我正在使用android中的一个表单，我通过选择另一个下拉列表的值来渲染一个下拉列表的值，该下拉列表位于当前下拉列表的顶部。
所以在这里，我从大学下拉列表中选择一所大学，然后选择我正在渲染机构的价值并将其添加到机构下拉列表中，然后我从机构下拉列表中选择一个机构。
直到这里一切都很好，但在那之后，如果我再次改变大学，那么应用程序正在崩溃。
问题是，在logcat中它显示NullPointerException，但它没有显示崩溃或导致崩溃的行号。
logcat的：
FATAL EXCEPTION: main
java.lang.NullPointerException
at android.widget.Spinner.makeAndAddView(Spinner.java:548)
at android.widget.Spinner.layout(Spinner.java:496)
at android.widget.Spinner.onLayout(Spinner.java:460)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1670)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1528)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1441)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.widget.ScrollView.onLayout(ScrollView.java:1470)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1670)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1528)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1441)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1670)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1528)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1441)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
at android.view.View.layout(View.java:14243)
at android.view.ViewGroup.layout(ViewGroup.java:4490)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2230)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1994)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1181)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4942)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:776)
at android.view.Choreographer.doCallbacks(Choreographer.java:579)
at android.view.Choreographer.doFrame(Choreographer.java:548)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:762)
at android.os.Handler.handleCallback(Handler.java:800)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5370)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
EducationalSchoolCollege.java
public class EducationalSchoolCollege extends AppCompatActivity {
private RadioGroup rg__educational_type;
private RadioButton radioeduButton;
Spinner university,instituition,degree,stream,tenureType,tenureLevel,cycleSpinner;
String student_uuid,student_name,email_id,selectedTypeIs="";
Map<String,String> educationSubmitMapData = new HashMap<>();
Map<String,String> universityListMap = new HashMap<>();
Map<String,String> instituteListMap = new HashMap<>();
List<String> universityList = new ArrayList<>();
List<String> instituteList = new ArrayList<>();
List<String> degreeList = new ArrayList<>();
List<String> streamList = new ArrayList<>();
List<String> tenureTypeList = new ArrayList<>();
List<String> tenureLevelList = new ArrayList<>();
List<String> cycleList = new ArrayList<>();
List<String> universityNameList = new ArrayList<>();
List<String> instituteNameList = new ArrayList<>();
List<String> degreeNameList = new ArrayList<>();
List<String> streamNameList = new ArrayList<>();
List<String> tenureNameList = new ArrayList<>();
List<String> tenureLevelNameList = new ArrayList<>();
List<String> cycleNameList = new ArrayList<>();
String university_uuid,institute_uuid,degree_uuid,stream_uuid,tenure_uuid,tenure_level_uuid,cycle_uuid,degree_name;
Button submitEducationalBtn;
SharedPreferences afterClassPref;
AfterClassApp controller;
public ProgressDialog progdialog;
TextView clickHereId;
String fromProfile = "",genreic_user="";
//avinash
// TextView textView4;
TextView degreeText,streamText,tenureText,cycleText;
EditText edt_instituition_other;
boolean selectedIsOther=false;
boolean isCheckedRadio = false;
//avinash
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.educational_school_college);
controller = (AfterClassApp) getApplicationContext();
afterClassPref = getApplicationContext().getSharedPreferences(Constants.SHARED_PREF_NAME, Context.MODE_PRIVATE);
student_uuid = afterClassPref.getString("studentUUID", null);
student_name = afterClassPref.getString("studentName", null);
email_id = afterClassPref.getString("studentEmail", null);
university = (Spinner) findViewById(R.id.university);
instituition = (Spinner) findViewById(R.id.instituition);
degree = (Spinner) findViewById(R.id.degree);
stream = (Spinner) findViewById(R.id.stream);
tenureType = (Spinner) findViewById(R.id.tenure);
tenureLevel = (Spinner) findViewById(R.id.tenureLevel);
cycleSpinner = (Spinner) findViewById(R.id.cycle);
submitEducationalBtn = (Button) findViewById(R.id.submitEducationalBtn);
clickHereId = (TextView) findViewById(R.id.clickHereId);
//avinash
edt_instituition_other = (EditText)findViewById(R.id.edt_instituition_other);
degreeText=(TextView)findViewById(R.id.degreeText);
streamText=(TextView)findViewById(R.id.streamText);
tenureText=(TextView)findViewById(R.id.tenureText);
cycleText=(TextView)findViewById(R.id.cycleText);
// textView4 = (TextView)findViewById(R.id.textView4);
rg__educational_type = (RadioGroup) findViewById(R.id.rg__educational_type);
clickHereId.setVisibility(View.GONE);
if (Build.VERSION.SDK_INT < 21) {
rg__educational_type.setPadding(3,3,3,3);
}
Bundle extras = getIntent().getExtras();
if (extras != null) {
if (extras.containsKey("from_profile")){
fromProfile = extras.getString("from_profile");
}
if (extras.containsKey("genreic_user")){
genreic_user = extras.getString("genreic_user");
}
}
//G Analytics
if (!Constants.IS_EMAIL_EXIT) {
Tracker tracker = ((AfterClassApp) getApplication()).getTracker(AfterClassApp.TrackerName.APP_TRACKER);
tracker.setScreenName("MyAfterClass EducationalSchoolCollege");
tracker.send(new HitBuilders.AppViewBuilder().build());
}
rg__educational_type.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener()
{
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
int selectedId = rg__educational_type.getCheckedRadioButtonId();
radioeduButton = (RadioButton) findViewById(selectedId);
instituition.setAdapter(null);
degree.setAdapter(null);
stream.setAdapter(null);
tenureType.setAdapter(null);
tenureLevel.setAdapter(null);
cycleSpinner.setAdapter(null);
if(radioeduButton.getText().toString().equals("School")){
edt_instituition_other.setVisibility(View.GONE);
isCheckedRadio = true;
clickHereId.setVisibility(View.GONE);
setAdapter(university,universityNameList);
universityList.clear();
instituteList.clear();
degreeList.clear();
streamList.clear();
tenureTypeList.clear();
tenureLevelList.clear();
cycleList.clear();
universityNameList.clear();
instituteNameList.clear();
degreeNameList.clear();
streamNameList.clear();
tenureNameList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
firstTimeSchoolUserData("university",null,null,null,null);
selectedTypeIs = "board";
degreeText.setVisibility(View.GONE);
degree.setVisibility(View.GONE);
stream.setVisibility(View.GONE);
tenureType.setVisibility(View.GONE);
cycleSpinner.setVisibility(View.GONE);
streamText.setVisibility(View.GONE);
tenureText.setVisibility(View.GONE);
cycleText.setVisibility(View.GONE);
}
if(radioeduButton.getText().toString().equals("College")){
edt_instituition_other.setVisibility(View.GONE);
isCheckedRadio = true;
if ("yes".equalsIgnoreCase(genreic_user)){
clickHereId.setVisibility(View.GONE);
}else{
clickHereId.setVisibility(View.VISIBLE);
}
setAdapter(university,universityNameList);
universityList.clear();
instituteList.clear();
degreeList.clear();
streamList.clear();
tenureTypeList.clear();
tenureLevelList.clear();
cycleList.clear();
universityNameList.clear();
instituteNameList.clear();
degreeNameList.clear();
streamNameList.clear();
tenureNameList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
firstTimeUserData("university", null, null,null,null,null,null,null);
selectedTypeIs = "college";
degreeText.setVisibility(View.VISIBLE);
degree.setVisibility(View.VISIBLE);
stream.setVisibility(View.VISIBLE);
tenureType.setVisibility(View.VISIBLE);
cycleSpinner.setVisibility(View.VISIBLE);
streamText.setVisibility(View.VISIBLE);
tenureText.setVisibility(View.VISIBLE);
cycleText.setVisibility(View.VISIBLE);
}
}
});
// avinash
clickHereId.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(EducationalSchoolCollege.this, OtherFirstTimeEducational.class);
startActivity(intent);
}
});
// setAdapter(university,universityList);
// firstTimeUserData("university",null,null,null,null,null,null,null);
university.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String seluniversity = (String) university.getSelectedItem();
instituteList.clear();;
degreeList.clear();
streamList.clear();
tenureTypeList.clear();
tenureLevelList.clear();
cycleList.clear();
instituteNameList.clear();;
degreeNameList.clear();
streamNameList.clear();
tenureNameList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
Log.d("UNI ","seluniversity "+ seluniversity+ " pos:: "+position);
// clear on proper selecting
// clear on proper selecting
if ("board".equalsIgnoreCase(selectedTypeIs)){
//Todo
university_uuid = universityListMap.get(seluniversity);
firstTimeSchoolUserData("institute",university_uuid,null,null,null);
}else{
if (!"Select".equalsIgnoreCase(seluniversity)){
university_uuid = universityList.get(position-1);
educationSubmitMapData.put("university_uuid",university_uuid);
Log.d("UNI ", "university_uuid "+university_uuid);
// firstTimeUserInstitutionData("institute",university_uuid);
firstTimeUserData("institute",university_uuid,null,null,null,null,null,null);
}else{
university_uuid = null;
}
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
instituition.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String selInstitute = (String) instituition.getSelectedItem();
degreeList.clear();
streamList.clear();
tenureTypeList.clear();
tenureLevelList.clear();
cycleList.clear();
degreeNameList.clear();
streamNameList.clear();
tenureNameList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
if ("board".equalsIgnoreCase(selectedTypeIs)) {
//Todo
institute_uuid = instituteListMap.get(selInstitute);
if ("other".equalsIgnoreCase(selInstitute)){
// TODO: Hide edittext box and show here
edt_instituition_other.setVisibility(View.VISIBLE);
selectedIsOther=true;
}else{
selectedIsOther=false;
edt_instituition_other.setVisibility(View.GONE);
}
tenureLevelList.clear();
firstTimeSchoolUserData("tenure_level", university_uuid, institute_uuid, null, null);
} else {
if (!"Select".equalsIgnoreCase(selInstitute)) {
// int position = university.getSelectedItemPosition();
if(instituteList.size()==0){
return;
}
edt_instituition_other.setVisibility(View.GONE);
institute_uuid = instituteList.get(position - 1);
educationSubmitMapData.put("institute_uuid", institute_uuid);
// firstTimeUserDegreeData("degree", university_uuid, institute_uuid);
firstTimeUserData("degree", university_uuid, institute_uuid, null, null, null, null, null);
} else {
institute_uuid = null;
}
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
degree.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String selInstitute = (String) degree.getSelectedItem();
streamList.clear();
tenureTypeList.clear();
tenureLevelList.clear();
cycleList.clear();
streamNameList.clear();
tenureNameList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
if (!"Select".equalsIgnoreCase(selInstitute)){
// int position = university.getSelectedItemPosition();
if(degreeList.size()==0){
return;
}
degree_uuid = degreeList.get(position-1);
degree_name = degreeNameList.get(position-1);
// Log.d("degree_name",""+degree_name);
educationSubmitMapData.put("degree_uuid",degree_uuid);
// firstTimeUserDegreeData("degree", university_uuid, institute_uuid);
firstTimeUserData("stream",university_uuid,institute_uuid,degree_uuid,null,null,null,null);
}else{
degree_uuid = null;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
stream.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String selInstitute = (String) stream.getSelectedItem();
tenureTypeList.clear();
tenureLevelList.clear();
cycleList.clear();
tenureNameList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
if (!"Select".equalsIgnoreCase(selInstitute)){
// int position = university.getSelectedItemPosition();
if(streamList.size()==0){
return;
}
stream_uuid = streamList.get(position-1);
educationSubmitMapData.put("stream_uuid",stream_uuid);
// firstTimeUserDegreeData("degree", university_uuid, institute_uuid);
firstTimeUserData("tenure_type",university_uuid,institute_uuid,degree_uuid,stream_uuid,null,null,null);
}else{
stream_uuid = null;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
tenureType.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String selInstitute = (String) tenureType.getSelectedItem();
tenureLevelList.clear();
cycleList.clear();
tenureLevelNameList.clear();
cycleNameList.clear();
if (!"Select".equalsIgnoreCase(selInstitute)){
// int position = university.getSelectedItemPosition();
if(tenureTypeList.size()==0){
return;
}
tenure_uuid = tenureTypeList.get(position-1);
educationSubmitMapData.put("tenure_type",tenure_uuid);
// firstTimeUserDegreeData("degree", university_uuid, institute_uuid);
firstTimeUserData("tenure_level",university_uuid,institute_uuid,degree_uuid,stream_uuid,tenure_uuid,null,null);
}else{
tenure_uuid = null;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
tenureLevel.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String selInstitute = (String) tenureLevel.getSelectedItem();
cycleList.clear();
cycleNameList.clear();
if (!"Select".equalsIgnoreCase(selInstitute)){
// int position = university.getSelectedItemPosition();
if(tenureLevelList.size()==0){
return;
}
tenure_level_uuid = tenureLevelList.get(position-1);
educationSubmitMapData.put("tenure_level",tenure_level_uuid);
// firstTimeUserDegreeData("degree", university_uuid, institute_uuid);
firstTimeUserData("cycle",university_uuid,institute_uuid,degree_uuid,stream_uuid,tenure_uuid,tenure_level_uuid,null);
}else{
tenure_level_uuid = null;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
cycleSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long arg3) {
String selInstitute = (String) cycleSpinner.getSelectedItem();
if (!"Select".equalsIgnoreCase(selInstitute)){
// int position = university.getSelectedItemPosition();
if(cycleList.size()==0){
return;
}
cycle_uuid = cycleList.get(position-1);
educationSubmitMapData.put("cycle",cycle_uuid);
// firstTimeUserDegreeData("degree", university_uuid, institute_uuid);
// firstTimeUserData("cycle",university_uuid,institute_uuid,degree_uuid,stream_uuid,tenure_uuid,cycle_uuid,null);
}else{
cycle_uuid = null;
}
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
}
答案 0 :(得分：1)
发生NullPointerException，因为您设置的适配器为null。在Spinner中删除setAdapter（null）。
instituition.setAdapter(null);
degree.setAdapter(null);
stream.setAdapter(null);
tenureType.setAdapter(null);
tenureLevel.setAdapter(null);
cycleSpinner.setAdapter(null);
答案 1 :(得分：1)
您不应该mySpinner.setEnabled(false)而不是这样，您可以使用{{1}}。虽然它不一样，但你必须妥协