如何在不丢失导航栏的情况下单击导航抽屉项目上的新活动？

Question

我需要调用Riverfragment.java中的courseprof.java（扩展片段）。我在courseprof.java中有我的硬编码设计，这就是为什么我需要在片段内调用它。我使用意图显示它，它显示类，但导航菜单消失。

Riverfragment.java：

package in.wptrafficanalyzer.navigationdrawerdemo;

    import android.app.Fragment;
    import android.os.Bundle;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;

    public class RiverFragment extends Fragment{


        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {

            // Retrieving the currently selected item number
            int position = getArguments().getInt("position");

            // List of rivers
            String[] rivers = getResources().getStringArray(R.array.rivers);

            // Creating view correspoding to the fragment
            View v = inflater.inflate(R.layout.welcome, container, false);
            if(rivers[position].equals("Courses"))
            {
                Intent intent = new Intent(getActivity(), Courseprof.class);
        startActivity(intent);

        }
    }

Courseprof.java

package in.wptrafficanalyzer.navigationdrawerdemo;

import java.util.ArrayList;
import java.util.Iterator;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import android.widget.TableRow.LayoutParams;

public class Courseprof extends Activity{String data = "";
TableLayout tl;
TableRow tr;
Button btcourse;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.courses);
tl = (TableLayout) findViewById(R.id.maintable);

        final getCoursephp getdb = new getCoursephp();
        new Thread(new Runnable() {
            public void run() {
                data = getdb.getCourseFromDB();
                System.out.println(data);

                runOnUiThread(new Runnable() {

                    @Override
                    public void run() {
                        ArrayList<getCourse> courseusers = parseJSON(data);
                        addData(courseusers);                     
                    }

                });   
            }
        }).start();
    }
    public ArrayList<getCourse> parseJSON(String result) {
        ArrayList<getCourse> courseusers = new ArrayList<getCourse>();
        try {
            JSONArray jArray = new JSONArray(result);
            for (int i = 0; i < jArray.length(); i++) {
                JSONObject json_data = jArray.getJSONObject(i);
                getCourse user = new getCourse();
                user.setRoom(json_data.getInt("rooms_id")); //ipinasa dito
                user.setCourse(json_data.getInt("course_id"));
                user.setSection(json_data.getInt("sections_id"));
                courseusers.add(user);
            }
        } catch (JSONException e) {
            Log.e("log_tag", "Error parsing data " + e.toString());  
        }
        return courseusers;
    }

    @SuppressWarnings({ "rawtypes" })
    public void addData(ArrayList<getCourse> courseusers) {
        for (Iterator i = courseusers.iterator(); i.hasNext();) {
            getCourse p = (getCourse) i.next();
            /** Create a TableRow dynamically **/
            tr = new TableRow(this);
            /** Creating a TextView to add to the row **/
            btcourse=new Button(this);
            btcourse.setText(p.getCourseId()+p.getRoom()+p.getSection());
            btcourse.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
                    LayoutParams.WRAP_CONTENT));
            btcourse.setPadding(5, 5, 5, 5);
            btcourse.setBackgroundColor(Color.parseColor("#D8BFD8"));
            LinearLayout Ll = new LinearLayout(this);
            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT,
                    LayoutParams.WRAP_CONTENT);
            params.setMargins(5, 2, 2, 2);
            //Ll.setPadding(10, 5, 5, 5);
            Ll.addView(btcourse,params);
            tr.addView((View)Ll);

         // Add the TableRow to the TableLayout
            tl.addView(tr, new TableLayout.LayoutParams(
                    LayoutParams.FILL_PARENT,
                    LayoutParams.WRAP_CONTENT));
        }
    }

}

courses.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

   <ScrollView android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:fillViewport="true"
    android:layout_below="@+id/textView1">

        <TableLayout android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:stretchColumns="1,1,1"
            android:id="@+id/maintable" >
        </TableLayout>
    </ScrollView>

</RelativeLayout>