【发布时间】：2016-05-02 06:43:21
【问题描述】：
我使用微调器从数据库中获取所有学校名称。以及用于过滤学校名称的文本框。它适用于除 android 6.o 之外的所有 android 版本。 当我在 android 6.0 中运行程序时，出现以下错误：
错误：
java.lang.RuntimeException：无法启动活动 ComponentInfo{pencilrulernidhinkumar.pencilruler/pencilrulernidhinkumar.pencilruler.PupilRegi}：java.lang.NullPointerException：尝试调用虚拟方法 'android.widget.Filter android.widget.ArrayAdapter.getFilter ()' 在空对象引用上 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426) 在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) 在 android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4098) 在 android.app.ActivityThread.-wrap15(ActivityThread.java) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1360) 在 android.os.Handler.dispatchMessage(Handler.java:102) 在 android.os.Looper.loop(Looper.java:148) 在 android.app.ActivityThread.main(ActivityThread.java:5443) 在 java.lang.reflect.Method.invoke（本机方法） 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
原因：java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法 'android.widget.Filter android.widget.ArrayAdapter.getFilter()' 在pencilrulernidhinkumar.pencilruler.PupilRegi$5.onTextChanged（PupilRegi.java:189） 在 android.widget.TextView.sendOnTextChanged(TextView.java:7998) 在 android.widget.TextView.setText(TextView.java:4355) 在 android.widget.TextView.setText(TextView.java:4209) 在 android.widget.EditText.setText(EditText.java:84) 在 android.widget.TextView.setText(TextView.java:4184) 在 android.widget.TextView.onRestoreInstanceState(TextView.java:4077) 在 android.view.View.dispatchRestoreInstanceState(View.java:14768) 在 android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3129) 在 android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3129) 在 android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3129) 在 android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3129) 在 android.view.View.restoreHierarchyState(View.java:14746) 在 com.android.internal.policy.PhoneWindow.restoreHierarchyState(PhoneWindow.java:2035) 在 android.app.Activity.onRestoreInstanceState(Activity.java:1012) 在 android.app.Activity.performRestoreInstanceState(Activity.java:967) 在 android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1186) 在 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2399)
这是我的班级文件，用于加载学校名称并对其进行过滤。
public class PupilRegi extends Activity{
private static final String PREF_FIRSTLAUNCH_HELP = "helppupilregister";
private boolean helpDisplayed = false;
EditText pupilname,pupusername,puppassword,codezip,schoolsearch;
TextView pupdob,imagepath;
Spinner pupyear,pupschool;
Button submit;
ResultSet rs;
Boolean isInternetPresent = false;
ConnectionDetector cd;
AlertDialog alert;
ArrayAdapter<String> spinnerAdapter;
ConnectionClass connectionClass;
String orig,names,imagename,imgpath;
private int year;
private int month;
private int day;
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
public static final int MEDIA_TYPE_IMAGE = 1;
private Uri fileUri;
static final int DATE_PICKER_ID = 1111;
public static final String USER_NAME = "USER_NAME";
public static final String PASSWORD = "PASSWORD";
private static final String LOGIN_URL = "http://balajee2777-001-site1.1tempurl.com/backup-07032016/studentregister.php";
private String URL_CATEGORIES = "http://balajee2777-001-site1.1tempurl.com/backup-07032016/spinnerdb/get_categories.php";
private String URL_SCHOOL = "http://balajee2777-001-site1.1tempurl.com/backup-07032016/spinnerdb/school.php";
public static Bitmap bitmap;
private ArrayList<Category> categoriesList;
private ArrayList<Categories> categoriesSchool;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.student);
cd = new ConnectionDetector(getApplicationContext());
isInternetPresent = cd.isConnectingToInternet();
showHelpForFirstLaunch();
schoolsearch=(EditText)findViewById(R.id.inputSearch);
pupyear=(Spinner)findViewById(R.id.regpupilyear);
pupschool=(Spinner)findViewById(R.id.regschoolname);
pupilname=(EditText)findViewById(R.id.rdtextpupilname);
pupdob=(TextView)findViewById(R.id.regeddob);
imagepath=(TextView)findViewById(R.id.reggtvimagepath);
pupusername=(EditText)findViewById(R.id.regedusername);
puppassword=(EditText)findViewById(R.id.regedpassword);
codezip=(EditText)findViewById(R.id.edzipcode);
submit=(Button)findViewById(R.id.btnsubmitreg);
connectionClass= new ConnectionClass();
final Calendar c = Calendar.getInstance();
year = c.get(Calendar.YEAR);
month = c.get(Calendar.MONTH);
day = c.get(Calendar.DAY_OF_MONTH);
categoriesList = new ArrayList<Category>();
categoriesSchool=new ArrayList<Categories>();
pupdob.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showDialog(DATE_PICKER_ID);
}
});
if(isInternetPresent){
new Getyear().execute();
new Getschool().execute();
}else{
neti();
}
submit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(isInternetPresent) {
login();
}else{
neti();
}
}
});
schools();
}
private void showHelpForFirstLaunch() {
helpDisplayed = getPreferenceValue(PREF_FIRSTLAUNCH_HELP, false);
if (!helpDisplayed) {
showHelp();
savePreference(PREF_FIRSTLAUNCH_HELP, true);
}else if(helpDisplayed){
return;
}
}
private void showHelp() {
final View instructionsContainer = findViewById(R.id.container_help);
instructionsContainer.setVisibility(View.VISIBLE);
instructionsContainer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
instructionsContainer.setVisibility(View.INVISIBLE);
}
});
}
private boolean getPreferenceValue(String key, boolean defaultValue) {
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
return preferences.getBoolean(key, defaultValue);
}
private void savePreference(String key, boolean value) {
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putBoolean(key, value);
editor.commit();
}
private void neti() {
final LayoutInflater layoutInflater = LayoutInflater.from(PupilRegi.this);
final View promptView = layoutInflater.inflate(R.layout.connectionlost, null);
final AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(PupilRegi.this);
alertDialogBuilder.setView(promptView);
alertDialogBuilder.setCancelable(false);
final Button retry=(Button)promptView.findViewById(R.id.btnretry);
retry.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent=getIntent();
finish();
startActivity(intent);
}
});
alert= alertDialogBuilder.create();
alert.show();
}
private void schools() {
schoolsearch.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
PupilRegi.this.spinnerAdapter.getFilter().filter(s);
}
@Override
public void afterTextChanged(Editable s) {
}
});
}
private void login() {
String imgepath=codezip.getText().toString();
String name=pupilname.getText().toString();
String dob=pupdob.getText().toString();
String school=pupschool.getSelectedItem().toString();
String year=pupyear.getSelectedItem().toString();
String username = pupusername.getText().toString();
String password = puppassword.getText().toString();
if(name.isEmpty() && username.isEmpty() && imgepath.isEmpty() && password.isEmpty()){
Toast.makeText(PupilRegi.this, "Enter all fields", Toast.LENGTH_LONG).show();
}else if(name.isEmpty()) {
Toast.makeText(PupilRegi.this, "Enter Yourname", Toast.LENGTH_LONG).show();
}else if(username.isEmpty()){
Toast.makeText(PupilRegi.this,"Enter username",Toast.LENGTH_LONG).show();
}else if(password.isEmpty()) {
Toast.makeText(PupilRegi.this, "Enter password", Toast.LENGTH_LONG).show();
}else if(imgepath.isEmpty()) {
Toast.makeText(PupilRegi.this, "Enter ZipCode", Toast.LENGTH_LONG).show();
}else {
userLogin(name,dob,school,year,imgepath,username, password);
}
}
private void userLogin(String name,String dob,String school,String year,String imgepath, final String username, final String password) {
class UserLoginClass extends AsyncTask<String,Void,String> {
ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(PupilRegi.this, "Wait a while!", null, true, true);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
// pb1.setVisibility(View.INVISIBLE
Intent intent = new Intent(PupilRegi.this, SqlLogin.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
// intent.putExtra(USER_NAME, username);
startActivity(intent);
finish();
}
@Override
protected String doInBackground(String... params) {
HashMap<String,String> data = new HashMap<>();
data.put("name",params[0]);
data.put("dob",params[1]);
data.put("school",params[2]);
data.put("year",params[3]);
data.put("imgepath",params[4]);
data.put("username",params[5]);
data.put("password",params[6]);
RegisterUserClass ruc = new RegisterUserClass();
String result = ruc.sendPostRequest(LOGIN_URL,data);
return result;
}
}
UserLoginClass ulc = new UserLoginClass();
ulc.execute(name,dob,school,year,imgepath,username,password);
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DATE_PICKER_ID:
return new DatePickerDialog(this, pickerListener, year, month,day);
}
return null;
}
private DatePickerDialog.OnDateSetListener pickerListener = new DatePickerDialog.OnDateSetListener() {
// when dialog box is closed, below method will be called.
@Override
public void onDateSet(DatePicker view, int selectedYear,
int selectedMonth, int selectedDay) {
year = selectedYear;
month = selectedMonth;
day = selectedDay;
// Show selected date
pupdob.setText(new StringBuilder().append(day)
.append("-").append(month + 1).append("-").append(year)
.append(" "));
}
};
private class Getyear extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// pDialog = new ProgressDialog(MainActivity.this);
// pDialog.setMessage("Fetching food categories..");
// pDialog.setCancelable(false);
// pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
ServiceHandler jsonParser = new ServiceHandler();
String json = jsonParser.makeServiceCall(URL_CATEGORIES, ServiceHandler.GET);
Log.e("Response: ", "> " + json);
if (json != null) {
try {
JSONObject jsonObj = new JSONObject(json);
if (jsonObj != null) {
JSONArray categories = jsonObj
.getJSONArray("categories");
for (int i = 0; i < categories.length(); i++) {
JSONObject catObj = (JSONObject) categories.get(i);
Category cat = new Category(catObj.getString("Grade"));
categoriesList.add(cat);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("JSON Data", "Didn't receive any data from server!");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// if (pDialog.isShowing())
// pDialog.dismiss();
populateSpinner();
}
}
private void populateSpinner() {
List<String> lables = new ArrayList<String>();
//txtCategory.setText("");
for (int i = 0; i < categoriesList.size(); i++) {
lables.add(categoriesList.get(i).getName());
}
// Creating adapter for spinner
ArrayAdapter<String> spinnerAdapter= new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, lables){
public View getView(int position, View convertView, ViewGroup parent)
{
View v = super.getView(position, convertView, parent);
((TextView) v).setTypeface(SingleItem.sTypeFace(getApplicationContext()));//Typeface for normal view
return v;
}
public View getDropDownView(int position, View convertView, ViewGroup parent)
{
View v = super.getDropDownView(position, convertView, parent);
((TextView) v).setTypeface(SingleItem.sTypeFace(getApplicationContext()));//Typeface for dropdown view
((TextView)v).setTextColor(Color.parseColor("#FFFFFF"));
// ((TextView)v).setTypeface(null,Typeface.BOLD);
((TextView) v).setBackgroundColor(Color.parseColor("#c13d48"));
return v;
}
};
// Drop down layout style - list view with radio button
spinnerAdapter
.setDropDownViewResource(android.R.layout.simple_list_item_single_choice);
// attaching data adapter to spinner
pupyear.setAdapter(spinnerAdapter);
}
private class Getschool extends AsyncTask<Void, Void, Void>{
@Override
protected void onPreExecute() {
super.onPreExecute();
// pDialog = new ProgressDialog(MainActivity.this);
// pDialog.setMessage("Fetching food categories..");
// pDialog.setCancelable(false);
// pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
ServiceHandler jsonParser = new ServiceHandler();
String json = jsonParser.makeServiceCall(URL_SCHOOL, ServiceHandler.GET);
Log.e("Response: ", "> " + json);
if (json != null) {
try {
JSONObject jsonObj = new JSONObject(json);
if (jsonObj != null) {
JSONArray school = jsonObj
.getJSONArray("school");
for (int i = 0; i < school.length(); i++) {
JSONObject catObj = (JSONObject) school.get(i);
Categories catz = new Categories(catObj.getString("School_Name"));
categoriesSchool.add(catz);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("JSON Data", "Didn't receive any data from server!");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// if (pDialog.isShowing())
// pDialog.dismiss();
populateSchool();
}
}
private void populateSchool() {
List<String> labls = new ArrayList<String>();
//txtCategory.setText("");
for (int i = 0; i < categoriesSchool.size(); i++) {
labls.add(categoriesSchool.get(i).getName());
}
// Creating adapter for spinner
spinnerAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, labls){
public View getView(int position, View convertView, ViewGroup parent)
{
View v = super.getView(position, convertView, parent);
((TextView) v).setTypeface(SingleItem.sTypeFace(getApplicationContext()));//Typeface for normal view
return v;
}
public View getDropDownView(int position, View convertView, ViewGroup parent)
{
View v = super.getDropDownView(position, convertView, parent);
((TextView) v).setTypeface(SingleItem.sTypeFace(getApplicationContext()));//Typeface for dropdown view
((TextView)v).setTextColor(Color.parseColor("#FFFFFF"));
// ((TextView)v).setTypeface(null,Typeface.BOLD);
((TextView) v).setBackgroundColor(Color.parseColor("#c13d48"));
return v;
}
};
// Drop down layout style - list view with radio button
spinnerAdapter
.setDropDownViewResource(android.R.layout.simple_list_item_single_choice);
// attaching data adapter to spinner
pupschool.setAdapter(spinnerAdapter);
}
【问题讨论】：
标签： android filter textview android-spinner