Android 如何延迟服务连接呼叫

我正在实现

服务

，该服务与服务器建立TCP连接，然后允许客户端通过该连接传递消息。客户端通过

bindService

呼叫连接到服务。因此，在客户端

ServiceConnection

对象中调用了

onServiceConnected

。问题是从

bindService

返回后立即调用了

onServiceConnected

，但此时我的

服务未与服务器建立连接。连接未建立时，我是否可以延迟服务连接上的
调用？如果不可能，请为我的案例提出一些好的模式。谢谢。
您应该按照以下步骤操作：

服务代码：

class MyService implements Service {
    private boolean mIsConnectionEstablished = false;

    // Binder given to clients
    private final IBinder mBinder = new LocalBinder();

    public class LocalBinder extends Binder {
        public MyService getService() {
            // Return this instance of LocalService so clients can call public
            // methods
            return MyService.this;
        }
    }

    public interface OnConnectionEstablishedListener {
        public void onConnectionEstablished();
    }

    private OnConnectionEstablishedListener mListener;

    @Override
    public void onCreate() {
       super.onCreate();

       new Thread( new Runnable() {
           @Override
           void run() {
               //Connect to the server here

               notifyConnectionEstablished();
           }
       }).start();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }

    private void notifyConnectionEstablished() {
        mIsConnectionEstablished = true;

        if(mListener != null) {
            mListener.onConnectionEstablished();
        }
    }


    public void setOnConnectionEstablishedListener(
        OnConnectionEstablishedListener listener) {

        mListener = listener

        // Already connected to server. Notify immediately.
        if(mIsConnectionEstablished) {
            mListener.onConnectionEstablished();
        }
    }
}

活动代码：

class MyActivity extends Activity implements ServiceConnection,
    OnConnectionEstablishedListener {

    private MyService mService;
    private boolean mBound;

    @Override
    public void onCreate() {
       super.onCreate();

       //bind the service here
       Intent intent = new Intent(this, MyService.class);
       bindService(intent, this, BIND_AUTO_CREATE);
    }

    @Override
    public void onServiceConnected(ComponentName className, IBinder service) {
        LocalBinder binder = (LocalBinder) service;
        mService = binder.getService();
        mBound = true;

        mService.setOnConnectionEstablishedListener(this);
    }

    @Override
    public void onServiceDisconnected(ComponentName arg0) {
        mBound = false;
    }

    @Override
    public void onConnectionEstablished() {
        // At this point the service has been bound and connected to the server
        // Do stuff here
        // Note: This method is called from a non-UI thread.
    }
}

您应该按照以下步骤进行操作：

服务代码：

class MyService implements Service {
    private boolean mIsConnectionEstablished = false;

    // Binder given to clients
    private final IBinder mBinder = new LocalBinder();

    public class LocalBinder extends Binder {
        public MyService getService() {
            // Return this instance of LocalService so clients can call public
            // methods
            return MyService.this;
        }
    }

    public interface OnConnectionEstablishedListener {
        public void onConnectionEstablished();
    }

    private OnConnectionEstablishedListener mListener;

    @Override
    public void onCreate() {
       super.onCreate();

       new Thread( new Runnable() {
           @Override
           void run() {
               //Connect to the server here

               notifyConnectionEstablished();
           }
       }).start();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }

    private void notifyConnectionEstablished() {
        mIsConnectionEstablished = true;

        if(mListener != null) {
            mListener.onConnectionEstablished();
        }
    }


    public void setOnConnectionEstablishedListener(
        OnConnectionEstablishedListener listener) {

        mListener = listener

        // Already connected to server. Notify immediately.
        if(mIsConnectionEstablished) {
            mListener.onConnectionEstablished();
        }
    }
}

活动代码：

class MyActivity extends Activity implements ServiceConnection,
    OnConnectionEstablishedListener {

    private MyService mService;
    private boolean mBound;

    @Override
    public void onCreate() {
       super.onCreate();

       //bind the service here
       Intent intent = new Intent(this, MyService.class);
       bindService(intent, this, BIND_AUTO_CREATE);
    }

    @Override
    public void onServiceConnected(ComponentName className, IBinder service) {
        LocalBinder binder = (LocalBinder) service;
        mService = binder.getService();
        mBound = true;

        mService.setOnConnectionEstablishedListener(this);
    }

    @Override
    public void onServiceDisconnected(ComponentName arg0) {
        mBound = false;
    }

    @Override
    public void onConnectionEstablished() {
        // At this point the service has been bound and connected to the server
        // Do stuff here
        // Note: This method is called from a non-UI thread.
    }
}

有两个连接。一个appService，可以而且应该立即连接。另外，服务应该连接到服务器。应该有两个连接。有两个连接。一个appService，可以而且应该立即连接。另外，服务应该连接到服务器。应该有两个连接。您正在服务上保存活动实例。这不是正确的方法。活动比服务更容易死机，所以你可以有一个NPE。如果您在“恢复时”或“活动停止时”删除，则可能是在服务上保存活动实例。这不是正确的方法。活动比服务更容易死机，所以你可以有一个NPE。也许如果你在恢复或停止活动时删除。。。