问如何在Tab中不使用ActvityGroup启动新活动

EN

    public class MainActivity extends TabActivity {
        TabHost tabHost;
        Context context = MainActivity.this;
        Button btnGo;
        TabSpec spec;
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main); 
            btnGo = (Button) findViewById(R.id.btn_GO);     
            tabHost = getTabHost();
            // Android tab
            Intent intentHome = new Intent();
            intentHome.setClass(this, Home.class);
            TabSpec tabSpecHome = tabHost
                    .newTabSpec("Home")
                    .setIndicator("Home",
                            getResources().getDrawable(R.drawable.home))
                    .setContent(intentHome);

            tabHost.addTab(tabSpecHome);

            Intent intentNowReading = new Intent().setClass(this, NowReading.class);
            TabSpec tabSpecNowReading = tabHost
                    .newTabSpec("Now Reading")

                    .setIndicator("Now Reading",
                            getResources().getDrawable(R.drawable.now_reading))
                    .setContent(intentNowReading);
            tabHost.addTab(tabSpecNowReading);

            Intent intentFavourite = new Intent().setClass(this, Favorites.class);
            TabSpec tabSpecFavourite = tabHost
                    .newTabSpec("Favourite")
                    .setIndicator("Favorites",
                            getResources().getDrawable(R.drawable.favorites))
                    .setContent(intentFavourite);
            tabHost.addTab(tabSpecFavourite);

            Intent intentProfile = new Intent().setClass(this, Profile.class);
            TabSpec tabSpecProfile = tabHost
                    .newTabSpec("Profile")
                    .setIndicator("Profile",
                            getResources().getDrawable(R.drawable.profile))
                    .setContent(intentProfile);
            tabHost.addTab(tabSpecProfile);
            tabHost.setCurrentTabByTag("Home");
...}