Android学习(15)Adapter_适配器
Adapter:适配器。
系统提供的四个适配器:
- ArrayAdapter:用于字符串数组String[]
- SimpleAdapter:用于列表List
- SimpleCursorAdapter:用于数据库Cursor
主要方法:
- getCount
- getItem
- getItemId
- getView
自定义一个适配器
1.自定义一个视图imageview.xml
imageview.xml
<?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="horizontal">
<ImageView
android:id="@+id/iiv"
android:layout_width="48dp"
android:layout_height="52dp"
android:src="@drawable/nazi"/>
<TextView
android:id="@+id/tvAd"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
2.布局ListView显示视图
<?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">
<ListView
android:id="@+id/lvAd"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
3.自定义一个适配器MyAdapter.java
MyAdapter.java
public class MyAdapter extends BaseAdapter {
private Context context;
private String data[];
public DiyAdapter(Context context,String data[]) {
this.context = context;
this.data = data;
}
//当前你数据的长度
@Override
public int getCount() {
return data.length;
}
//获得当前每一条数据的Item
@Override
public Object getItem(int position) {
return data[position];
}
//获取每一条数据的id
@Override
public long getItemId(int position) {
return position;
}
//需要加载的视图
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null){
//加载一个视图
convertView = LayoutInflater.from(context).inflate(R.layout.imageview,null);
}
TextView tv = (TextView)convertView.findViewById(R.id.tvAd);
tv.setText(data[position]);
return convertView;
}
}
4.Activity中配置适配器
public class AdapterActivity extends AppCompatActivity {
private ListView lv;
private DiyAdapter adapter;
private String data[]={"成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都","成都",};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_adapter);
lv = (ListView)findViewById(R.id.lvAd);
//加载adapter
adapter = new DiyAdapter(this, data);
//绑定adapter
lv.setAdapter(adapter);
}
}
声明:
1.知识点来源于《网易云课堂》——《Android基础视频教程》
2.本文只用于本人自身学习记录,如有侵权,请立即通知本人更改或删除
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