Binding.this, R.string.local_service_connected, Toast.LENGTH_SHORT).show(); } public void onServiceDisconnected(ComponentName className) { // This is called when the connection with the service has been // unexpectedly disconnected -- that is, its process crashed. // Because it is running in our same process, we should never // see this happen. mBoundService = null; Log.d("Binding","called onServiceDisconnected"); Toast.makeText(Binding.this, R.string.local_service_disconnected, Toast.LENGTH_SHORT).show(); } }; void doBindService() { // Establish a connection with the service. We use an explicit // class name because we want a specific service implementation that // we know will be running in our own process (and thus won't be // supporting component replacement by other applications). bindService(new Intent(Binding.this, LocalService.class), mConnection, Context.BIND_AUTO_CREATE); mIsBound = true; } void doUnbindService() { if (mIsBound) { int statusCode = mBoundService.getStatusCode(); if (statusCode != 0) Log.d("doUnbindService","Binding.java statusCode:" + statusCode); // Tell the user we did an unbind Toast.makeText(this, R.string.local_service_unbound, Toast.LENGTH_SHORT).show(); // Detach our existing connection. unbindService(mConnection); mIsBound = false; } } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.local_service_binding); // Watch for button clicks. Button button = (Button)findViewById(R.id.bind); button.setOnClickListener(mBindListener); button = (Button)findViewById(R.id.unbind); button.setOnClickListener(mUnbindListener); } private OnClickListener mBindListener = new OnClickListener() { public void onClick(View v) { doBindService(); } }; private OnClickListener mUnbindListener = new OnClickListener() { public void onClick(View v) { doUnbindService(); } }; @Override protected void onDestroy() { super.onDestroy(); doUnbindService(); } } |
我的 ILocalBinder 和 LocalBinder:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | /************************************************************************************************** * Filename: ILocalBinder.java * Project name: Local Service Sample * Application name: Local Service * Description: This file contains an example interface for my LocalBinder **************************************************************************************************/ package com.marie.localservicesample; public interface ILocalBinder { public int getStatusCode(); } /************************************************************************************************** * Filename: LocalBinder.java * Project name: Local Service Sample * Application name: Local Service * Description: This file contains the LocalBinder class for our Local Service application **************************************************************************************************/ package com.marie.localservicesample; import android.os.Binder; import com.marie.localservicesample.LocalService; /** * Class for clients to access. Because we know this service always * runs in the same process as its clients, we don't need to deal with * IPC. */ public class LocalBinder extends Binder implements ILocalBinder { @Override public int getStatusCode() { return LocalService.statusCode; } } |
谢谢!
参见本地服务示例。
只需将它们拥有的 binder 类代码复制到您的服务中,而不是为其创建单独的文件:(在 LocalService 类声明中)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | public class LocalService { // This is the object that receives interactions from clients. See // RemoteService for a more complete example. private final IBinder mBinder = new LocalBinder(); /** * Class for clients to access. Because we know this service always * runs in the same process as its clients, we don't need to deal with * IPC. */ public class LocalBinder extends Binder { LocalService getService() { return LocalService.this; } } ... } |
然后:
1 2 3 4 5 6 7 | public void onServiceConnected(ComponentName className, IBinder service) { // This is called when the connection with the service has been // established, giving us the service object we can use to // interact with the service. Because we have bound to a explicit // service that we know is running in our own process, we can // cast its IBinder to a concrete class and directly access it. mBoundService = ((LocalService.LocalBinder)service).getService(); |
现在您可以使用 mBoundService 直接访问您的服务。