下拉选择框练习
一、xml文件中定义下拉选择框
两种方式:
1.运用entries:android:entries="@array/cypte"
2.在java代码中运用适配器如下
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<Spinner
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/spinner"
>
</Spinner>
</RelativeLayout>
二、values中定义资源
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="ctype">
<item>全部</item>
<item>上海</item>
<item>杭州</item>
<item>北京</item>
<item>安徽</item>
</string-array>
</resources>
三、java代码中编写适配器
package com.example.acer.twicework;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
//下拉选择框
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] ctype = new String[]{"全部", "北京", "上海", "杭州", "安徽"}; //设置数组
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, ctype); //定义适配器
adapter.setDropDownViewResource(android.R.layout.simple_spinner_item); //设置下拉样式
Spinner spinner = (Spinner) findViewById(R.id.spinner); //获取下拉框
spinner.setAdapter(adapter); //为下拉框设置适配器
String str = spinner.getSelectedItem().toString(); //定义字符串str用于输出选择的选项
Toast.makeText(MainActivity.this, str, Toast.LENGTH_LONG).show(); //打印结果
}
}
运行结果
案例项目目录