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I am having great difficulty to convert a non static handler into a static handler. I have tried various approaches but every time I end up in doing something messy. In the provided code please correct me how to achieve this. I did tried one example and I had to change most of my variables and functions into static which were referenced from the handler. But still i got additional errors.

public class MainActivity extends Activity implements Runnable {

private TextView textView;
boolean connectionToTupleSpace=false;
private TupleSpace ts = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    textView = (TextView) findViewById(R.id.myText);
    textView.setText("it is testing");
    findViewById(R.id.login_button).setOnClickListener(buttonLogin);
}

public final Button.OnClickListener buttonLogin = new Button.OnClickListener() {
    @Override
    public void onClick(View v) {
        Thread thread = new Thread(MainActivity.this);
        thread.start();
    }
};

@Override
public void run() {
    Looper.prepare();

    try {
        ts = new TupleSpace("192.168.1.100",2525,"Orientation");
        connectionToTupleSpace = true;
    }catch (TupleSpaceException e) {
        connectionToTupleSpace = false;
        e.printStackTrace();
    }
    handler.sendEmptyMessage(0);
}

private Handler handler = new Handler() {

    private Looper myLooper;

    @Override
    public void handleMessage(Message msg) {
        if(connectionToTupleSpace == true)
        {
            Toast.makeText(getBaseContext(), " Tuple Space Server is Connected", Toast.LENGTH_SHORT).show();
            showTuples();
        }
        else
        {
            /*Toast.makeText(getBaseContext(), " No connection to Tuple Space Server", Toast.LENGTH_SHORT).show();*/
            showDialog("Connection", "there is no connection");

        }
        myLooper = Looper.myLooper();
        Looper.loop();
        myLooper.quit();
    }
};

public void showTuples()
{

    Tuple template = new Tuple(String.class, Integer.class);

    Tuple[] returnTuple = null;
    try {
        returnTuple = ts.readAll(template);
    } catch (TupleSpaceException e) {
        e.printStackTrace();
    }

    int num = returnTuple.length;
    if (num == 0)
        System.out.print("No tuples in the space");
    else
        for(int i=0;i<num;i++)
        {
            System.out.print("\nTotal tuples are" + num+"\nYou found " + returnTuple[i]);
            showDialog(returnTuple[i].getField(0).toString(),returnTuple[i].getField(1).toString());

        }
}

private void showDialog(String title, String message)
{
    AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
    builder.setTitle(title);
    builder.setMessage(message);
    builder.setPositiveButton("OK", null);
    builder.show();
}

}

4

1 回答 1

1

就这样做

private Handler handler = new MyHandler(this);

private static class MyHandler extends Handler {
  MainActivity activity;
  public MyHandler(MainActivity activity) {
     this.activity = activity;
  }
  @Override
  public void handleMessage(Message msg) {
     ...
     activity.showTuples();
     ...
  }
}

要在静态类（MyHandler 内部）中使用您的 Activity，您必须将其作为参数传递给构造函数。

编辑：添加了带有 MainActivity 参数的构造函数。

于 2013-08-01T15:15:05.317 回答