后退按钮（活动）返回片段

Question

我有一个extends FragmentActivity的类

通过以下方式访问片段：

@Override
public Fragment getItem(int arg0) {
    // TODO Auto-generated method stub

    Fragment fragment=null;
    if (arg0 == 0) {
        fragment = new Fragment_01_Rooms();
    }
    if (arg0 == 1) {
        fragment = new Fragment_02_Contacts();
    }

    return fragment;
}

现在调用的Fragment是public class Fragment_02_Contacts extends Fragment

通过以下目的通过意图调用另一个类：

Intent intent = new Intent(getActivity(), ActivityChatPrivate.class);
intent.putExtra("valueCONTACT", contactSelected);
startActivity(intent);

现在，该类具有public class ActivityChatPrivate extends FragmentActivity

在此类上，我试图通过“后退”按钮返回Fragment_02_Contacts 。 我该怎么做

public void onBackPressed(){
    //some_code_here to return back to Fragment_02_Contacts 
}

Answer 1

尝试这个

Intent intent = new Intent(getActivity(), ActivityChatPrivate.class);
intent.putExtra("valueCONTACT", contactSelected);
intent.putExtra("Fragment", "Fragment2");
startActivity(intent);

现在在您的public class ActivityChatPrivate

String returnToFragment = getIntent().getExtras().getString("Fragment");

在您的onBackPressed

switch(returnToFragment){
  case "Fragment2"
  Fragment_02_Contacts fragment2 = new Fragment_02_Contacts(); 
  FragmentTransaction transaction = getFragmentManager().beginTransaction();
  transaction.replace(R.id.fragment_container, newFragment);
  transaction.commit(); 
break;
}