java - OnClickListener() 在 Fragment 中崩溃

Question

由于某种原因，当我单击应用程序中的工具栏(工具栏)和 float 按钮(按钮)时，OnClickListener () 方法会使代码 fragment 和应用程序崩溃

虽然 ImageButton(OnOff) 处理程序运行并且不会使 fragment 崩溃

fragment

public class ZnonkiFragment extends Fragment {
    private SharedPreferences settings;
    private ImageButton OnOff;
    private ViewPager viewPager;
    private DrawerLayout drawerLayout;
    private MainActivity.PagerAdapter pagerAdapter;
    private FloatingActionButton button;
    final Context context = getActivity();
    private androidx.appcompat.widget.Toolbar toolbar;
    private TabLayout tabLayout;
    private String ZvonOne, ZvonTwo;
    private List<Fragment> list = new ArrayList<>();
    private String url;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view =  inflater.inflate(R.layout.fragment_znonki, container,
       toolbar =  view.findViewById(R.id.toolbar);
       toolbar.setNavigationIcon(getResources().getDrawable(R.drawable.menu));
       toolbar.setNavigationOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View view) {
               Toast.makeText(context,"lel",Toast.LENGTH_LONG).show();
           }
       });
        //...

       addListenerOnButton(view);
        return view;
    }

    public boolean checkString(String string) {
        try {
            Integer.parseInt(string);
        } catch (Exception e) {
            return false;
        }
        return true;
    }

    public void addListenerOnButton (final View viewOne){
        OnOff = viewOne.findViewById(R.id.onOff);
        button =  viewOne.findViewById(R.id.floatingActionButton);
        OnOff.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               //...
        });
        button.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(final View view) {
                 //...
                });
        button.setOnClickListener(new View.OnClickListener()  {
                    @Override
                    public void onClick(View view) {
                         //...
                      });
    }


}

XML

    <?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".ZnonkiFragment">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme"
        app:title="Звонки"
        app:titleTextColor="#FFFFFF" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/floatingActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        android:layout_margin="16dp"
        android:clickable="true"
        android:focusable="true"
        app:backgroundTint="@color/colorAccent"
        app:backgroundTintMode="src_atop"
        app:srcCompat="@drawable/kek" />

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tabLayout4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="?attr/actionBarSize"
        android:background="@color/colorPrimary"
        android:isScrollContainer="true"
        app:tabIndicatorColor="@android:color/white"
        app:tabIndicatorHeight="6dp"
        app:tabMode="scrollable"
        app:tabSelectedTextColor="@android:color/white"
        app:tabTextColor="#E6E6FA">

    </com.google.android.material.tabs.TabLayout>

    <ImageButton
        android:layout_margin="16dp"
        android:id="@+id/onOff"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:background="@null"
        app:srcCompat="@drawable/on" />

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/rager"
        android:layout_width="match_parent"
        android:layout_height="557dp"
        android:layout_marginTop="105dp"
/>

</FrameLayout>

尽管此代码在主要 Activity 中有效

不知道为什么， Debug模式下没有错误

Answer 1

Kundan 的建议是正确的，但修复起来要容易得多。

你不需要这个:

final Context context = getActivity();

如果您需要访问 Fragment 中的上下文，您可以调用 requireContext() 如果您需要访问 Activity，您可以调用 requireActivity()

所以你的 toast 消息可以变成:

Toast.makeText(requireContext(),"lel",Toast.LENGTH_LONG).show();