Question

MainActivity.java

public class MainActivity extends Activity {

ListView list;
String[] titles;
String[] description;
int imgs[]={R.drawable.facebook,R.drawable.instagram,R.drawable.twitter,R.drawable.google};

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

    Resources res = getResources();

    titles = res.getStringArray(R.array.titles);
    description = res.getStringArray(R.array.description);

    list = (ListView) findViewById(R.id.list1);

    MyAdapter adapter = new MyAdapter(this,titles,imgs,description);
    list.setAdapter(adapter);

    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Toast.makeText(getApplicationContext(),Integer.toString(position),Toast.LENGTH_LONG).show();
        }
    });
}


class MyAdapter extends ArrayAdapter<String> {

    Context context;
    String myTitles[];
    String myDescription[];
    int[] imgss;

    MyAdapter(Context c, String[] titles, int[] img, String[] description) {
        super(c,R.layout.row,R.id.text1,titles);
        this.context=c;
        this.imgss=img;
        this.myTitles=titles;
        this.myDescription=description;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater layoutInflater = (LayoutInflater)   getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View row = layoutInflater.inflate(R.layout.row, parent, false);
    ImageView images = (ImageView) findViewById(R.id.logo);
    TextView myTitle = (TextView) findViewById(R.id.text1);
    TextView myDescription = (TextView) findViewById(R.id.text2);
    images.setImageResource(R.drawable.facebook);
    images.setImageResource(imgs[position]);
    myTitle.setText(titles[position]);
    myDescription.setText(description[position]);
    return row;   
    }
  }
}

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout     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:padding="16dp"
tools:context="com.apakdroid.customlistview.MainActivity" >

    <ListView
        android:id="@+id/list1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true" />

</RelativeLayout>

row.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:padding="5dp"
    android:id="@+id/logo"
    android:src="@mipmap/ic_launcher"/>

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="2dp"
        android:textColor="#33CC33"
        android:id="@+id/text1"
        android:layout_marginTop="5dp"
        android:layout_marginLeft="10dp"
        android:text="Medium Text"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/text2"
        android:layout_marginLeft="10dp"
        android:text="TextView" />

</LinearLayout>

的strings.xml

<resources>
<string name="app_name">Custom ListView</string>
<string-array name="titles">
    <item>Facebook</item>
    <item>Instagram</item>
    <item>Twitter</item>
    <item>Google</item>
</string-array>

<string-array name="description">
    <item>Facebook Description</item>
    <item>Instagram Description</item>
    <item>Twitter Description</item>
    <item>Google Description</item>
</string-array>

截图（Android和Logcat）： - http://imgur.com/a/816Q1

ArrayAdapter仅显示strings.xml中的最后一个值和img数组中的最后一个图像。无法显示所有图像和文字。

行 images.setImageResource（imgs [position]）中有一个错误为NullPointerException。屏幕截图中附有 Logcat 。

Answer 1

我认为您的问题可能出在getView方法或适配器中。你应该使用＆＃39; row＆＃39;查找子控件。

View row = layoutInflater.inflate(R.layout.row, parent, false);
ImageView images = (ImageView) row.findViewById(R.id.logo);
TextView myTitle = (TextView) row.findViewById(R.id.text1);
TextView myDescription = (TextView) row.findViewById(R.id.text2);

Answer 2

您需要将 LayoutManager 添加到listView / RecyclerView。在设置适配器之前。

怎么做：

rvCategories.setHasFixedSize(true);
rvCategories.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));

请记住，我们有更多布局经理......

您需要初始化组件。细节：row.findViewById。

View row = layoutInflater.inflate(R.layout.row, parent, false);
ImageView images = (ImageView) row.findViewById(R.id.logo);
TextView myTitle = (TextView) row.findViewById(R.id.text1);
TextView myDescription = (TextView) row.findViewById(R.id.text2);

Answer 3

我认为问题出在你的getView（）方法中。您忘记将视图对象放入查找ID。

View row = layoutInflater.inflate(R.layout.row, parent, false);
ImageView images = (ImageView) row.findViewById(R.id.logo);
TextView myTitle = (TextView) row.findViewById(R.id.text1);
TextView myDescription = (TextView) row.findViewById(R.id.text2);

我正在尝试使用ArrayAdapter实现自定义列表视图，但所有项目都没有显示在屏幕上

3 个答案: