效果圖:
ListView 與 ArrayAdapter 之間的配合:
activity_main.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_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<ListView
android:id="@+id/ls_view"
android:layout_width="match_parent"
android:layout_height="match_parent"></ListView>
</LinearLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = findViewById(R.id.ls_view);
// 創造資料源
String[] data = {"冰激淩","奶茶","芒果","西瓜","蕃茄炒蛋","剁椒魚頭","雞翅","冰激淩","奶茶","芒果","西瓜","蕃茄炒蛋","剁椒魚頭","雞翅","冰激淩","奶茶","芒果","西瓜","蕃茄炒蛋","剁椒魚頭","雞翅"};
/**
* 建立ArrayAdapter 擴充卡 — 把資料源放入擴充卡中
* 第一個參數是: context
* 第二個參數是: 每一條資料顯示的布局item,這裡用系統預設的就行
* 第三個參數是: 放入剛剛建立好的資料源
*/
ArrayAdapter adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data);
listView.setAdapter(adapter); // 再讓清單與擴充卡産生聯系
}
}
ListView 與 SimpleAdapter 之間的配合:
activity_main.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_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context=".MainActivity">
<ListView
android:id="@+id/lv_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"></ListView>
</LinearLayout>
ly_item.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_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context=".MainActivity">
<ImageView
android:id="@+id/img_view"
android:layout_width="80dp"
android:layout_height="80dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/tv_name"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_marginLeft="40dp"
android:textSize="25dp"
android:text="你好"
/>
<TextView
android:id="@+id/tv_info"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_marginTop="10dp"
android:layout_marginLeft="40dp"
android:textSize="25dp"
android:text="你好"></TextView>
</LinearLayout>
</LinearLayout>
MainActivity.java:
public class MainActivity extends AppCompatActivity {
private String[] name = {"狐狸","玫瑰","國王"}; // 名字
private String[] info = {"聰明的狐狸","帶刺的花兒","沒有一個臣民"}; // 介紹
private int[] image = {R.mipmap.ic_one,R.mipmap.ic_two,R.mipmap.ic_three}; // 每一個item對應的圖示
List<Map<String,Object>> list = new ArrayList<>(); // 建立 資料源 list
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 給資料源裝配資料
for (int i=0;i<name.length;i++){
Map<String,Object> map = new HashMap<>(); // 在建立一個map集合
map.put("image",image[i]);
map.put("name",name[i]);
map.put("info",info[i]);
list.add(map); // 将每一組map對象的值,加入到list集合中
}
/**
* 建立 SimpleAdapter 擴充卡
* 第一個參數: context
* 第二個參數: 放入資料源
* 第三個參數: 每一個item的布局
* 第四個參數: 建立map的鍵對象,并放入相應的值,因為要從資料源中識别對應值,每一個鍵對象對應着一個值對象
* 第五個參數: 建立一個int對象,放入item布局中 每一個控件對應的id,這個id與剛才的鍵對象位置要對應
*/
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,list,R.layout.ly_item,new String[]{"image","name","info"},new int[]{R.id.img_view,R.id.tv_name,R.id.tv_info});
// 得到listView 對象
ListView listView = findViewById(R.id.lv_list);
// 讓listview 與 SimpleAdapter 擴充卡産生聯系
listView.setAdapter(adapter);
}
}
ListView 與 BaseAdapter 之間的配合【推薦】:
activity_main.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_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context=".MainActivity">
<ListView
android:id="@+id/lv_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"></ListView>
</LinearLayout>
ly_item.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_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context=".MainActivity">
<ImageView
android:id="@+id/img_view"
android:layout_width="100dp"
android:layout_height="100dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="100dp"
android:orientation="vertical">
<TextView
android:id="@+id/tv_name"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_marginLeft="40dp"
android:textSize="25dp"
android:text="你好"
/>
<TextView
android:id="@+id/tv_info"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_marginTop="10dp"
android:layout_marginLeft="40dp"
android:textSize="25dp"
android:text="你好"></TextView>
</LinearLayout>
</LinearLayout>
MainActivity.java:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = findViewById(R.id.lv_list);
List<CostBean> costBeanList = new ArrayList<>(); //建立封裝好的bean對象
// 裝配資料源
costBeanList.add(new CostBean(R.mipmap.ic_one,"狐狸","聰明的狐狸"));
costBeanList.add(new CostBean(R.mipmap.ic_two,"玫瑰","帶刺的花兒"));
costBeanList.add(new CostBean(R.mipmap.ic_three,"國王","沒有一個臣民"));
// 因為 MyAdapter 繼承了 BaseAdapter,是以這裡直接讓 listView 與 Myadapter産生聯系
listView.setAdapter(new MyAdapter(this,costBeanList));
}
}
CostBean.java:
**
* CostBean —— 封裝資料源
*/
public class CostBean {
private int imgId;
private String name;
private String info;
public CostBean(int imgId, String name, String info) {
this.imgId = imgId;
this.name = name;
this.info = info;
}
public int getImgId() {
return imgId;
}
public String getName() {
return name;
}
MyAdapter.java:
**
* BaseAdapter —— 擴充卡管理資料源
*/
public class MyAdapter extends BaseAdapter {
private List<CostBean> costBeanList;
private LayoutInflater inflater;
// 通過構造方法關聯資料源與擴充卡
public MyAdapter(Context context,List<CostBean> costBeanList) {
this.costBeanList = costBeanList;
// context:要使用目前的Adapter的界面對象mInflater:布局 裝載器對象
this.inflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return costBeanList.size();
}
@Override
public Object getItem(int position) {
return costBeanList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
//第一次建立view即可,以免給程式帶來太多負擔
if (convertView == null){
holder = new ViewHolder();
// 由于我們隻需要将XML轉化為View,并不涉及到具體的布局,是以第二個參數通常設定為null
convertView = inflater.inflate(R.layout.ly_item,null);
holder.imageView = convertView.findViewById(R.id.img_view);
holder.title = convertView.findViewById(R.id.tv_name);
holder.content = convertView.findViewById(R.id.tv_info);
//這句話的意思就是,讓convertView與holder産生關聯,通過set儲存在Tag中
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
//通過getTag,取出上面綁定的holder,以免多次綁定,造成資源浪費
}
//設定控件的資料,可以了解為從封裝的資料中取出一個一個對應的值
CostBean costBean = costBeanList.get(position);
holder.imageView.setImageResource(costBean.getImgId());
holder.title.setText(costBean.getName());
holder.content.setText(costBean.getInfo());
return convertView;
}
class ViewHolder{
public ImageView imageView;
public TextView title;
public TextView content;
}
}