Android 之 下拉框(Spinner)的简单使用

1. 工程的layout.xml文件如下：声明一个TextView控件和一个Spinner控件

[java]
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<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical"

>
<TextView android:id="@+id/spinnerText"

android:layout_width="fill_parent"

android:layout_height="wrap_content"></TextView>

<Spinner android:id="@+id/Spinner01"

android:layout_width="fill_parent"

android:layout_height="wrap_content"></Spinner>

</LinearLayout>

[xhtml]
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<?xml
version="1.0"
encoding="utf-8"?>

<resources>

<string-array
name="plantes">

<item>中国</item>

<item>美国</item>

<item>日本</item>

<item>英国</item>

<item>法国</item>

</string-array>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="plantes">
<item>中国</item>
<item>美国</item>
<item>日本</item>
<item>英国</item>
<item>法国</item>
</string-array>
</resources>

3. 主类

[java]
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import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemSelectedListener;

import android.widget.ArrayAdapter;

import android.widget.Spinner;

import android.widget.TextView;

public class SpinnerActivity
extends Activity {

private TextView view2;

private Spinner spinner2;

private ArrayAdapter adapter2;

@Override
protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.spinner);

spinner2 = (Spinner) findViewById(R.id.spinner02);

view2 = (TextView) findViewById(R.id.spinnerText02);

//将可选内容与ArrayAdapter连接起来

adapter2 = ArrayAdapter.createFromResource(this, R.array.plantes, android.R.layout.simple_spinner_item);

//设置下拉列表的风格
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

//将adapter2 添加到spinner中

spinner2.setAdapter(adapter2);

//添加事件Spinner事件监听

spinner2.setOnItemSelectedListener(new SpinnerXMLSelectedListener());

//设置默认值

spinner2.setVisibility(View.VISIBLE);

}

//使用XML形式操作
class SpinnerXMLSelectedListener
implements OnItemSelectedListener{

public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2,
long arg3) {

view2.setText("你来自："+adapter2.getItem(arg2));

}

public void onNothingSelected(AdapterView<?> arg0) {

}

}
}

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

public class SpinnerActivity extends Activity {

private TextView view2;
private Spinner spinner2;
private ArrayAdapter adapter2;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.spinner);

spinner2 = (Spinner) findViewById(R.id.spinner02);
view2 = (TextView) findViewById(R.id.spinnerText02);

//将可选内容与ArrayAdapter连接起来
adapter2 = ArrayAdapter.createFromResource(this, R.array.plantes, android.R.layout.simple_spinner_item);

//设置下拉列表的风格
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

//将adapter2 添加到spinner中
spinner2.setAdapter(adapter2);

//添加事件Spinner事件监听
spinner2.setOnItemSelectedListener(new SpinnerXMLSelectedListener());

//设置默认值
spinner2.setVisibility(View.VISIBLE);

}

//使用XML形式操作
class SpinnerXMLSelectedListener implements OnItemSelectedListener{
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
view2.setText("你来自："+adapter2.getItem(arg2));
}

public void onNothingSelected(AdapterView<?> arg0) {

}

}
}

setDropDownViewResource 主要是设置 User 点击 Spinner 后出现的下拉菜单样式， android 亦提供两种基本的样式：

android.R.layout.simple_spinner_item ： TextView 的下拉菜单。

android.R.layout.simple_spinner_dropdown_item ：除了有 TextView ，右边有 radio 的下拉菜单。

当然，用户也可以自定义这个样式