Android Spinner

下拉列表 Spinner。

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。

1：新建一个SpinnerDemo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:orientation
=
"vertical"
    android:layout_width
=
"fill_parent"
    android:layout_height
=
"fill_parent"
    >
<
TextView
 
android:text
=
"@+id/TextView01"
 
android:id
=
"@+id/TextView01"
 
android:layout_width
=
"wrap_content"
 
android:layout_height
=
"wrap_content"
>
</
TextView
>
<
Spinner
 
android:id
=
"@+id/Spinner01"
 
android:layout_width
=
"wrap_content"
 
android:layout_height
=
"wrap_content"
>
</
Spinner
>
</
LinearLayout
>

3：主代码如下：

package
 com.rocky.studio.ch427;
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.TextView;
public
 
class
 SpinnerDemo 
extends
 Activity {


    private
 
static
 
final
 String[] m_Countries={
"o型"
,
"A型"
,
"B型"
,
"AB型"
,
"其他"
};
    private
 TextView m_txtView;
    private
 Spinner m_Spinner;
    private
 ArrayAdapter<String> adapter;

    /** Called when the activity is first created. */
    @Override
    public
 
void
 onCreate(Bundle savedInstanceState) {
        super
.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        m_txtView=(TextView)this
.findViewById(R.id.TextView01);
        m_Spinner=(Spinner)this
.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_Countries);

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

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

        //添加事件Spinner事件监听
        m_Spinner.setOnItemSelectedListener(m_SpinnerListener);

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

    }
    private
 Spinner.OnItemSelectedListener m_SpinnerListener=
new
 Spinner.OnItemSelectedListener()
    {
        public
 
void
 onItemSelected(AdapterView<?> arg0, View arg1, 
int
 arg2,
                long
 arg3) {
            // TODO Auto-generated method stub
            m_txtView.setText("你的血型是："
+m_Countries[arg2]);
            //arg0.setVisibility(View.VISIBLE);

        }

        public
 
void
 onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub

        }
    };
}