如何使用BaseAdapter自定义ListView

46

我想创建一个像这样的自定义 ListView:

TextView+ImageView in ListView

我认为我需要使用 BaseAdapter 但我对此毫无头绪。


请查看以下链接中的教程:http://www.androidhive.info/2012/02/android-custom-listview-with-image-and-text/ - Raghunandan
5个回答

59

主文件.xml:

<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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

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

    </ListView>

</RelativeLayout>

自定义.xml文件:

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <LinearLayout
            android:layout_width="255dp"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

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

                <TextView
                    android:id="@+id/title"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Video1"
                    android:textAppearance="?android:attr/textAppearanceLarge"
                    android:textColor="#339966"
                    android:textStyle="bold" />
            </LinearLayout>

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

                <TextView
                    android:id="@+id/detail"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="video1"
                    android:textColor="#606060" />
            </LinearLayout>
        </LinearLayout>

        <ImageView
            android:id="@+id/img"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_launcher" />

    </LinearLayout>

</LinearLayout>

主文件.java:

package com.example.sample;

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;


public class MainActivity extends Activity {

    ListView l1;
    String[] t1={"video1","video2"};
    String[] d1={"lesson1","lesson2"};
    int[] i1 ={R.drawable.ic_launcher,R.drawable.ic_launcher};


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        l1=(ListView)findViewById(R.id.list);
        l1.setAdapter(new dataListAdapter(t1,d1,i1));
    }

    class dataListAdapter extends BaseAdapter {
        String[] Title, Detail;
        int[] imge;

        dataListAdapter() {
            Title = null;
            Detail = null;
            imge=null;
        }

        public dataListAdapter(String[] text, String[] text1,int[] text3) {
            Title = text;
            Detail = text1;
            imge = text3;

        }

        public int getCount() {
            // TODO Auto-generated method stub
            return Title.length;
        }

        public Object getItem(int arg0) {
            // TODO Auto-generated method stub
            return null;
        }

        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {

            LayoutInflater inflater = getLayoutInflater();
            View row;
            row = inflater.inflate(R.layout.custom, parent, false);
            TextView title, detail;
            ImageView i1;
            title = (TextView) row.findViewById(R.id.title);
            detail = (TextView) row.findViewById(R.id.detail);
            i1=(ImageView)row.findViewById(R.id.img);
            title.setText(Title[position]);
            detail.setText(Detail[position]);
            i1.setImageResource(imge[position]);

            return (row);
        }
    }
}

试试这个。


使用了这个代码,但是出现了下面的异常 java.lang.ArrayIndexOutOfBoundsException: length=10; index=10 - MohanRaj S
4
为了提高性能,你需要使用 ViewHolder。查看此链接:http://stackoverflow.com/questions/19469073/how-do-you-efficiently-load-bitmaps-from-drawable-folder-into-a-listview/19469076#19469076。 - Vrajesh
@ShaktisinhJadeja,布局填充器来自活动类,因为适配器是在其中实现的。如果它是一个独立的类,请尝试使用LayoutInflater.from(context)。 - Lin

15
public class ListElementAdapter extends BaseAdapter{

    String[] data;
    Context context;
    LayoutInflater layoutInflater;


    public ListElementAdapter(String[] data, Context context) {
        super();
        this.data = data;
        this.context = context;
        layoutInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {

        return data.length;
    }

    @Override
    public Object getItem(int position) {

        return null;
    }

    @Override
    public long getItemId(int position) {

        return position;
    }

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


        convertView= layoutInflater.inflate(R.layout.item, null);

        TextView txt=(TextView)convertView.findViewById(R.id.text);

        txt.setText(data[position]);



        return convertView;
    }
}

只需在您的主活动中调用ListElementAdapter并将适配器设置为ListView即可。


我该如何使用它?ListElementAdapter adapter = new ListElementAdapter(array, this); 将无法工作,因为它扩展了BaseAdapter,而BaseAdapter是一个抽象类。 - eawedat
1
由于答案过时,而且在Android中ListView已经被弃用。我建议您使用RecyclerView代替。谢谢。 - Ganesh Katikar

7
创建自己的BaseAdapter类,并按照以下方式使用。
 public class NotificationScreen extends Activity
{

@Override
protected void onCreate_Impl(Bundle savedInstanceState)
{
    setContentView(R.layout.notification_screen);

    ListView notificationList = (ListView) findViewById(R.id.notification_list);
    NotiFicationListAdapter notiFicationListAdapter = new NotiFicationListAdapter();
    notificationList.setAdapter(notiFicationListAdapter);

    homeButton = (Button) findViewById(R.id.home_button);

}

}

制作您自己的BaseAdapter类及其单独的xml文件。
public class NotiFicationListAdapter  extends BaseAdapter
{
private ArrayList<HashMap<String, String>> data;
private LayoutInflater inflater=null;


public NotiFicationListAdapter(ArrayList data)
{
this.data=data;        
    inflater =(LayoutInflater)baseActivity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}



public int getCount() 
{
 return data.size();
}



public Object getItem(int position) 
{
 return position;
}



public long getItemId(int position) 
{
    return position;
}



public View getView(int position, View convertView, ViewGroup parent) 
{
View vi=convertView;
    if(convertView==null)

    vi = inflater.inflate(R.layout.notification_list_item, null);

    ImageView compleatImageView=(ImageView)vi.findViewById(R.id.complet_image);
    TextView name = (TextView)vi.findViewById(R.id.game_name); // name
    TextView email_id = (TextView)vi.findViewById(R.id.e_mail_id); // email ID
    TextView notification_message = (TextView)vi.findViewById(R.id.notification_message); // notification message



    compleatImageView.setBackgroundResource(R.id.address_book);
    name.setText(data.getIndex(position));
    email_id.setText(data.getIndex(position));
    notification_message.setTextdata.getIndex(position));

    return vi;
}

  }

BaseAdapter XML文件。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/inner_layout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginLeft="10dp"
android:layout_weight="4"
android:background="@drawable/list_view_frame"
android:gravity="center_vertical"
android:padding="5dp" >

<TextView
    android:id="@+id/game_name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Game name"
    android:textColor="#FFFFFF"
    android:textSize="15dip"
    android:textStyle="bold"
    android:typeface="sans" />

<TextView
    android:id="@+id/e_mail_id"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/game_name"
    android:layout_marginTop="1dip"
    android:text="E-Mail Id"
    android:textColor="#FFFFFF"
    android:textSize="10dip" />

<TextView
    android:id="@+id/notification_message"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/game_name"
    android:layout_toRightOf="@id/e_mail_id"
    android:paddingLeft="5dp"
    android:text="Notification message"
    android:textColor="#FFFFFF"
    android:textSize="10dip" />



<ImageView
    android:id="@+id/complet_image"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:layout_marginBottom="30dp"
    android:layout_marginRight="10dp"
    android:src="@drawable/complete_tag"
    android:visibility="invisible" />

</RelativeLayout>

根据需要做相应更改并使用。


4
private class ObjectAdapter extends BaseAdapter {

    private Context context;
    private List<Object>objects;

    public ObjectAdapter(Context context, List<Object> objects) {
        this.context = context;
        this.objects = objects;
    }

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

    @Override
    public Object getItem(int position) {
        return objects.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if(convertView==null){
            holder = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(android.R.layout.simple_list_item_1, parent, false);
            holder.text = (TextView) convertView.findViewById(android.R.id.text1);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }

        holder.text.setText(getItem(position).toString()));
        return convertView;
    }

    class ViewHolder {
        TextView text;
    }
}

我该如何使用它? ObjectAdapter适配器=新的ObjectAdapter(this, objects); 无法工作,因为它扩展了BaseAdapter,而BaseAdapter是一个抽象类。 - eawedat

4

我建议使用自定义适配器,首先创建一个Xml文件,例如layout/customlistview.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" >
    <ImageView
        android:id="@+id/image"
        android:layout_alignParentRight="true"
        android:paddingRight="4dp" />
    <TextView
        android:id="@+id/title"
        android:layout_toLeftOf="@id/image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="23sp"
        android:maxLines="1" />
    <TextView
        android:id="@+id/subtitle"
        android:layout_toLeftOf="@id/image" android:layout_below="@id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" /> 
</RelativeLayout>

假设您有一个类似于这样的自定义类:
public class CustomClass {

    private long id;
    private String title, subtitle, picture;

    public CustomClass () {
    }

    public CustomClass (long id, String title, String subtitle, String picture) {
        this.id = id;
        this.title= title;
        this.subtitle= subtitle;
        this.picture= picture;
    }
    //add getters and setters
}

一个CustomAdapter.java使用xml布局。

public class CustomAdapter extends ArrayAdapter {

private Context context;
private int resource;
private LayoutInflater inflater;

public CustomAdapter (Context context, List<CustomClass> values) { // or String[][] or whatever

    super(context, R.layout.customlistviewitem, values);

    this.context = context;
    this.resource = R.layout.customlistview;
    this.inflater = LayoutInflater.from(context);
}

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

    convertView = (RelativeLayout) inflater.inflate(resource, null);

    CustomClass item = (CustomClass) getItem(position);

    TextView textviewTitle = (TextView) convertView.findViewById(R.id.title);
    TextView textviewSubtitle = (TextView) convertView.findViewById(R.id.subtitle);
    ImageView imageview = (ImageView) convertView.findViewById(R.id.image);

    //fill the textviews and imageview with the values
    textviewTitle = item.getTtile();
    textviewSubtitle = item.getSubtitle();

    if (item.getAfbeelding() != null) {
        int imageResource = context.getResources().getIdentifier("drawable/" + item.getImage(), null, context.getPackageName());
        Drawable image = context.getResources().getDrawable(imageResource);
    }
    imageview.setImageDrawable(image);

    return convertView;
    }
}

你成功地完成了吗? 如果你想要更多信息,随时提问 :) 编辑:将适配器更改为适用于列表而不仅仅是列表。

请问,我该如何在我的活动中使用这个类,其中包含一个名为“lv”的列表视图?另外,在这一行代码中,“toerismelistviewitem”的目的是什么:“super(context, R.layout.toerismelistviewitem, values);”? - Mohsen Bahman
嗨,只需填写您的Xml文件名称,因此在您的情况下,它将是super(context,R.layout.lv,values) - 我忘记重命名它了 :) 我刚刚得到了一个List<String> values,但可能希望将您的字符串放在具有2个维度的列表中,因为您有标题和副标题,您可以根据自己的需要更改它,记住这一点。 - T_D
我使用了List<CustomClass>而不是List<String>,这样它将同时提供字符串和图像的URL。请查看我的编辑,希望现在更清楚了... - T_D

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