java .lang.NullPointerException: попытка вызвать виртуальный метод 'int android .view.View.getImportantForAccessibility ()' для ссылки на пустой объект)

Question

К сожалению app остановился в Emulator и показывает это в журнале cat (java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference)

Адаптер изображения. java

 package com.example.websoft.firstapp;

    import android.content.Context;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseAdapter;
    import android.widget.GridView;
    import android.widget.ImageView;

    /**
     * Created by websoft on 15/04/2020.
     */
    public class ImageAdapter extends BaseAdapter {
        private Context mContext;
        public int[] imageArray={
          R.drawable.bani,R.drawable.kivsachiarahoiae,R.drawable.moolmantar,R.drawable.rehmat1
            };

        public ImageAdapter(Context mContext) {
            this.mContext = mContext;
        }

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

        @Override
        public Object getItem(int position) {
            return imageArray[position];
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
           public View getView(int position, View convertView, ViewGroup parent) {

                    ImageView imageView = new ImageView(mContext);
                    imageView.setImageResource(imageArray[position]);
                    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                    imageView.setLayoutParams(new GridView.LayoutParams(340, 350));

            return null;
        }

        }

MainActivity. java

  package com.example.websoft.firstapp;

    import android.content.Intent;
    import android.os.Bundle;
    import android.support.design.widget.FloatingActionButton;
    import android.support.design.widget.Snackbar;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;
    import android.view.View;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.widget.Button;

    public class MainActivity extends AppCompatActivity {
    private Button button;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
            setSupportActionBar(toolbar);

            FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
            fab.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                            .setAction("Action", null).show();

                }
            });

            button = (Button) findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    openActivity2();
                }
            });
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.menu_main, menu);
            return true;
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            int id = item.getItemId();

            //noinspection SimplifiableIfStatement
            if (id == R.id.action_settings) {
                return true;
            }

            return super.onOptionsItemSelected(item);
        }

    public void openActivity2() {
        Intent intent = new Intent(this, Main22Activity.class);
        startActivity(intent);
    }}

Main22Activity.java
package com.example.websoft.firstapp;

import android.renderscript.RenderScript;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.GridView;

public class Main22Activity extends AppCompatActivity {
GridView gridView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main22);

        gridView=(GridView) findViewById(R.id.simpleGridView);
        gridView.setAdapter(new ImageAdapter(this));

    }
}

logcat

04-16 08:18:05.323 4955-4955/? I/art: Not late-enabling -Xcheck:jni (already on)
04-16 08:18:05.323 4955-4955/? I/art: Late-enabling JIT
04-16 08:18:05.325 4955-4955/? I/art: JIT created with code_cache_capacity=2MB compile_threshold=1000
04-16 08:18:05.634 4955-4955/com.example.websoft.firstapp W/System: ClassLoader referenced unknown path: /data/app/com.example.websoft.firstapp-1/lib/x86
04-16 08:18:06.163 4955-4962/com.example.websoft.firstapp W/art: Suspending all threads took: 5.533ms
04-16 08:18:06.637 4955-4955/com.example.websoft.firstapp D/gralloc_goldfish: Emulator without GPU emulation detected.
04-16 08:18:07.466 4955-4955/com.example.websoft.firstapp I/Choreographer: Skipped 85 frames!  The application may be doing too much work on its main thread.
04-16 08:18:08.654 4955-4966/com.example.websoft.firstapp I/art: WaitForGcToComplete blocked for 12.433ms for cause Background
04-16 08:18:08.701 4955-4955/com.example.websoft.firstapp D/AndroidRuntime: Shutting down VM
04-16 08:18:08.701 4955-4955/com.example.websoft.firstapp E/AndroidRuntime: FATAL EXCEPTION: main
                                                                            Process: com.example.websoft.firstapp, PID: 4955
                                                                            java.lang.NullPointerException: Attempt to invoke virtual method 'int android.view.View.getImportantForAccessibility()' on a null object reference
                                                                                at android.widget.AbsListView.obtainView(AbsListView.java:2363)
                                                                                at android.widget.GridView.onMeasure(GridView.java:1065)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                                at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
                                                                                at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1112)
                                                                                at android.widget.LinearLayout.onMeasure(LinearLayout.java:632)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                                at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                                                                                at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                                at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:391)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                                at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                                at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
                                                                                at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
                                                                                at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
                                                                                at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
                                                                                at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2643)
                                                                                at android.view.View.measure(View.java:18788)
                                                                                at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2100)
                                                                                at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1216)
                                                                                at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1452)
                                                                                at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
                                                                                at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
                                                                                at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
                                                                                at android.view.Choreographer.doCallbacks(Choreographer.java:670)
                                                                                at android.view.Choreographer.doFrame(Choreographer.java:606)
                                                                                at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
                                                                                at android.os.Handler.handleCallback(Handler.java:739)
                                                                                at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                at android.os.Looper.loop(Looper.java:148)
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                                at java.lang.reflect.Method.invoke(Native Method)
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
04-16 08:18:17.495 4955-4962/com.example.websoft.firstapp W/art: Suspending all threads took: 5.023ms
04-16 08:18:57.795 4955-4962/com.example.websoft.firstapp W/art: Suspending all threads took: 22.833ms
04-16 08:20:01.216 4955-4962/com.example.websoft.firstapp W/art: Suspending all threads took: 5.076ms

04-16 08: 18: 08.701 4955-4955 / com.example.websoft.firstapp E / AndroidRuntime: ИСКЛЮЧИТЕЛЬНОЕ ИСКЛЮЧЕНИЕ: основной процесс: com .example.websoft.firstapp, PID: 4955 java .lang.NullPointerException: попытка вызвать виртуальный метод 'int android .view.View.getImportantForAccessibility ()' для ссылки на пустой объект

activity_main22. 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.websoft.firstapp.Main22Activity">
<GridView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:numColumns="3"
    android:columnWidth="90dp"
    android:id="@+id/simpleGridView"

    android:layout_gravity="center" />
</LinearLayout>

activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.example.websoft.firstapp.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        android:src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>

Answer 1

Эта часть не выглядит правильно

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    ImageView imageView = new ImageView(mContext);
    imageView.setImageResource(imageArray[position]);
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setLayoutParams(new GridView.LayoutParams(340, 350));

    return null;
}

Сначала нужно накачать изображение, как-то так.

@Override
public View getView(int position, @Nullable View convertView, ViewGroup parent){
    if (convertView == null) {
        convertView = inflater.inflate(R.layout.some_list_item, parent, false);
    }

    ImageView imageView = convertView.findViewById(R.id.imageView);
    imageView.setImageResource(imageArray[position]);
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setLayoutParams(new GridView.LayoutParams(340, 350));

    return convertView;
}