安卓开发adaper自定义时构造函数能否只有两个参数?

我想问一下为什么这个adapter只有两个参数而且第二个参数是访问数据库之后的结果却可以写呢,难道第二个参数不应该是R.layout.什么的整型参数吗.....因为我在看别人的代码,可是他的项目可能把整个adapter.class给删了...所以不知道源码是什么了,想问一下有没有大佬知道~

部分代码如下

     cursor = ssdb.rawQuery("select _id, stuId, couId, name, grade from grade inner join course" +
                " on grade.couId=course.id where stuId=\"" + stuId + "\";", null);


        if (cursor.moveToFirst()) {
            do {
                String id = cursor.getString(cursor.getColumnIndex("couId"));
                String na = cursor.getString(cursor.getColumnIndex("name"));
                float gr = cursor.getInt(cursor.getColumnIndex("grade"));
                courses.add(new Course(na, id, gr));
            } while (cursor.moveToNext());
        }

        sciAdapter = new StuCourInfoAdapter(this, courses);//实例一个adapter对象

        final ListView listView = (ListView) findViewById(R.id.stu_cou_list);

        listView.setAdapter(sciAdapter);
        listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                Course course = courses.get(position);

                chooseAlert(course, position);
                return true;
            }
        });

    public class StuCourInfoAdapter extends BaseAdapter {
    private  List<Course> mList;
                private  Context mContext
    public StuCourInfoAdapter(Context context, List<Course> list) {
        mList = list;
                    mContext=context;
    }
    @Override
    public int getCount() {
        return mList == null ? 0 : mList.size();
    }
    // @Override
   public Object getItem(int position) {
            return mList.get(position)
  }

@Override
public long getItemId(int position) {
    return  position
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    //r其他操作
}
            }

这都是java的基本功了，构造函数当然可以自己任意定义了，你都new出来了还看不到源码？

    public class StuCourInfoAdapter extends BaseAdapter {
        private final List<Course> mList;
        public StuCourInfoAdapter(Context context, List<Course> list) {
            mList = list;
        }
        @Override
        public int getCount() {
            return mList == null ? 0 : mList.size();
        }
        //...其他操作
    }