android下拉菜单spinner的使用方法

Spinner控件也是一种列表类型的控件，它的继承关系如下：

Java.lang.Object

↳ Android.view.View

↳ android.view.ViewGroup

↳ android.widget.AdapterView<Textends android.widget.Adapter>

↳ android.widget.AbsSpinner

↳ android.widget.Spinner

android.widget.Spinner继承了android.view.ViewGroup类。

在Android的UI开发中，Spinner(下拉列表)总是可以用到的，一个简单的自定义Spinner制作我们只需要记住这重要的五步，一个Spinner就可以应用而生了。

(1)新建一个android工程，名称为Spinner。同时建一个Activity，名称为SpinnerActivity。



(2)修改res/layout/main.xml
[html] view plain copy print?<?xml version=“1.0” encoding=“utf-8”?>
<LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
android:orientation=“vertical”
android:layout_width=“fill_parent”
android:layout_height=“fill_parent”
>
<TextView
android:id = “@+id/TextView_city”
android:layout_width = “wrap_content”
android:layout_height = “wrap_content”
android:text = “所在城市：”
/>
<!– 定义一个城市信息下拉菜单–>
<Spinner
android:id = “@+id/Spinner_city”
android:layout_width = “wrap_content”
android:layout_height =“wrap_content” >
</Spinner >
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id = "@+id/TextView_city"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:text = "所在城市："
/>
<!-- 定义一个城市信息下拉菜单-->
<Spinner
android:id = "@+id/Spinner_city"
android:layout_width = "wrap_content"
android:layout_height ="wrap_content" >
</Spinner >
</LinearLayout>

(3)SpinnerActivity.java 代码。
[java] view plain copy print?package cn.com;

import java.util.ArrayList;
import java.util.List;

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

public class SpinnerActivity extends Activity {
/** Called when the activity is first created. */
private List<String> list = new ArrayList<String>();
private TextView myTextView;
private Spinner mySpinner;
private ArrayAdapter<String> adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//第一步：添加一个下拉列表项的list，这里添加的项就是下拉列表的菜单项
list.add(”北京”);
list.add(”上海”);
list.add(”深圳”);
list.add(”福州”);
list.add(”厦门”);
myTextView = (TextView)findViewById(R.id.TextView_city);
mySpinner = (Spinner)findViewById(R.id.Spinner_city);
//第二步：为下拉列表定义一个适配器，这里就用到里前面定义的list。
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, list);
//第三步：为适配器设置下拉列表下拉时的菜单样式。
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
//第四步：将适配器添加到下拉列表上
mySpinner.setAdapter(adapter);
//第五步：为下拉列表设置各种事件的响应，这个事响应菜单被选中
mySpinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
// TODO Auto-generated method stub
/* 将所选mySpinner 的值带入myTextView 中*/
myTextView.setText(”您选择的是：”+ adapter.getItem(arg2));
/* 将mySpinner 显示*/
arg0.setVisibility(View.VISIBLE);
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
myTextView.setText(”NONE”);
arg0.setVisibility(View.VISIBLE);
}
});
/*下拉菜单弹出的内容选项触屏事件处理*/
mySpinner.setOnTouchListener(new Spinner.OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
/**
*
*/
return false;
}
});
/*下拉菜单弹出的内容选项焦点改变事件处理*/
mySpinner.setOnFocusChangeListener(new Spinner.OnFocusChangeListener(){
public void onFocusChange(View v, boolean hasFocus) {
// TODO Auto-generated method stub

}
});
}
}

package cn.com;

import java.util.ArrayList;
import java.util.List;

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

public class SpinnerActivity extends Activity {
/** Called when the activity is first created. */
private List<String> list = new ArrayList<String>();
private TextView myTextView;
private Spinner mySpinner;
private ArrayAdapter<String> adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//第一步：添加一个下拉列表项的list，这里添加的项就是下拉列表的菜单项
list.add("北京");
list.add("上海");
list.add("深圳");
list.add("福州");
list.add("厦门");
myTextView = (TextView)findViewById(R.id.TextView_city);
mySpinner = (Spinner)findViewById(R.id.Spinner_city);
//第二步：为下拉列表定义一个适配器，这里就用到里前面定义的list。
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, list);
//第三步：为适配器设置下拉列表下拉时的菜单样式。
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
//第四步：将适配器添加到下拉列表上
mySpinner.setAdapter(adapter);
//第五步：为下拉列表设置各种事件的响应，这个事响应菜单被选中
mySpinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
// TODO Auto-generated method stub
/* 将所选mySpinner 的值带入myTextView 中*/
myTextView.setText("您选择的是："+ adapter.getItem(arg2));
/* 将mySpinner 显示*/
arg0.setVisibility(View.VISIBLE);
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
myTextView.setText("NONE");
arg0.setVisibility(View.VISIBLE);
}
});
/*下拉菜单弹出的内容选项触屏事件处理*/
mySpinner.setOnTouchListener(new Spinner.OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
/**
*
*/
return false;
}
});
/*下拉菜单弹出的内容选项焦点改变事件处理*/
mySpinner.setOnFocusChangeListener(new Spinner.OnFocusChangeListener(){
public void onFocusChange(View v, boolean hasFocus) {
// TODO Auto-generated method stub

}
});
}
}

运行结果如下图所示：