我有一个 Activity ，我想显示一个没有按钮和元素列表的 AlertDialog。 问题是，如果我显示它，我会收到此错误:
Java.lang.NullPointerException at android.widget.createViewFromResource(ArrayAdapter.java 394)...
这是我的代码:
public class ContactsActivity extends BasicListActivity implements TextWatcher, DialogInterface.OnClickListener {
protected static final String NAMES_SHARED_PREF = "names_shared_pref";
protected static final String LEMON_SHARED_PREF = "lemon_shared_pref";
protected EditText search_bar;
protected ImageButton search_button;
ProgressDialog diag;
protected ArrayList<String> source = new ArrayList<String>();
protected ArrayList<String> names_result = new ArrayList<String>(); // i risultati di una ricerca
protected ArrayList<Boolean> lemonSims = new ArrayList<Boolean>();
protected ArrayList<Boolean> lemon_result = new ArrayList<Boolean>(); // per i risultati della ricerca
protected ServerInterface server;
String empty_message;
protected String script_name = "app_autocomplete.php";
protected AlertDialog.Builder builder;
protected String my_number ="";
protected String[] numbers; //viene usato per scegliere il numero dei contatti multipli
protected int popup_pos = 0;
/*============================================================= METHODS ================================================================*/
/**
* ON CREATE
* se la mainactivity non ha già le azioni nella savedInstanceState lancia una asynctask per ottenerle
*/
@Override
public void onCreate(Bundle savedInstanceState) {
this.setContentView(R.layout.search);
Bundle extras = this.getIntent().getExtras();
if (extras != null){
if (extras.containsKey(SmsChat.MY_PHONE)) my_number = extras.getString(SmsChat.MY_PHONE);
}
search_bar = (EditText) findViewById(R.id.search_bar);
search_button = (ImageButton) findViewById(R.id.search_button);
search_bar.addTextChangedListener(this);
listview = (ListView) findViewById(android.R.id.list);
diag = new ProgressDialog(ContactsActivity.this);
diag.setMessage(getResources().getString(R.string.updating));
super.onCreate(savedInstanceState);
getActionBar().setTitle(this.getResources().getString(R.string.contacts));
builder = new AlertDialog.Builder(this);
search_bar.setOnEditorActionListener(new OnEditorActionListener(){
@Override
public boolean onEditorAction(TextView v, int actionId,
KeyEvent event) {
setContents(search(v.getText().toString()));
return true;
}
});
search_button.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v) {
setContents(search(search_bar.getText().toString()));
}
});
listview.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> l, View v, final int position,
long id) {
ContactsInterface con = new ContactsInterface();
numbers = con.getContactNumberByDisplayName(names_result.get(position), ContactsActivity.this);
popup_pos = position;
if (numbers.length >1)
{
builder.setTitle(R.string.phone_numbers);
builder.setItems(numbers , new PopUpClickListener());
AlertDialog dialog = builder.create();
dialog.show();
}else{
startChat(numbers,position, 0);
}
}
});
}
@Override
public void setup(){
GetContacts gettask = new GetContacts();
gettask.execute("");
}
public void setContents(ArrayList<String> names){
if (names == null) return;
setContent(names, lemon_result);
}
/**
* SET CONTENT
*
* */
public void setContent(ArrayList<String> data, ArrayList<Boolean> lemonSims){
if (lemonSims.size() != data.size()){
lemonSims.clear();
for (int i=0; i<data.size();i++){
lemonSims.add(false);
}
}
if (data.size()>0){
ContactsAdapter adpt = new ContactsAdapter(data, lemonSims, this);
listview.setAdapter(adpt);
adpt.notifyDataSetChanged();
}
else{
setEmptyLayout();
}
}
/**
* SEARCH
* @param pattern
* @return
*/
public ArrayList<String> search(String pattern){
ArrayList<String> res = new ArrayList<String>();
ArrayList<Boolean> sims = new ArrayList<Boolean>();
if (source == null) return null;
if (pattern.length() <2){
names_result = source;
lemon_result = lemonSims;
return source;
}
for (int i=0; i<source.size();i++){
if (source.get(i).toLowerCase(Locale.US).contains(pattern.toLowerCase(Locale.US))){
res.add(source.get(i));
sims.add(lemonSims.get(i));
}
}
names_result = res;
lemon_result = sims;
return res;
}
@Override
public void afterTextChanged(Editable arg0) {
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
}
@Override
public void onTextChanged(CharSequence s, int arg1, int arg2, int arg3) {
setContents(search(s.toString()));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.contacts_menu, menu);
return true;
}
/**
* ON OPTION ITEM SELECTED
* associa un'azione ad ogni oggetto dell'action bar
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Pass the event to ActionBarDrawerToggle, if it returns
// true, then it has handled the app icon touch event
switch (item.getItemId()) {
case R.id.action_writenumber:
{
Intent intent = new Intent(this, SmsChat.class);
intent.putExtra(SmsChat.MY_PHONE, my_number);
startActivity(intent);
finish();
return true;
}
case R.id.action_update:{
diag.show();
GetContacts task = new GetContacts();
task.execute("update");
return true;
}
}
return super.onOptionsItemSelected(item);
}
/**
* GET CONTACTS TASK
* @author pc
*
*/
protected class GetContacts extends AsyncTask<String, Void, Boolean>{
@Override
protected void onPreExecute(){
super.onPreExecute();
diag.show();
}
@Override
protected Boolean doInBackground(String... params) {
/**
* I contatti sono caricati in un'altra attività
*/
if (params[0].equalsIgnoreCase("update")){
ContactsInterface con = new ContactsInterface();
con.loadFromPhone(ContactsActivity.this);
}
names_result = ContactsInterface.getContactsNames();
source = names_result;
lemonSims.clear();
lemonSims = ContactsInterface.getContactsLemon();
if (lemonSims.size() != source.size() || params[0].equalsIgnoreCase("update")) {
if (AppUtils.isOnline(ContactsActivity.this)){
CheckOnlineTask task = new CheckOnlineTask();
task.execute("");
}else {
lemonSims.clear();
for (int i=0; i<source.size();i++){
lemonSims.add(false);
}
lemon_result = lemonSims;
return true;
}
} else {
lemon_result = lemonSims;
return true;
}
return false;
}
@Override
protected void onPostExecute(Boolean success){
if (success){
ContactsActivity.this.setContents(source);
diag.hide();
}
}
}
/**
* CHECK LEMONSIM TASK
* AsyncTask che fa partire lo stream
* @author pc
*
*/
protected class CheckOnlineTask extends AsyncTask<String, Void, Boolean> {
JSONArray jobject = new JSONArray();
@Override
protected Boolean doInBackground(String... params) {
ServerInterface server = new ServerInterface();
ContactsInterface con = new ContactsInterface();
ArrayList<String> numbers = con.getPhoneContactNumbers(ContactsActivity.this);
for (int i=0; i<numbers.size();i++){
jobject.put(numbers.get(i));
}
ArrayList<NameValuePair> args = new ArrayList<NameValuePair>();
args.add(new BasicNameValuePair("numeri",jobject.toString()));
jobject = server.sendJsonArray("http://www.lemonsim.com/mobile/numeri_lemonsim.php", args);
return true;
}
@Override
protected void onPostExecute(Boolean success){
lemonSims = AppUtils.jsonArrayToListBoolean(jobject);
lemon_result = lemonSims;
AppUtils.saveBooleanArraySharedPreferences(ContactsActivity.LEMON_SHARED_PREF, lemonSims, ContactsActivity.this);
ContactsActivity.this.setContents(source);
diag.hide();
}
}
/**
* START CHAT
* @param numbers
* @param position
* @param n_pos
*/
protected void startChat(String[] numbers,int position, int n_pos){
Intent intent = new Intent(this, SmsChat.class);
intent.putExtra(SmsChat.MY_PHONE, my_number);
intent.putExtra(SmsChat.NUMBER, numbers[n_pos]);
intent.putExtra(SmsChat.NAME, names_result.get(position));
intent.putExtra(SmsChat.IS_LEMONSIM, lemon_result.get(position));
startActivity(intent);
}
class PopUpClickListener implements DialogInterface.OnClickListener{
@Override
public void onClick(DialogInterface dialog, int which) {
startChat(numbers, ContactsActivity.this.popup_pos, which);
}
}
@Override
public void onClick(DialogInterface dialog, int which) {
startChat(numbers, ContactsActivity.this.popup_pos, which);
}
}
最佳答案
您必须对点击监听器进行一些更改:
listview.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> l, View v, final int position,
long id) {
ContactsInterface con = new ContactsInterface();
numbers = con.getContactNumberByDisplayName(names_result.get(position), ContactsActivity.this);
popup_pos = position;
AlertDialog.Builder builder = new AlertDialog.Builder(
getApplicationContext());
if (numbers.length >1)
{
builder.setTitle(R.string.phone_numbers);
builder.setItems(numbers , new PopUpClickListener());
AlertDialog dialog = builder.create();
dialog.show();
}else{
startChat(numbers,position, 0);
}
}
});
关于android - 无法在 Android 上显示 AlertDialog，因为我收到 NullPointerException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19546814/