使用 asynctask android 连接到套接字

Question

我正在尝试制作一个启动画面，而我正在尝试通过套接字连接服务器。

我对 Android 业务还很陌生，所以我有可能做错了，反正它不起作用。

public class SplashScreen extends Activity {
private Socket socket; // the socket
private final int port = 1500; // the socket port - 1500
private boolean connectivity=false; // if connected to the socket or not
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_splash_screen);
    this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    ConnectToServer cts= new ConnectToServer();
    cts.execute();}


private class ConnectToServer extends AsyncTask<Void, Void, Void> {

 @Override
 protected Void doInBackground(Void... params) {
     try {
         Log.d("socket", "trying to connect");
         socket = new Socket("10.0.0.11", port);
     } catch (UnknownHostException e1) {
         // TODO Auto-generated catch block
         e1.printStackTrace();
     } catch (IOException e1) {
         // TODO Auto-generated catch block
         e1.printStackTrace();
     }
     if (socket.isConnected())
         connectivity=true;
     return null;
 }}


 protected void onPostExecute() {
// execution of result of Long time consuming operation
 Intent i = new Intent(SplashScreen.this, MainActivity.class);
 i.putExtra("connectivity", connectivity);
 startActivity(i);
 finish();}

Answer 1

天哪！你放错了大括号！！！另外，我建议您将这些属性设置为受保护而不是私有，这是一个很长的故事来解释原因（它是为了防止创建特殊的静态方法来获取您的私有字段。您看不到编译器完成的那个过程）。

public class SplashScreen extends Activity {
    protected Socket socket; // the socket
    protected final int port = 1500; // the socket port - 1500
    protected boolean connectivity=false;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_splash_screen);
    this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    ConnectToServer cts= new ConnectToServer();
    cts.execute();
    }

    private class ConnectToServer extends AsyncTask<Void, Void, Void> {

         @Override
         protected Void doInBackground(Void... params) {

             Log.d("socket", "trying to connect");
             try {
                 socket = new Socket("10.0.0.11", port);
             } catch (UnknownHostException e1) {
                 // TODO Auto-generated catch block
                 e1.printStackTrace();
             } catch (IOException e1) {
                 // TODO Auto-generated catch block
                 e1.printStackTrace();
             }
             if (socket.isConnected())
                 connectivity=true;
             return null;
         } // here u have the second } and you finished the class declaration without the following method which is overriden in activity!!!


          @Override
     protected void onPostExecute(Void result) {
        // execution of result of Long time consuming operation
         Intent i = new Intent(getBaseContext(), PreviewActivity.class);
         i.putExtra("connectivity", connectivity);
         startActivity(i);
         finish();

         }
    }
}