Android 控件学习 之 Spinner

Android 控件学习 之 Spinner

给大家展示一个Android spinner控件的简单使用

package com.niit.spinner;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import android.widget.AdapterView.OnItemSelectedListener;

public class A_20111026_SpinnerActivity extends Activity {

    private Spinner spinner = null; // 定义一个Spinner控件

    private ArrayAdapter<CharSequence> adapter = null; // 定义一个数据适配器，用来将里面的数据显示在Spinner中

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        spinner = (Spinner) this.findViewById(R.id.spinner);

        // 第一个参数是 当前Activity的对象
        // 第二个参数 是定义的数据
        // 第三个参数是 android系统内的 布局文件
        adapter = ArrayAdapter.createFromResource(this, R.array.planets_array,
                android.R.layout.simple_spinner_item);

        // 显示在下拉列表的数据项
        adapter
                .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // 设置数据源
        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
               
                Toast.makeText(parent.getContext(),  
                        parent.getItemAtPosition(position).toString(), 1)
                        .show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                // TODO Auto-generated method stub

            }

        });
    }

}

AndroidManifest.xml 文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.niit.spinner"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />

    <application android:icon="@drawable/icon" android:label="@string/planet_prompt">
        <activity android:name=".A_20111026_SpinnerActivity"
                  android:label="@string/planet_prompt">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

main.xml 文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:padding="10dip"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dip"
        android:text="@string/planet_prompt"
    />
    <Spinner
        android:id="@+id/spinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:prompt="@string/planet_prompt"
    />
</LinearLayout>

string.xml文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="planet_prompt">Choose a planet</string>
    <string-array name="planets_array">
        <item>Mercury</item>
        <item>Venus</item>
        <item>Earth</item>
        <item>Mars</item>
        <item>Jupiter</item>
        <item>Saturn</item>
        <item>Uranus</item>
        <item>Neptune</item>
    </string-array>
</resources>