声明的不属于这个 FragmentManager 的目标 Fragment

Question

我有一个简单的设置：

代码：

ActivityHaupt -> FragmentHaupt：

final FragmentHaupt fragment = new FragmentHaupt();
final FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); 
transaction.add(R.id.frameLHaupt, fragment, null);
transaction.disallowAddToBackStack(); 
transaction.commit();

FragmentHaupt -> FragmentViewP：

FragmentViewPfragment2 = new FragmentViewP();
fragment2.setTargetFragment(FragmentHaupt.this, 12); //AppConstant.FRAGMENT_CODE = 12

FragmentManager fragmentManager =  getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.addToBackStack(null);
fragmentTransaction.replace(R.id.frameLHaupt, fragment2);
fragmentTransaction.commit();

FragmentViewP-> FragmentAddDriver:

FragmentAddDriver ldf = new FragmentAddDriver ();
Bundle args = new Bundle();
args.putString("firstname", vName.getText().toString());
args.putString("lastname", nName.getText().toString());
args.putString("drivername", dName.getText().toString());
ldf.setArguments(args);

ldf.setTargetFragment(FragmentHaupt.newInstance("firstP","lastP"), 12); 
FragmentManager fragmentManager =  getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.addToBackStack(null);
fragmentTransaction.replace(R.id.frameLHaupt, ldf);
fragmentTransaction.commit();

当我尝试打开 FragmentAddDriver 活动时，我收到标题中的错误。问题可能是什么？我总是使用相同的 FragmentManager (getActivity().getSupportFragmentManager)？

我错过了什么？

Answer 1

这里有代码：

ldf.setTargetFragment(FragmentHaupt.newInstance("firstP","lastP"), 12); 

您实际上并没有回到 FragmentHaupt。您正在添加它的一个新实例。

要真正返回，您必须在添加标签时设置标签MainActivity

transaction.add(R.id.frameLHaupt, fragment, "FragmentHaupt");

在FragmentViewP 中，您必须使用该标签找到它。

ldf.setTargetFragment(fragmentManager.findFragmentByTag("FragmentHaupt"), 12);

这样你就可以回到那个实例。