Android 之 下拉框(Spinner)的使用

Spinner的使用，可以极大提高用户的体验性。当需要用户选择的时候，可以提供一个下拉列表将所有可选的项列出来。供用户选择。 

Demo如下，可以留作参考 

一、使用数组作为数据源 

1.新建一个android的工程 

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

<?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>

3.java代码

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 static final String[] m={"A型","B型","O型","AB型","其他"};
private TextView view ;
private Spinner spinner;
private ArrayAdapter<String> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.spinner);

view = (TextView) findViewById(R.id.spinnerText);
spinner = (Spinner) findViewById(R.id.Spinner01);
//将可选内容与ArrayAdapter连接起来
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,m);

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

//将adapter 添加到spinner中
spinner.setAdapter(adapter);

//添加事件Spinner事件监听  
spinner.setOnItemSelectedListener(new SpinnerSelectedListener());

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

}

//使用数组形式操作
class SpinnerSelectedListener implements OnItemSelectedListener{


public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
view.setText("你的血型是："+m[arg2]);
}


public void onNothingSelected(AdapterView<?> arg0) {
}
}
}

4、运行效果如下：

二、使用XML作为数据源 
1.新建一个android的工程 
2.在values文件夹下新建一个arryas.xml文件：声明一个TextView控件和一个Spinner控件，代码如下：

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="plantes">
<item>NOKIA</item>
<item>MOTO</item>
<item>HTC</item>
<item>LG</item>
<item>其他</item>
</string-array>
</resources>

3.java代码

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("你使用什么样的手机："+adapter2.getItem(arg2));
}


public void onNothingSelected(AdapterView<?> arg0) {

}

}
}

4、运行效果如下：

// 添加事件Spinner事件监听
spinner.setOnHierarchyChangeListener(new ViewGroup. OnHierarchyChangeListener() {

@Override
public void onChildViewRemoved(View parent, View child) {
// TODO Auto-generated method stub

}

@Override
public void onChildViewAdded(View parent, View child) {
// TODO Auto-generated method stub

}
});