java - 重新访问 fragment 后，在 fragment 内设置文本不起作用

Question

我正在开发一个巴士时刻表 android 应用程序。我有三个 fragment 。在第一个 fragment 中，我有两个单选按钮，即 From Malegaon 和 To Malegaon。 (Malegaon 是地名)。

如果我选择 From Malegaon 单选按钮，那么我会将 sourceEditText 的文本设置为 Malegaon。如果我选择 To Malegaon 单选按钮，那么我将 destinationEditText 的文本设置为 Malegaon。

这种情况工作正常，当我第一次访问 fragment 时，但如果我重新访问 fragment ，则 From Malegaon 单选按钮已被选中，sourceEditText 为空白且 destinationEditText 的文本为 Malegaon。

这是我的第一个 fragment 的快照和代码。

选择 Malegaon 单选按钮后。

我只是在改变布局的可见性。 (源编辑文本、目标编辑文本、搜索按钮是一种布局)

OldStandFragment.java

public class OldStandFragment extends Fragment {

public static OldStandFragment fragment ;
private static final String ARG_POSITIONS = "position";
private int positions;
private View myFragmentViewOld;
private LinearLayout fromOldMalegoanView, toOldMalegoanView;
Button selectRouteButton;
public static final String required_dest = "Please Enter Destination";
public static final String required_source = "Please Enter Source";
String language = "";
DbHelper helper;
private String sourceId = "", destinationId = "";
private ArrayList<Route> myArrayList;
private RouteAdapter routeAdapter;
private ListView routeListView;
private EditText sourceEditTextFromMalegoanOld;
private EditText destinationEditTextFromMalegoanOld;
private ImageButton searchFromMalegoanButtonOld;
private EditText sourceEditTextToMalegoanOld;
private EditText destinationEditTextToMalegoanOld;
private ImageButton searchToMalegoanButtonOld;
private RadioButton fromOldMalegoanRadioButton, toOldMalegoanRadioButton;

public OldStandFragment() {
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    positions = getArguments().getInt(ARG_POSITIONS);

}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    myFragmentViewOld = inflater.inflate(R.layout.fragment_old_stand, container, false);

        selectRouteButton = (Button) myFragmentViewOld.findViewById(R.id.selectRouteButton);

        fromOldMalegoanRadioButton = (RadioButton) myFragmentViewOld.findViewById(R.id.fromOldMalegoanRadioButton);
        toOldMalegoanRadioButton = (RadioButton) myFragmentViewOld.findViewById(R.id.toOldMalegoanRadioButton);

        fromOldMalegoanView = (LinearLayout) myFragmentViewOld.findViewById(R.id.fromOldMalegoanView);
        toOldMalegoanView = (LinearLayout) myFragmentViewOld.findViewById(R.id.toOldMalegoanView);

        sourceEditTextFromMalegoanOld = (EditText) fromOldMalegoanView.findViewById(R.id.sourceEditText);
        destinationEditTextFromMalegoanOld = (EditText) fromOldMalegoanView.findViewById(R.id.destinationEditText);
        searchFromMalegoanButtonOld = (ImageButton) fromOldMalegoanView.findViewById(R.id.searchResultButton);

        sourceEditTextToMalegoanOld = (EditText) toOldMalegoanView.findViewById(R.id.sourceEditText);
        destinationEditTextToMalegoanOld = (EditText) toOldMalegoanView.findViewById(R.id.destinationEditText);
        searchToMalegoanButtonOld = (ImageButton) toOldMalegoanView.findViewById(R.id.searchResultButton);

        SharedPreferences prefs = getContext().getSharedPreferences("MyPrefsFile", Context.MODE_PRIVATE);
        int a = prefs.getInt("LangValue", 0);
        if (a == 0) {
            language = "English";
        } else {
            language = "मराठी";
        }

        helper = new DbHelper(getContext());
        fromOldMalegoanRadioButton.setChecked(true);
        toOldMalegoanRadioButton.setChecked(false);
        fromOldMalegoanView.setVisibility(View.VISIBLE);
        toOldMalegoanView.setVisibility(View.GONE);

        String stopValue = helper.getStopName("1", language);
        sourceEditTextFromMalegoanOld.setText(stopValue);

        fromOldMalegoanRadioButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (fromOldMalegoanRadioButton.isChecked()) {

                    toOldMalegoanRadioButton.setChecked(false);
                    fromOldMalegoanView.setVisibility(View.VISIBLE);
                    toOldMalegoanView.setVisibility(View.GONE);

                    helper = new DbHelper(getContext());
                    String stopValue1 = helper.getStopName("1", language);
                    sourceEditTextFromMalegoanOld.setText(stopValue1);
                    destinationEditTextFromMalegoanOld.setText("");
                }
            }
        });

        toOldMalegoanRadioButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (toOldMalegoanRadioButton.isChecked()) {

                    fromOldMalegoanRadioButton.setChecked(false);
                    fromOldMalegoanView.setVisibility(View.GONE);
                    toOldMalegoanView.setVisibility(View.VISIBLE);

                    helper = new DbHelper(getContext());
                    String stopValue2 = helper.getStopName("1", language);
                    destinationEditTextToMalegoanOld.setText(stopValue2);
                    sourceEditTextToMalegoanOld.setText("");
                }
            }
        });

        searchFromMalegoanButtonOld.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               //search result code.
            }
        });

        searchToMalegoanButtonOld.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               //search result code.
            }
        });
    return myFragmentViewOld;
}

public static OldStandFragment newInstance(int position) {
    if(fragment == null) {
        fragment = new OldStandFragment();
    }

    Bundle bundle = new Bundle();
    bundle.putInt(ARG_POSITIONS, position);
    fragment.setArguments(bundle);
    return fragment;
    }
}

fragment_old_stand.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#000000"
android:scrollbars="vertical"
tools:context="com.ashishkudale.malegoanagar.Fragments.OldStandFragment">


<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Select Direction or Route"
                android:gravity="center"
                android:textColor="#FFFFFF"
                android:id="@+id/Note"
                android:textStyle="bold"
                android:textAppearance="?android:attr/textAppearanceMedium"
                android:layout_margin="15dp" />
        </LinearLayout>


        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <RadioGroup
                android:id="@+id/rg_ContainerOld"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:layout_marginTop="15dp">

                <RadioButton
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="From Malegaon"
                    android:id="@+id/fromOldMalegoanRadioButton"
                    android:layout_marginLeft="5dp"
                    android:checked="false" />

                <LinearLayout
                    android:orientation="vertical"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="10dp">

                    <include
                        android:id="@+id/fromOldMalegoanView"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        layout="@layout/source_destination"
                        android:layout_margin="5dp" />

                </LinearLayout>

                <RadioButton
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="To Malegaon"
                    android:id="@+id/toOldMalegoanRadioButton"
                    android:layout_marginLeft="5dp" />

                <LinearLayout
                    android:orientation="vertical"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="10dp">

                    <include
                        android:id="@+id/toOldMalegoanView"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        layout="@layout/source_destination"
                        android:layout_margin="5dp" />

                </LinearLayout>

            </RadioGroup>
        </LinearLayout>

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="  Select Route  "
            android:id="@+id/selectRouteButton"
            android:background="@drawable/button_effect"
            android:layout_gravity="center_horizontal"
            android:layout_margin="5dp" />

    </LinearLayout>

</ScrollView>

这是调用 fragment 的适配器。

MyPagerAdapter

public class MyPagerAdapter extends FragmentPagerAdapter {

    private final String[] TITLES = {"Old Stand","New Stand", "Fare"};

    public MyPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return TITLES[position];
    }

    @Override
    public int getCount() {
        return TITLES.length;
    }

    @Override
    public android.support.v4.app.Fragment getItem(int position) {
        android.support.v4.app.Fragment fragment = null;
        if(position ==0) {
            fragment = OldStandFragment.newInstance(position);
        }else if(position ==1 ){
            fragment = NewStandFragment.newInstance(position);
        } else if (position == 2) {
            fragment = MapFragment.newInstance(position);
        }
        return  fragment;
    }
}

在重新访问 OldStandFragment 之后，它看起来像这样。

我检查了所有可能的添加日志。我发现在重新访问 OldStandFragment 之后，toOldMalegoanRadioButton.setOnClickListner() 方法被调用。

现在我想在重新访问时刷新 fragment 或以任何其他方式解决此问题。

Answer 1

你必须使用 SharedPreferences 来保存复选框的状态，试试这个代码

    public class StackOne extends AppCompatActivity {

    SharedPreferences prefs;
    private RadioButton rButton1, rButton2;
    private RadioGroup rg_ContainerOld;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.stack_one);

        prefs = PreferenceManager.getDefaultSharedPreferences(StackOne.this);

        rButton1 = (RadioButton) findViewById(R.id.fromOldMalegoanRadioButton);
        rButton2 = (RadioButton) findViewById(R.id.toOldMalegoanRadioButton);
        rg_ContainerOld = (RadioGroup) findViewById(R.id.rg_ContainerOld);

        GetSelectedRadioButton();

        int k = prefs.getInt("rb1", 0);
        if (k == 1) {
            rButton1.setChecked(true);
            sourceEditTextFromMalegoanOld.setText("");
        } else if (k == 2) {
            rButton2.setChecked(true);
            sourceEditTextToMalegoanOld.setText("");
        }
    }

    private void GetSelectedRadioButton() {

        rg_ContainerOld.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {

                switch (group.getCheckedRadioButtonId()) {
                    case R.id.fromOldMalegoanRadioButton:
                        prefs.edit().putInt("rb1", 1).commit();
                        break;
                    case R.id.toOldMalegoanRadioButton:
                        prefs.edit().putInt("rb1", 2).commit();
                        break;
                }
            }
        });
    }
}