初识Spinner

Spinner是个下拉列表框，与listview一样，也是adapterView的一个间接子类，是一个显示数据的窗口。

 <Spinner
            android:id="@+id/spinner1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:entries="@array/spinner_name"
            android:prompt="@string/hello_world" />

为Spinner设定数据来源

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="spinner_name">
        <item>Mercury</item>
        <item>Venus</item>
        <item>Earth</item>
        <item>Mars</item>
        <item>Jupiter</item>
        <item>Saturn</item>
        <item>Uranus</item>
        <item>Neptune</item>
    </string-array>
</resources>

为Spinner设置adapter并添加事件响应

     public void showSpinner() {
         Spinner spinner = (Spinner) findViewById(R.id.spinner2);
         //The simple_spinner_item layout is provided by the platform and is the default layout you should use unless you'd like to define your own layout for the spinner's appearance.
         SpinnerAdapter spinnerAdapter = ArrayAdapter.createFromResource(FormActivity.this, R.array.spinner_name,android.R.layout.simple_spinner_item);         

　　 　　　　　// Specify the layout to use when the list of choices appears | Sets the layout resource to create the drop down views.
　　　 　　　　spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

         spinner.setAdapter(spinnerAdapter);
         spinner.setOnItemSelectedListener(new OnItemSelectedListener() {

             @Override
             public void onItemSelected(AdapterView<?> parent, View view,
                     int position, long id) {
                 // TODO Auto-generated method stub

                 Log.i(TAG,
                         "showSpinner : onItemSelected "
                                 + ((TextView) view).getText() + ":position "
                                 + id);
             }

             @Override
             public void onNothingSelected(AdapterView<?> parent) {
                 // TODO Auto-generated method stub
                 Log.i(TAG, "showSpinner : onNothingSelected ");
             }
         });

     }