ListView控件的使用
目录
一、ListView的属性
二、常用适配器（Adapter）
1、BaseAdapter
BaseAdapter例子：
2、SimpleAdapter
SimpleAdapter例子：
3、ArrayAdapter
ArrayAdapter例子：
一、ListView的属性
常用属性：
| 属性名称 | 功能描述 |
| android:listSelector | 当条目被点击后，改变条目的背景颜色 |
| android:dividerHeight | 设置分割线的高度 |
| android:divider | 设置分割线的颜色 |
| android:scrollbars | 是否显示滚动条 |
| android：cacheColorHint | 去除listview拖动时的背景色 |
| android:fadingEdge | 去掉上边和下边的黑色阴影 |
二、常用适配器（Adapter）
在给ListView添加数据的时候会使用到适配器，适配器是数据和视图之间的桥梁。下面就简单介绍一下ListView常用的适配器。
1、BaseAdapter
BaseAdapter是一个抽象类，它的主要用途是将一组数据传到ListView、Spinner、Callery及GridView等UI显示组件，该类有四个抽象方法，通常在写适配器类时，需要继承BaseAdapter，实现其四个抽象方法。
| 方法名 | 功能描述 |
| public int getCount() | 获取Item条目的总数 |
| public Object getItem(int position) | 根据position获取某个条目对象 |
| public long getItemId(int position) | 根据位置获取某个条目的id |
| public View getView(int position,View convertView, ViewGroup parent) | 获取相应的position对应的item视图，position是当前的item的位置。convertView是用于复用旧图，parent用来加载XML布局 |
BaseAdapter例子：
MainActivity:
package com.example.baseadapter_listview;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private ListView mListView;
public String titles[] = {"桌子","苹果","蛋糕","毛衣"};
public String prices[] = {"1800元","10/kg","30元","70元"};
public int icons[] = {R.drawable.table,R.drawable.apple,R.drawable.cake,R.drawable.sweater};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mListView = findViewById(R.id.list_view);
MyAdapter adapter = new MyAdapter();
mListView.setAdapter(adapter);
mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
Toast.makeText(MainActivity.this,"物品："+titles[position]+" 价格："+prices[position],Toast.LENGTH_LONG).show();
}
});
}
class MyAdapter extends BaseAdapter{
@Override
public int getCount() {
return titles.length;
}
@Override
public Object getItem(int position) {
return titles[position];
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView==null) {
convertView = View.inflate(MainActivity.this,R.layout.list_item,null);
holder = new ViewHolder();
holder.title = convertView.findViewById(R.id.title_t);
holder.price = convertView.findViewById(R.id.price);
holder.imageView = convertView.findViewById(R.id.image_i);
convertView.setTag(holder);
}else {
holder = (ViewHolder) convertView.getTag();
}
holder.title.setText(titles[position]);
holder.imageView.setImageResource(icons[position]);
holder.price.setText(prices[position]);
return convertView;
}
}
class ViewHolder{
TextView title,price;
ImageView imageView;
}
}
总体来说，BaseAdapter类的实现步骤如下:
(1)、创建bean数据集合对象，用来封装数据。
(2)、在MainActivity中，初始化数据集合对象bean。
(3)、创建ViewHolder类，创建布局映射关系。
(4)、 判断convertView，为空则创建，并设置Tag，不为空则通过Tag取出ViewHolder。
(5)、为ViewHolder的控件设置数据。
activity_main:
list_item:
效果图：
2、SimpleAdapter
SimpleAdapter是继承BaseAdapter的，实现了BaseAdapter的四个抽象方法封装，因此，使用SimpleAdapter时，在其构造器传入参数即可。
public SimpleAdapter(Context context, List>data, int resource, String [ ] from, int [ ] to)
| context | 表示上下文 |
| data | 数据集合，data中的每一项对应的ListView控件的条目的数据 |
| resource | Item布局的id |
| from | Map集合的key值 |
| to | Item布局中的对应控件 |
SimpleAdapter例子：
MainActivity:
package com.example.simpleadapter;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
int []imageid =new int[]{R.drawable.img1,R.drawable.img2,R.drawable.img3,R.drawable.img6,R.drawable.img4,R.drawable.img5} ;
String title []= new String[]{"图片一","图片二","图片三","图片四","图片五","图片六"};
List>listtem= new ArrayList<>();
for (int i = 0; i < imageid.length; i++) {
Mapmap =new HashMap<>();
map.put("image",imageid[i]);
map.put("name",title[i]);
listtem.add(map);
}
// SimpleAdapter(Context context, List> data,
// int resource, String[] from, int[] to)
// context：上下文
// data：数据源，一个包含Map的数据集合
// resource：item的布局文件
// from：数据来源的key的数组，与data的Map里的key对应
// to: from中的每一项数据源 对应到的 item布局中对应组件的 id。
SimpleAdapter adapter =new SimpleAdapter(this,listtem,R.layout.item,new String[]{"name","image"}
,new int []{R.id.title,R.id.photo});
ListView listView = findViewById(R.id.listview);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView adapterView, View view, int i, long l) {
Map map = (Map) adapterView.getItemAtPosition(i);
Toast.makeText(MainActivity.this,map.get("name").toString(),Toast.LENGTH_LONG).show();
}
});
}
} activity_main:
item:
效果图：
3、ArrayAdapter
ArrayAdapter也是继承BaseAdapter的，实现了BaseAdapter的四个抽象方法封装，因此，使用ArrayAdapterr时，在其构造器传入参数即可。
ArrayAdapter的构造器如下：
public ArrayAdapter(Context context, int resource);
public ArrayAdapter(Context context, int resource, int textViewResourceId);
public ArrayAdapter(Context context, int resource, T [ ] object);
public ArrayAdapter(Context context, int resource, int textViewResourceId, T [ ] object);
public ArrayAdapter(Context context, int resource, List
object); public ArrayAdapter(Context context, int resource, int textViewResourceId,List
object);
| context | 表示上下文 |
| texViewResourceId | Item布局相应的TextView的id |
| resource | Item布局的id |
| T [] objects | 需要适配的数组类型的数据 |
| List |
需要适配的集合类型的数据 |
ArrayAdapter例子：
案例一：
使用的构造器是public ArrayAdapter(Context context, int resource, int textViewResourceId,List
MainActivity布局：
package com.example.arrayadapter_listview;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity extends AppCompatActivity {
// 准备数据
private String[] data = { "Apple", "Banana", "Orange", "Watermelon",
"Pear", "Grape", "Pineapple", "Strawberry", "Cherry", "Mango",
"Apple", "Banana", "Orange", "Watermelon", "Pear", "Grape",
"Pineapple", "Strawberry", "Cherry", "Mango" };
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 创建适配器
ArrayAdapter adapter = new ArrayAdapter(
MainActivity.this,R.layout.item,R.id.text,data);
ListView listView = (ListView) findViewById(R.id.list_view);
// 绑定适配器
listView.setAdapter(adapter);
package com.example.arrayadapter_listview;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
// 准备数据
private String[] data = { "Apple", "Banana", "Orange", "Watermelon",
"Pear", "Grape", "Pineapple", "Strawberry", "Cherry", "Mango",
"Apple", "Banana", "Orange", "Watermelon", "Pear", "Grape",
"Pineapple", "Strawberry", "Cherry", "Mango" };
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 创建适配器
ArrayAdapter adapter = new ArrayAdapter(
MainActivity.this,R.layout.item,R.id.text,data);
ListView listView = (ListView) findViewById(R.id.list_view);
// 绑定适配器
listView.setAdapter(adapter);
// 点击事件
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
Toast.makeText(MainActivity.this,data[position],Toast.LENGTH_LONG).show();
}
});
}
}
}
}
activity_main布局：
item布局：
运行结果：
案例二：
MainActivity:
package com.example.arrayadapter2_listview;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
// 准备数据
List mFruits = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 初始化数据
initData();
// 创建适配器
MyAdapter myAdapter = new MyAdapter(MainActivity.this,R.layout.fruit_item,mFruits);
ListView listView = findViewById(R.id.list_view);
// 设置适配器
listView.setAdapter(myAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
Fruit fruit = mFruits.get(position);
Toast.makeText(MainActivity.this,"您点击了"+fruit.getName(),Toast.LENGTH_LONG).show();
}
});
}
private void initData() {
for (int i = 0; i < 3; i++) {
Fruit apple = new Fruit("苹果",R.drawable.apple);
mFruits.add(apple);
Fruit orange = new Fruit("橘子",R.drawable.orange);
mFruits.add(orange);
Fruit strawberry = new Fruit("草莓",R.drawable.strawberry);
mFruits.add(strawberry);
Fruit watermelon = new Fruit("西瓜",R.drawable.watermelon);
mFruits.add(watermelon);
Fruit lemon = new Fruit("柠檬",R.drawable.lemon);
mFruits.add(lemon);
Fruit pear = new Fruit("梨子",R.drawable.pear);
mFruits.add(pear);
Fruit kiwi = new Fruit("猕猴桃",R.drawable.kiwi);
mFruits.add(kiwi);
Fruit tomato = new Fruit("西红柿",R.drawable.tomato);
mFruits.add(tomato);
Fruit grape = new Fruit("葡萄",R.drawable.grape);
mFruits.add(grape);
}
}
} MyAdapter:
package com.example.arrayadapter2_listview;
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 java.util.List;
public class MyAdapter extends ArrayAdapter {
private int resourceId;
public MyAdapter(Context context, int textViewResourceId,
List objects) {
super(context, textViewResourceId, objects);
resourceId = textViewResourceId;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Fruit fruit = getItem(position);
View view;
ViewHolder viewHolder;
if (convertView == null) {
view = LayoutInflater.from(getContext()).inflate(resourceId, parent,
false);
viewHolder = new ViewHolder();
viewHolder.fruitImage = (ImageView) view.findViewById
(R.id.fruit_image);
viewHolder.fruitName = (TextView) view.findViewById (R.id.fruit_name);
view.setTag(viewHolder); // 将ViewHolder存储在View中
} else {
view = convertView;
viewHolder = (ViewHolder) view.getTag(); // 重新获取ViewHolder
}
viewHolder.fruitImage.setImageResource(fruit.getImageId());
viewHolder.fruitName.setText(fruit.getName());
return view;
}
class ViewHolder {
ImageView fruitImage;
TextView fruitName;
}
}
Fruit:
package com.example.arrayadapter2_listview;
public class Fruit {
private String name;
private int imageId;
public Fruit(String name, int imageId) {
this.name = name;
this.imageId = imageId;
}
public String getName() {
return name;
}
public int getImageId() {
return imageId;
}
}
activity_main:
fruit_item:
效果图：
传送门ListView的子类ExpandableListView：ExpandableListView控件的使用_敬往事一杯酒哈的博客-CSDN博客