ListView 仅显示数组列表中的第一项

Posted 2023-05-07

【中文标题】ListView 仅显示数组列表中的第一项

【英文标题】：ListView only shows the first item from the arraylist

【发布时间】：2021-02-13 12:28:59

【问题描述】：

以前，由于对资源文件的错误引用，我遇到了崩溃问题。修复了这个问题，并用我得到的逻辑错误更新了这个线程。 我是 android 新手，目前正在学习自定义类和适配器。在工作时，我遇到了一个问题，即 listview 仅显示第一个 arraylist 项。 我也附上了所需文件的代码。

工作活动

package np.com.shresthakiran.tourswoniga;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;
import java.util.ArrayList;

public class KhowpaActivity extends AppCompatActivity 
    ListView lvHeritageList;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listview_heritage);

        lvHeritageList = findViewById(R.id.lvHeritage);
        ArrayList<Heritages> heritageAryList = new ArrayList<>();
        heritageAryList.add(new Heritages(R.drawable.ic_launcher_background,"Ngatapol", "Taumadi"));
        heritageAryList.add(new Heritages(R.drawable.ic_launcher_foreground, "Dattatreya", "Taumadi"));
        heritageAryList.add(new Heritages(R.drawable.ic_launcher_foreground, "Lu dhwakha", "Lyaaku"));
        heritageAryList.add(new Heritages(R.drawable.ic_launcher_foreground, "55 jhyale Durbar", "Lyaaku"));
        heritageAryList.add(new Heritages(R.drawable.ic_launcher_foreground, "Taleju Bhawani", "Lyaaku"));


        HeritageAdapter heritageAdapter = new HeritageAdapter(KhowpaActivity.this, R.layout.heritages_row, heritageAryList);
        lvHeritageList.setAdapter(heritageAdapter);

    

自定义适配器

package np.com.shresthakiran.tourswoniga;

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

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.util.ArrayList;

public class HeritageAdapter extends ArrayAdapter<Heritages> 

    private Context mContext;
    private int mResource;
    public HeritageAdapter(@NonNull Context context, int resource, @NonNull ArrayList<Heritages> objects) 
        super(context, resource, objects);
        this.mContext = context;
        this.mResource = resource;
    

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) 
        LayoutInflater layoutInflater =LayoutInflater.from(mContext);
        convertView = layoutInflater.inflate(mResource, parent, false);
        ImageView ivHeritageImage = convertView.findViewById(R.id.ivHeritage);
        TextView tvHeritageName = convertView.findViewById(R.id.tvHeritageName);
        TextView tvHeritageAddress = convertView.findViewById(R.id.tvHeritageAddress);

        ivHeritageImage.setImageResource(getItem(position).getmImageResourceId());
        tvHeritageName.setText(getItem(position).getmHeritageName());
        tvHeritageAddress.setText(getItem(position).getmHeritageAddress());
        return  convertView;
    

对象类

package np.com.shresthakiran.tourswoniga;

public class Heritages 

    private int mImageResourceId;
    private String mHeritageName;
    private String mHeritageAddress;

    public Heritages(int heritageImageResourceId, String heritageName, String heritageAddress) 
        this.mImageResourceId = heritageImageResourceId;
        this.mHeritageName = heritageName;
        this.mHeritageAddress = heritageAddress;
    

    public int getmImageResourceId() 
        return mImageResourceId;
    

    public String getmHeritageName() 
        return mHeritageName;
    

    public String getmHeritageAddress() 
        return mHeritageAddress;
    

ListView XML

<?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:id="@+id/toolbar"
android:layout_
android:layout_
android:minHeight="100dp">

<ListView
    android:layout_
    android:layout_
    android:id="@+id/lvHeritage">
</ListView>

</RelativeLayout>

列表行 XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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_
    android:layout_
    android:orientation="horizontal"
    android:weightSum="100"
    android:layout_margin="10dp">

    <ImageView
        android:id="@+id/ivHeritage"
        android:layout_
        android:layout_
        android:layout_weight="33.33"
        android:padding="2dp"
        android:text="Ngatapol"
        android:layout_marginTop="7dp"
        android:src="@mipmap/ic_launcher"/>



    <LinearLayout
        android:id="@+id/llHeritageInfo"
        android:layout_
        android:layout_
        android:orientation="vertical"
        android:layout_weight="66.66"
        android:padding="8dp" >

        <TextView
            android:id="@+id/tvHeritageName"
            android:layout_
            android:layout_
            android:layout_weight="1"
            android:textSize="18sp"
            android:textStyle="bold"
            android:text="Ngatapol"
            android:textAppearance="?android:textAppearanceMedium"
            android:padding="2dp"/>

        <TextView
            android:id="@+id/tvHeritageAddress"
            android:layout_
            android:layout_
            android:layout_weight="1"
            android:textSize="18sp"
            android:text="Taumadi"
            android:padding="2dp"/>

    </LinearLayout>
</LinearLayout>

【问题讨论】：

在 ListView 布局文件中，我犯了一个错误。我写了 android:layout_ 实际上应该是 android:layout_ 。在 ListView XML 中将 android:layout_ 更改为 android:layout_ 解决了这个问题。

【参考方案1】：

listview 仅显示第一项是因为您已将heritages_row 布局中的高度设置为match_parent，这将覆盖整个屏幕高度，而对于下一项，您必须向下滚动，即使内容第一项没有覆盖整个高度。

要使每一行只覆盖其显示的内容，请使用wrap_content 而不是match_parent。