Question

我有一个活动，我已经为注册过程放了5个片段。第一个片段有两个编辑文本和一个textview。编辑文本用于名字和姓氏，文本视图将我带到下一个fragment2。当我从frag2返回到frag 1时，那些名字和姓氏值消失了。我尝试使用putString方法在onSavedInstance方法中存储值，并在onCreate方法中检索它，但它没有帮助。这是代码......

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if(savedInstanceState==null){

    }
    else{
        firstName=savedInstanceState.getString("firstname");
        lastName=savedInstanceState.getString("lastname");
        fname.setText(firstName);
        lname.setText(lastName);
    }
}

 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.frag1,container,false);
    fname = (EditText) rootView.findViewById(R.id.si_firstname);
    lname = (EditText) rootView.findViewById(R.id.si_lastname);
    firstName = fname.getText().toString();
    lastName = lname.getText().toString();
    next1 = (TextView) rootView.findViewById(R.id.next1);    


    next1.setOnClickListener(new View.OnClickListener() { //takes to frag2.
        @Override
        public void onClick(View v) {

            if(firstName.isEmpty() || lastName.isEmpty()){
                Toast.makeText(getActivity().getApplicationContext(), "no name", Toast.LENGTH_LONG).show();
            }
            else {

                FragmentManager fragmentManager = getFragmentManager();
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                fragmentTransaction.replace(R.id.fragment_container, secondFragment);
                fragmentTransaction.commit();
            }
        }
    });

    return rootView;
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    outState.putString("firstname", firstName);
    outState.putString("lastname", lastName);
}

Answer 1

而不是

fragmentTransaction.replace(R.id.fragment_container, secondFragment);

使用

fragmentTransaction.add(R.id.fragment_container, secondFragment);

修改

如果这不起作用，那么您必须在交易中使用addToBackstack，这肯定会有效。但是，您还需要覆盖Main活动中的onBackPressed函数和popbackStack以弹出片段，然后返回上一个片段。 This是您需要覆盖它的方式。

Answer 2

您似乎正在使用onCreate中设置的值覆盖您在onCreateView内获得的savedInstance数据。尝试在onCreate中注释掉代码并将onCreateView内的顶行替换为：

View rootView = inflater.inflate(R.layout.frag1,container,false);
fname = (EditText) rootView.findViewById(R.id.si_firstname);
lname = (EditText) rootView.findViewById(R.id.si_lastname);
next1 = (TextView) rootView.findViewById(R.id.next1);

if(savedInstanceState != null){ //the data's on the savedinstance
   firstName = savedInstanceState.getString("firstname");
   lastName = savedInstanceState.getString("lastname");
   //restore the editTexts
   fname.setText(firstName);
   lname.setText(lastName);
}else{
   firstName = fname.getText().toString();
   lastName = lname.getText().toString();

   //whatever you want to do on the first run
   //or if the data's not on the savedInstance
}

//whatever else you want to do on every run

返回时保留片段的EditTexts中的值

2 个答案: