列表视图一遍又一遍地只显示最后一项

Listview show only last item over and over

我是 android 开发的新手。我注册了 Udacity 课程,我到达了必须使用服装 arrayAdapter 来显示数据列表视图(文本)的地方,我确定了其中的大部分内容,但我在显示数据时遇到了问题,即:当我启动我的 activity listView 显示 arraylist 上的最后一项 我已经尝试了几乎所有方法,但对我没有用

我的数据

/**
 * Displays text to the user.
 */
public class Numbers {


    //First we Set the Stat of our Class :

    // English Translation
    public static String englishTranslation;

    //Tamazight Translation
    public static String tamazightTranslation;

    /**
     * Create a new Numbers Object :
     *
     * @param englishTranslation   is for ENGLISH NUMBERS
     * @param tamazightTranslation is for TAMAZIGHT NUMBERS
     */

    //Constructor
    public Numbers(String englishTranslation, String tamazightTranslation) {


        this.englishTranslation = englishTranslation;
        this.tamazightTranslation = tamazightTranslation;

    }

    //Getter
    public static String getEnglishTranslation() {
        return englishTranslation;
    }


    public static String getTamazightTranslation() {
        return tamazightTranslation;
    }


}


我的数组列表:

public class ActivityNumbers extends AppCompatActivity {

    //Add English numbers to The ARRAYList
    ArrayList<Numbers> englishNumbers = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_numbers);



        englishNumbers.add(new Numbers("One", "Yan"));
        englishNumbers.add(new Numbers("Two", "Sin"));
        englishNumbers.add(new Numbers("Three", "Krad"));
        englishNumbers.add(new Numbers("Four", "Koz"));
        englishNumbers.add(new Numbers("Five", "Smos"));
        englishNumbers.add(new Numbers("Six", "Sdis"));
        englishNumbers.add(new Numbers("Seven", "Sa"));
        englishNumbers.add(new Numbers("Eight", "Tam"));
        englishNumbers.add(new Numbers("Nine", "Tza"));
        englishNumbers.add(new Numbers("Ten", "Mraw"));

        //EnglishNumbers.remove(0);
        //EnglishNumbers.size();
        // EnglishNumbers.get(1);
        //Create a NEW TV object




        /**Creating an ArrayAdapter (DATA HOLDER)
         @param Context / the ACTIVITY concerned
         @param Android.R.layout : an XML layout file contains TextView predefined by Android
         @param Items to display */


        NumbersAdapter itemsAdapter = new NumbersAdapter (this, englishNumbers);

        // Linking the ListView object to a Variable
        ListView numbersListView = (ListView) findViewById(R.id.list);
        //Calling setAdapter Method on numbersListView with "itemsAdapter
        numbersListView.setAdapter(itemsAdapter);


    }


}


我的适配器:

public class NumbersAdapter extends ArrayAdapter<Numbers> {

    public NumbersAdapter(Context context, ArrayList<Numbers> englishNumbers) {
        super(context, 0, englishNumbers);
    }

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

        View listItemView = convertView;
        if (listItemView == null) {
            listItemView = LayoutInflater.from(getContext()).inflate(R.layout.listitem, parent, false);
        }

        Numbers numbers = getItem(position);


        System.out.println(position);

        TextView tamazight_item = (TextView) listItemView.findViewById(R.id.tamazight_item);
        TextView english_item = (TextView) listItemView.findViewById(R.id.english_item);


        tamazight_item.setText(numbers.getEnglishTranslation());
        System.out.println(numbers.getEnglishTranslation());

        english_item.setText(numbers.getTamazightTranslation());

        System.out.println(numbers.getTamazightTranslation());


        return listItemView;

    }
}

您的 tamazightTranslationenglishTranslation 属性在 Numbers class 上是静态的,这意味着它们是 class 属性。从变量和吸气剂中删除 static ,你应该没问题。在此处查看 class 属性和实例属性之间的区别 https://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html

试试这个方法

Context context; 
ArrayList<Numbers> englishNumbers;

public NumbersAdapter(Context context, ArrayList<Numbers> englishNumbers) 
{
  this.context=context;
  this.englishNumbers=englishNumbers;
}

@Override
public View getView(int position, View convertView, ViewGroup parent)
{
    convertView= LayoutInflater.from(context).inflate(R.layout.listitem,parent,false);

    TextView tamazight_item = (TextView) listItemView.findViewById(R.id.tamazight_item);
    TextView english_item = (TextView) listItemView.findViewById(R.id.english_item);


    tamazight_item.setText(englishNumbers.get(position).getEnglishTranslation());
    english_item.setText(englishNumbers.get(position).getTamazightTranslation());

    return convertView;
}

并且不要忘记让 NumbersAdapter 扩展 BaseAdapter

我已经更改了您的型号 class 和适配器 class 请按照此操作 它会起作用

 public class Numbers {
    //First we Set the Stat of our Class :

    // English Translation
    private String englishTranslation;

    //Tamazight Translation
    private  String tamazightTranslation;

    public String getEnglishTranslation() {
        return englishTranslation;
    }

    public void setEnglishTranslation(String englishTranslation) {
        this.englishTranslation = englishTranslation;
    }

    public String getTamazightTranslation() {
        return tamazightTranslation;
    }

    public void setTamazightTranslation(String tamazightTranslation) {
        this.tamazightTranslation = tamazightTranslation;
    }
}


适配器 Class

    public class NumbersAdapter extends ArrayAdapter<Numbers> {
     private Context mContext;
     private ArrayList<Numbers>list;
     public NumbersAdapter(Context context, ArrayList<Numbers> englishNumbers) {
      super(context, 0, englishNumbers);
      this.mContext=context;
      this.list = englishNumbers;
    }

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

        View listItemView = convertView;
        if (listItemView == null) {
            listItemView = LayoutInflater.from(mContext).inflate(R.layout.listitem, parent, false);
        }

        Numbers numbers = list.get(position);


        System.out.println(position);

        TextView tamazight_item = (TextView) listItemView.findViewById(R.id.tamazight_item);
        TextView english_item = (TextView) listItemView.findViewById(R.id.english_item);


        tamazight_item.setText(numbers.getEnglishTranslation());
        System.out.println(numbers.getEnglishTranslation());

        english_item.setText(numbers.getTamazightTranslation());

        System.out.println(numbers.getTamazightTranslation());


        return listItemView;

    }
}

如果它在您的列表视图中显示最后一项,可能有多种原因。

  1. 您需要覆盖 ArrayAdapter 中的 getCount() 以获得列表的大小。它可能会解决问题。

  2. 确保列表视图未在 xml 布局中的滚动视图内声明。如果是,请使用 nestedscrollview 或其他方式正确处理它。

如果它在列表视图的所有行中显示相同的数据,那么它可能是

  1. 在你的情况下,你需要去掉属性前面的static关键字,static表示属性或方法属于Number class,而不是你Number的实例class 对象。基本上肯定是这个原因。