如何修复此错误？我找不到任何可以帮助我的东西！代码片段将不胜感激！
sp2 的适配器在 sp1 的 onItemSelected 中设置的原因是因为我希望 sp2 的输出依赖于 sp1 中的选择。
日志猫：
08-05 16:36:24.856: D/dalvikvm(6606): GC_EXTERNAL_ALLOC freed 81K, 43% free 3119K/5379K, external 2770K/2773K, paused 28ms
08-05 16:36:25.707: D/AndroidRuntime(6606): Shutting down VM
08-05 16:36:25.707: W/dalvikvm(6606): threadid=1: thread exiting with uncaught exception (group=0x4001e560)
08-05 16:36:25.707: E/AndroidRuntime(6606): FATAL EXCEPTION: main
08-05 16:36:25.707: E/AndroidRuntime(6606): java.lang.NullPointerException
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:291)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.widget.AbsSpinner.setAdapter(AbsSpinner.java:113)
08-05 16:36:25.707: E/AndroidRuntime(6606): at com.madonk.louisiana.festivals.Region$1.onItemSelected(Region.java:107)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.widget.AdapterView.fireOnSelected(AdapterView.java:877)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.widget.AdapterView.access$200(AdapterView.java:42)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:843)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.os.Handler.handleCallback(Handler.java:587)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.os.Handler.dispatchMessage(Handler.java:92)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.os.Looper.loop(Looper.java:130)
08-05 16:36:25.707: E/AndroidRuntime(6606): at android.app.ActivityThread.main(ActivityThread.java:3821)
08-05 16:36:25.707: E/AndroidRuntime(6606): at java.lang.reflect.Method.invokeNative(Native Method)
08-05 16:36:25.707: E/AndroidRuntime(6606): at java.lang.reflect.Method.invoke(Method.java:507)
08-05 16:36:25.707: E/AndroidRuntime(6606): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-05 16:36:25.707: E/AndroidRuntime(6606): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-05 16:36:25.707: E/AndroidRuntime(6606): at dalvik.system.NativeStart.main(Native Method)
这是有问题的代码：
sp2.setAdapter(sc_cit_adp);
.java：
package com.madonk.louisiana.festivals;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
/**
* @author madonk
*
*/
public class Region extends Activity {
Spinner sp1,sp2,sp3;
ArrayAdapter<String> reg_adp,sw_cit_adp,sc_cit_adp,sw_lake_charles_adp,sw_iowa_adp,sc_lafayette_adp,sc_gueydan_adp;
List<String> regions,sw_cities,sc_cities,sw_lake_charles,sw_iowa,sc_lafayette,sc_gueydan;
int pos;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_region);
String[] regionsArray = getResources().getStringArray(R.array.regions_array);
regions = new ArrayList<String>(Arrays.asList(regionsArray));
String[] swcitiesArray = getResources().getStringArray(R.array.southwest_cities_array);
sw_cities = new ArrayList<String>(Arrays.asList(swcitiesArray));
String[] swiowaArray = getResources().getStringArray(R.array.sw_iowa_array);
sw_iowa = new ArrayList<String>(Arrays.asList(swiowaArray));
String[] swlakecharlesArray = getResources().getStringArray(R.array.sw_lake_charles_array);
sw_lake_charles = new ArrayList<String>(Arrays.asList(swlakecharlesArray));
String[] sclafayetteArray = getResources().getStringArray(R.array.sc_lafayette_array);
sc_lafayette = new ArrayList<String>(Arrays.asList(sclafayetteArray));
String[] scgueydanArray = getResources().getStringArray(R.array.sc_gueydan_array);
sc_gueydan = new ArrayList<String>(Arrays.asList(scgueydanArray));
sp1= (Spinner) findViewById(R.id.regions_spinner);
sp2= (Spinner) findViewById(R.id.city_spinner);
sp3= (Spinner) findViewById(R.id.festival_spinner);
reg_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,regions);
reg_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sp1.setAdapter(reg_adp);
sw_cit_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,sw_cities);
sw_cit_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sw_lake_charles_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,sw_lake_charles);
sw_lake_charles_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sw_iowa_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,sw_iowa);
sw_iowa_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sc_cit_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,sc_cities);
sc_cit_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sc_lafayette_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,sc_lafayette);
sc_lafayette_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sc_gueydan_adp=new ArrayAdapter<String> (this,android.R.layout.simple_dropdown_item_1line,sc_gueydan);
sc_gueydan_adp.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
sp1.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
String reg_select = (sp1.getSelectedItem().toString());
if (reg_select.contentEquals("Southwest")){
sp2.setAdapter(sw_cit_adp);
sp2.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
String sw_cit_select = (sp2.getSelectedItem().toString());
if (sw_cit_select.contentEquals("Lake Charles")){
sp3.setAdapter(sw_lake_charles_adp); }
else if (sw_cit_select.contentEquals("Iowa")){
sp3.setAdapter(sw_iowa_adp); }
;}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
};});}
else if (reg_select.contentEquals("South Central")){
sp2.setAdapter(sc_cit_adp);
sp2.setOnItemSelectedListener(new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
String sc_cit_select = (sp2.getSelectedItem().toString());
if (sc_cit_select.contentEquals("Lafayette")){
sp3.setAdapter(sc_lafayette_adp); }
else if (sc_cit_select.contentEquals("Gueydan")){
sp3.setAdapter(sc_gueydan_adp); }
;}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
};});}
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});}}