在屏幕中显示下拉表框

<?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:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="Spinner_1"    />    <Spinner  android:id="@+id/spinner_1"       android:layout_width="fill_parent"       android:layout_height="wrap_content"       android:drawSelectorOnTop="false"/><TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="Spinner_2 From arrays xml file"    /> <Spinner  android:id="@+id/spinner_2"       android:layout_width="fill_parent"       android:layout_height="wrap_content"       android:drawSelectorOnTop="false"/>     <TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="Myself"    /> <Spinner  android:id="@+id/spinner_3"       android:layout_width="fill_parent"       android:layout_height="wrap_content"       android:drawSelectorOnTop="false"/></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><!--/* //device/apps/common/assets/res/any/layout/simple_spinner_item.xml**** Copyright 2006, The Android Open Source Project**** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ****     http://www.apache.org/licenses/LICENSE-2.0 **** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License.*/--><TextView xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@android:id/text1"    style="?android:attr/spinnerItemStyle"    android:singleLine="true"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:ellipsize="marquee" />

<?xml version="1.0" encoding="utf-8"?><!--/* //device/apps/common/assets/res/any/layout/simple_spinner_item.xml**** Copyright 2008, The Android Open Source Project**** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ****     http://www.apache.org/licenses/LICENSE-2.0 **** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License.*/--><CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@android:id/text1"    style="?android:attr/spinnerDropDownItemStyle"    android:singleLine="true"    android:layout_width="match_parent"    android:layout_height="?android:attr/dropdownListPreferredItemHeight"    android:ellipsize="marquee" />

<?xml version="1.0" encoding="utf-8"?><resources>    <!-- Used in Spinner/spinner_2.java -->    <string-array name="countries">        <item>AA</item>        <item>BB</item>        <item>CC</item>        <item>DD</item>        <item>EE</item>        <item>FF</item>    </string-array></resources>

package m.usewidget;import java.util.ArrayList;import java.util.List;import m.usewidget.R;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.ArrayAdapter;import android.widget.Button;import android.widget.CheckBox;import android.widget.EditText;import android.widget.Spinner;import android.widget.TextView;public class SpinnerActivity extends Activity {Spinner spinner_c;Spinner spinner_2;Spinner spinner_3;private ArrayAdapter<String> aspnCountries;private List<String> allcountries;/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setTitle("SpinnerActivity");setContentView(R.layout.spinner);find_and_modify_view();}private static final String[] mCountries = { "AA" ,"BB", "CC","DD", "EE", "FF" };private void find_and_modify_view() {spinner_c = (Spinner) findViewById(R.id.spinner_1);allcountries = new ArrayList<String>();for (int i = 0; i < mCountries.length; i++) {allcountries.add(mCountries[i]);}aspnCountries = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, allcountries);aspnCountries.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);spinner_c.setAdapter(aspnCountries);spinner_2 = (Spinner) findViewById(R.id.spinner_2);        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(                this, R.array.countries, android.R.layout.simple_spinner_item);        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);        spinner_2.setAdapter(adapter);                spinner_3 = (Spinner) findViewById(R.id.spinner_3);        ArrayAdapter< String> adapter1 =            new ArrayAdapter< String>( this,            android.R.layout.simple_spinner_item);            adapter1.add("red");            adapter1.add("green");            adapter1.add("yellow");            adapter1.add("black");            adapter1.add("write");            adapter1.add("blue");                         adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);                         spinner_3.setAdapter(adapter1);} }