以下项目是从在线课程中逐字复制的。它应该显示一个列表视图，但是什么也没有显示。我是全新的安卓工作室，这只是我的第二个项目。共有5个文件，我将在下面显示每个文件的内容。我只需要另外一两双眼睛就能找到问题，因为我是“虫子盲”。任何帮助都将不胜感激。
活动\u main.xml<androidx.constraintlayout.widget.constraintlayoutxmlns: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=“匹配父项”android:layout_height=“匹配父项”tools:context=“.mainactivity”>

<ListView
    android:id="@+id/listView"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:layout_marginStart="16dp"
    android:layout_marginTop="16dp"
    android:layout_marginEnd="16dp"
    android:layout_marginBottom="16dp"
    android:visibility="visible"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.example.tadhg.uiuxadapterpractical;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.widget.ListView;

public class MainActivity extends AppCompatActivity {

  ListView lv;
  Context context;

  TypedArray images;
  String [] titleList;
  String [] descList;

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

      context = this;

      titleList = getResources().getStringArray(R.array.Languages);
      descList = 
 getResources().getStringArray(R.array.LanguageDesc);
      images = 
 getResources().obtainTypedArray(R.array.LanguageImg);

      lv = (ListView) findViewById(R.id.listView);

    }
}

我们的适配器.java
包com.example.tadhg.uiuxadapterpractical；
导入android.content.context；导入android.content.res.typedarray；导入android.view.layoutinflater；导入android.view.view；导入android.view.viewgroup；导入android.widget.baseadapter；导入android.widget.imageview；导入android.widget.textview；
公共类ouradapter扩展baseadapter{

private String [] titles;
private String [] desc;
private TypedArray imageID;

private Context context;
private static LayoutInflater layoutInflater;

//constructor
OurAdapter(Context adapterContext, String[] titleList, String[] descList, TypedArray images){
    titles = titleList;
    desc = descList;
    imageID = images;
    context = adapterContext;

    layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

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

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

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

private class ViewHolder {
    TextView tv1, tv2;
    ImageView img;
}

@Override
public View getView(int position, View view, ViewGroup viewGroup) {
    ViewHolder viewHolder = new ViewHolder();

    if (view == null) {
        view = layoutInflater.inflate(R.layout.list_layout, viewGroup, false);
        viewHolder.tv1 = (TextView)view.findViewById(R.id.textView7);
        viewHolder.tv2 = (TextView)view.findViewById(R.id.textView8);
        viewHolder.img = (ImageView) view.findViewById(R.id.imageView2);

        view.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) view.getTag();
    }

    viewHolder.tv1.setText(titles[position]);
    viewHolder.tv2.setText(desc[position]);
    viewHolder.img.setImageResource(imageID.getResourceId(position, 0));

    return view;
} }

列表\u layout.xml
<androidx.constraintlayout.widget.constraintlayoutxmlns: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=“匹配父项”android:layout_height=“匹配父项”>

<ImageView
    android:id="@+id/imageView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginStart="16dp"
    android:layout_marginTop="8dp"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:srcCompat="@drawable/cplus" />

<TextView
    android:id="@+id/textView7"
    android:layout_width="0dp"
    android:layout_height="32dp"
    android:layout_marginStart="16dp"
    android:layout_marginTop="8dp"
    android:layout_marginEnd="8dp"
    android:text="TextView"
    android:textSize="24sp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toEndOf="@+id/imageView2"
    app:layout_constraintTop_toTopOf="parent" />

<TextView
    android:id="@+id/textView8"
    android:layout_width="0dp"
    android:layout_height="24dp"
    android:layout_marginStart="16dp"
    android:layout_marginTop="8dp"
    android:layout_marginEnd="8dp"
    android:text="TextView"
    android:textSize="18sp"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toEndOf="@+id/imageView2"
    app:layout_constraintTop_toBottomOf="@+id/textView7"
    tools:text="TextView" />

</androidx.constraintlayout.widget.constraintlayout>
字符串.xml
Uiux适配器实用

<string-array name="Languages">
    <item>Java</item>
    <item>Swift</item>
    <item>C#</item>
    <item>SQL</item>
    <item>Javascript</item>
    <item>Jquery</item>
    <item>C++</item>
</string-array>

<string-array name="LanguageDesc">
    <item>Desc. of Java</item>
    <item>Desc. of Swift</item>
    <item>Desc. of C#</item>
    <item>Desc. of SQL</item>
    <item>Desc. of Javascript</item>
    <item>Desc. of Jquery</item>
    <item>Desc. of C++</item>
</string-array>

<array name="LanguageImg">
    <item>@drawable/java</item>
    <item>@drawable/swift</item>
    <item>@drawable/csharp</item>
    <item>@drawable/sql</item>
    <item>@drawable/js</item>
    <item>@drawable/jquery</item>
    <item>@drawable/cplus</item>
</array> </resources>