java - 帐户设置适配器问题

我创建了一个帐户设置页面，其中包含通过片段打开的多个选项。但是，我似乎面临着一个我无法解决的问题。我尝试了多种解决方案，但似乎会出错。感谢您的帮助！

单击该按钮以打开AccountSettingsActivity时，应用程序崩溃。错误如下。

这是我的代码：

AccountSettingsActivity.java

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageButton;
import android.widget.ListView;
import android.widget.RelativeLayout;

import com.archive.pod.R;
import com.archive.pod.Utils.SectionsStatePagerAdapter;

import java.util.ArrayList;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;

public class AccountSettingsActivity extends AppCompatActivity {

  //Initializing
  private Context mContext;
  private SectionsStatePagerAdapter pagerAdapter;
  private ViewPager mViewPager;
  private RelativeLayout mRelativeLayout;

  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_accountsettings);

    mContext = AccountSettingsActivity.this;
    mViewPager = findViewById(R.id.container);
    mRelativeLayout = findViewById(R.id.relLayout1);

    //Account Settings Options List Initializer
    setupSettingsList();

    //Account Settings Options Fragment Initializer
    setupFragments();

    //Back Arrow Initialization for Navigation Back to "Profile Activity"
    ImageButton backArrow = findViewById(R.id.back_arrow);
    backArrow.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        finish();
      }
    });
  }

  private void setupFragments() {
    pagerAdapter = new SectionsStatePagerAdapter(getSupportFragmentManager());
    pagerAdapter.addFragment(new EditProfileFragment(), getString(R.string.editProfile)); //fragment 0
    pagerAdapter.addFragment(new LogoutFragment(), getString(R.string.logout)); // fragment 1
  }

  //Allows for the overlay to show fragment on top of account settings activity
  private void setViewPager(int fragmentNumber) {
    mRelativeLayout.setVisibility(View.GONE);
    mViewPager.setAdapter(pagerAdapter);
    mViewPager.setCurrentItem(fragmentNumber);
  }

  //All Options in Account Settings
  private void setupSettingsList() {
    ListView listView = findViewById(R.id.lvAccountSettings);

    ArrayList < Object > options = new ArrayList < > ();
    options.add(("My Account"));
    options.add(new AccountSettingsOptions("Edit Profile", "Change your profile information.")); //fragment 0
    options.add(("Notifications"));
    options.add(new AccountSettingsOptions("Notifications", "Manage preferences for notifications.")); //fragment 1
    options.add(("Privacy Settings"));
    options.add(new AccountSettingsOptions("Privacy", "Manage your privacy settings.")); //fragment 2
    options.add(new AccountSettingsOptions("Privacy Policy", "Important for both of us.")); //fragment 3
    options.add(("More"));
    options.add(new AccountSettingsOptions("Ads", "Learn more about the ads you see.")); //fragment 4
    options.add(new AccountSettingsOptions("Support", "Get help from us and the community.")); //fragment 5
    options.add(new AccountSettingsOptions("Logout", "See you next time.")); //fragment 6

    listView.setAdapter(new AccountSettingsAdapter(this, options));

    //Navigation to fragment page
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
      @Override
      public void onItemClick(AdapterView < ? > parent, View view, int position, long id) {
        setViewPager(position);
      }
    });
  }
}

AccountSettingsAdapter.java

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.archive.pod.R;

import java.util.ArrayList;

public class AccountSettingsAdapter extends BaseAdapter {

  ArrayList < Object > list;
  private static final int OPTIONS = 0;
  private static final int HEADER = 1;
  private LayoutInflater inflater;

  public AccountSettingsAdapter(Context context, ArrayList < Object > list) {
    this.list = list;
    inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  }

  @Override
  public int getItemViewType(int position) {

    if (list.get(position) instanceof AccountSettingsOptions) {
      return OPTIONS;

    } else {
      return HEADER;
    }
  }

  @Override
  public int getViewTypeCount() {
    return 2;
  }

  @Override
  public int getCount() {
    return list.size();
  }

  @Override
  public Object getItem(int i) {
    return list.get(i);
  }

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

  /** This distinguishes between section title and list view options,
  then using switch it beings to populate the options in the list
  view with titles and descriptions */

  @Override
  public View getView(int i, View view, ViewGroup viewGroup) {
    if (view == null) {
      switch (getItemViewType(i)) {
        case OPTIONS:
          view = inflater.inflate(R.layout.activity_accountsettings, viewGroup, false);
          break;
        case HEADER:
          view = inflater.inflate(R.layout.listview_section_header_accountsettings, viewGroup, false);
          break;
      }
    }
    switch (getItemViewType(i)) {
      case OPTIONS:
        TextView name = view.findViewById(R.id.listViewTitle);
        TextView description = view.findViewById(R.id.listViewDescription);

        name.setText(((AccountSettingsOptions) list.get(i)).getName());
        description.setText(((AccountSettingsOptions) list.get(i)).getDescription());
        break;
      case HEADER:

        TextView title = view.findViewById(R.id.optionListViewHeader);
        title.setText(((String) list.get(i)));
        break;
    }
    return view;
  }
}

AccountSettingsOptions.java

public class AccountSettingsOptions {
  private String name;
  private String description;

  public AccountSettingsOptions(String name, String description) {
    this.name = name;
    this.description = description;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public String getDescription() {
    return description;
  }

  public void setDescription(String description) {
    this.description = description;
  }

}

activity_accountsettings.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/relLayout1">

        <!-- *************** Top Section ***************** -->

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/relLayout2">

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

        </RelativeLayout>

        <!-- *************** Middle Section ***************** -->

        <RelativeLayout
            android:id="@+id/relLayout3"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@id/relLayout2"
            android:padding="30dp"
            android:background="@color/windowBackground">

                <ListView
                    android:id="@+id/lvAccountSettings"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:divider="@null"
                    android:dividerHeight="0dp">

                </ListView>

        </RelativeLayout>

    </RelativeLayout>

</androidx.coordinatorlayout.widget.CoordinatorLayout>

错误：

E / AndroidRuntime: FATAL EXCEPTION: main
Process: com.archive.pod, PID: 22146
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)'
on a null object reference
at com.archive.pod.Profile.AccountSettingsAdapter.getView(AccountSettingsAdapter.java: 78)
at android.widget.AbsListView.obtainView(AbsListView.java: 2405)
at android.widget.ListView.makeAndAddView(ListView.java: 2071)
at android.widget.ListView.fillDown(ListView.java: 797)
at android.widget.ListView.fillFromTop(ListView.java: 859)
at android.widget.ListView.layoutChildren(ListView.java: 1842)
at android.widget.AbsListView.onLayout(AbsListView.java: 2202)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java: 1103)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java: 1103)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at androidx.coordinatorlayout.widget.CoordinatorLayout.layoutChild(CoordinatorLayout.java: 1183)
at androidx.coordinatorlayout.widget.CoordinatorLayout.onLayoutChild(CoordinatorLayout.java: 870)
at androidx.coordinatorlayout.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java: 889)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java: 332)
at android.widget.FrameLayout.onLayout(FrameLayout.java: 270)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java: 1829)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java: 1673)
at android.widget.LinearLayout.onLayout(LinearLayout.java: 1582)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java: 332)
at android.widget.FrameLayout.onLayout(FrameLayout.java: 270)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java: 1829)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java: 1673)
at android.widget.LinearLayout.onLayout(LinearLayout.java: 1582)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java: 332)
at android.widget.FrameLayout.onLayout(FrameLayout.java: 270)
at com.android.internal.policy.DecorView.onLayout(DecorView.java: 779)
at android.view.View.layout(View.java: 22466)
at android.view.ViewGroup.layout(ViewGroup.java: 6304)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java: 3157)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java: 2614)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java: 1745)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java: 7768)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java: 967)
at android.view.Choreographer.doCallbacks(Choreographer.java: 791)
at android.view.Choreographer.doFrame(Choreographer.java: 726)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java: 952)
at android.os.Handler.handleCallback(Handler.java: 883)
at android.os.Handler.dispatchMessage(Handler.java: 100)
at android.os.Looper.loop(Looper.java: 214)
at android.app.ActivityThread.main(ActivityThread.java: 7356)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java: 492)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java: 930)

我已经包含了所有代码，请随时创建您自己的项目！

最佳答案

listView.setOnItemClickListener ... onItemClick（AdapterView < parent上有语法错误。通配符前还有一个
不知道这是否是错误的原因。