java - 切换到横向模式时 android.view.InflateException

Question

我正在尝试制作一个涉及两个主要内容的应用程序，一个用于纵向，另一个用于横向，但是，当我将方向切换为横向时，应用程序崩溃了。纵向和横向有不同的布局，两者之间唯一显着的区别是横向在其布局中多了一个 fragment 。

我想重申，这是我第一次在 android studio 中使用横向模式，所以如果我犯了任何菜鸟错误，我相信你会原谅的。

欢迎任何意见，提前致谢!

设置Fragment.java

package com.example.celebquizapp;

import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.content.SharedPreferences;

import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;

public class SettingsFragment extends Fragment implements View.OnClickListener {

    private SharedPreferences preferences;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View fragment_view = inflater.inflate(R.layout.fragment_settings, container, false);
        preferences = this.getActivity().getSharedPreferences("values", Context.MODE_PRIVATE);
        return fragment_view;
    }

    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        RadioGroup selectionOption = getActivity().findViewById(R.id.selection_option_setting);
        setRadioButtonListener(selectionOption);

    }

    public void onClick(View v) {
        RadioButton button = (RadioButton) v;
        boolean checked = button.isChecked();

        if (checked) {
            int chosenVal = Integer.parseInt(String.valueOf(button.getText()));
            Log.d("RADIOS", "Current value chosen: " + chosenVal);
            preferences.edit().putInt("numofopt", chosenVal).apply();
        }

    }


    public void setRadioButtonListener(RadioGroup radioGroup) {
        for (int i = 0; i < radioGroup.getChildCount(); i++) {
            radioGroup.getChildAt(i).setOnClickListener(this);
        }
    }

    @Override
    public void onStart() {
        super.onStart();
        // Not required to save data in preferences
        // So delete on start up
        preferences.edit().clear().apply();
    }
}

设置Fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context=".SettingsFragment">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/selectionOptionLabel"
        android:textColor="@color/colorBlack"
        android:textSize="20sp"
        android:layout_marginTop="0dp"
        android:padding="10dp"/>

    <RadioGroup
        android:id="@+id/selection_option_setting"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:textSize="20sp"
            android:text="@string/_2"
            android:layout_marginLeft="10dp" />

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:layout_marginLeft="10dp"
            android:textSize="20sp"
            android:text="@string/_3"/>

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:layout_marginLeft="10dp"
            android:textSize="20sp"
            android:text="@string/_4"/>

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:layout_marginLeft="10dp"
            android:textSize="20sp"
            android:text="@string/_5"/>

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:layout_marginLeft="10dp"
            android:textSize="20sp"
            android:text="@string/_6"/>
    </RadioGroup>

</LinearLayout>

错误信息

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.celebquizapp, PID: 11657
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.celebquizapp/com.example.celebquizapp.MainActivity}: android.view.InflateException: Binary XML file line #22 in com.example.celebquizapp:layout/activity_main: Binary XML file line #26 in com.example.celebquizapp:layout/content_main: Error inflating class fragment
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3270)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.ActivityThread.handleRelaunchActivityInner(ActivityThread.java:5279)
        at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:5187)
        at android.app.servertransaction.ActivityRelaunchItem.execute(ActivityRelaunchItem.java:69)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: android.view.InflateException: Binary XML file line #22 in com.example.celebquizapp:layout/activity_main: Binary XML file line #26 in com.example.celebquizapp:layout/content_main: Error inflating class fragment
     Caused by: android.view.InflateException: Binary XML file line #26 in com.example.celebquizapp:layout/content_main: Error inflating class fragment
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.widget.RadioGroup.getChildCount()' on a null object reference
        at com.example.celebquizapp.SettingsFragment.setRadioButtonListener(SettingsFragment.java:50)
        at com.example.celebquizapp.SettingsFragment.onViewCreated(SettingsFragment.java:32)
        at androidx.fragment.app.FragmentManagerImpl.ensureInflatedFragmentView(FragmentManagerImpl.java:1144)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:851)
        at androidx.fragment.app.FragmentManagerImpl.moveToState(FragmentManagerImpl.java:1133)
        at androidx.fragment.app.FragmentManagerImpl.addFragment(FragmentManagerImpl.java:1393)
        at androidx.fragment.app.FragmentManagerImpl.onCreateView(FragmentManagerImpl.java:3205)
        at androidx.fragment.app.FragmentController.onCreateView(FragmentController.java:134)
        at androidx.fragment.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:357)
        at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:336)
        at android.view.LayoutInflater.tryCreateView(LayoutInflater.java:1069)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:997)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:961)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:1123)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1084)
        at android.view.LayoutInflater.parseInclude(LayoutInflater.java:1263)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:1119)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1084)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:682)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:534)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:481)
        at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:555)
        at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:161)
        at com.example.celebquizapp.MainActivity.onCreate(MainActivity.java:18)
        at android.app.Activity.performCreate(Activity.java:7802)
E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:7791)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.ActivityThread.handleRelaunchActivityInner(ActivityThread.java:5279)
        at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:5187)
        at android.app.servertransaction.ActivityRelaunchItem.execute(ActivityRelaunchItem.java:69)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Answer 1

RadioGroup selectionOption = getActivity().findViewById(R.id.selection_option_setting);

应该是

RadioGroup selectionOption = view.findViewById(R.id.selection_option_setting);