Android开发笔记—Spinner的基础使用

Spinner为下拉列表，可以通过ArrayAdater数组适配器配置文字下拉列表，也可以通过SimpleAdater简单适配器配置图文下拉列表。这些控件都类似于ListView组件的使用，适配器详解具体参考Android开发笔记—ListView的基础使用
效果图


xml文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.jialin.spinnerdemo.MainActivity">

    <TextView
        android:id="@+id/text1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:text="简单适配器!" />

    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/text1"
        >
    </Spinner>
    <TextView
        android:id="@+id/text2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:layout_below="@id/spinner1"
        android:text="文字适配器!" />
    <Spinner
        android:id="@+id/spinner2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/text2"
        >
    </Spinner>
</RelativeLayout>

用于简单适配器的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">
<ImageView
    android:id="@+id/pic"
    android:layout_width="60dp"
    android:layout_height="60dp"
    android:src="@mipmap/ic_launcher"
    />
    <TextView
        android:id="@+id/text_ctiy"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:textSize="20sp"
        android:text="长沙"
        />
</LinearLayout>

java代码

package com.example.jialin.spinnerdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.SimpleAdapter;
import android.widget.Spinner;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MainActivity extends AppCompatActivity {
    private Spinner spinner1,spinner2;
    private TextView textView1,textView2;
    private ArrayAdapter<String>arrayAdapter;
    private String[]list = {"长沙","常德","株洲","湘潭"};
    private SimpleAdapter simpleAdapter;
    private List<Map<String, Object>> list_data;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView1 = (TextView) findViewById(R.id.text1);
        textView2 = (TextView) findViewById(R.id.text2);
        spinner1 = (Spinner) findViewById(R.id.spinner1);
        spinner2 = (Spinner) findViewById(R.id.spinner2);

        //新建一个简单适配器
        list_data = new ArrayList<Map<String, Object>>();
        simpleAdapter = new SimpleAdapter(this,getData(),R.layout.spinner_item,new String[]{"pic","text_ctiy"},new int[]{R.id.pic,R.id.text_ctiy});
        spinner1.setAdapter(simpleAdapter);
        //监听器
        spinner1.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                textView1.setText("你选择的是："+list[position]);
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {}
        });

        //新建一个数组适配器
        arrayAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list);
        //设置下拉样式
        arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner2.setAdapter(arrayAdapter);
        //监听器
        spinner2.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                textView2.setText("你选择的是："+arrayAdapter.getItem(position));
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {}
        });
    }
    //数据源
    public List<Map<String,Object>> getData() {
        for (int i = 0; i < list.length; i++){
            Map<String, Object>map = new HashMap<>();
            map.put("pic",R.mipmap.ic_launcher);
            map.put("text_ctiy",list[i]);
            list_data.add(map);
        }
        return list_data;
    }
}