android控件——Spinner（下拉框）

效果图：

实现代码：

xml：

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

java：

import android.os.Bundle;  
import android.support.v7.app.AppCompatActivity;  
import android.view.View;  
import android.widget.AdapterView;  
import android.widget.ArrayAdapter;  
import android.widget.AutoCompleteTextView;  
import android.widget.SimpleAdapter;  
import android.widget.Spinner;  
import android.widget.Toast;  
  
import java.util.ArrayList;  
import java.util.HashMap;  
import java.util.List;  
import java.util.Map;  
  
/**  
 * Created by Administrator on 2017/6/8 0008.  
 */  
  
public class SpinnerActivity extends AppCompatActivity {  
  
  
    private Spinner s_main_spinner;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        s_main_spinner = (Spinner) findViewById(R.id.s_main_spinner);  
        //给下拉列表设置适配器  
        final String provinces[]={"湖南省","河南省","海南省"};  
        int images[]={R.drawable.dog,R.drawable.elephant,R.drawable.fox};  
  
        List<Map<String,Object>> list=new ArrayList<>();  
        for (int i = 0; i < provinces.length; i++) {  
            Map<String,Object> map=new HashMap<>();  
            map.put("title",provinces[i]);  
            map.put("image",images[i]);  
            list.add(map);  
        }  
  
        //适配器  
        //SimpleAdapter  
        SimpleAdapter adapterSpinner=new SimpleAdapter(this,list,android.R.layout.activity_list_item,new String[]{"title","image"},new int[]{android.R.id.text1,android.R.id.icon});  
        s_main_spinner.setAdapter(adapterSpinner);  
  
        //给下列列表设置选择事件  
        s_main_spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {  
            @Override  
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {  
                Toast.makeText(SpinnerActivity.this, provinces[i], Toast.LENGTH_SHORT).show();  
            }  
            @Override  
            public void onNothingSelected(AdapterView<?> adapterView) {  
  
            }  
        });  
    }  
}