Mobile versionHinweis: Der Fehler tritt auf, wenn ich auf den Listenansichtseintrag klicke, um auf eine Bearbeitungsseite für den Tagebucheintrag zuzugreifen. Es scheint jedoch überhaupt nicht zur Bearbeitungsseite zu gelangen.
Unten finden Sie meinen Aktivitätscode, auf dem es auftritt, und den Stacktrace.
Aktivitätscode:
Code: Select all
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.content.Intent;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
public class ViewDiaryEntries extends AppCompatActivity {
// Database Helper
MyDBHandler db;
// Listview
ListView data_list;
// Test var
public final static String KEY_EXTRA_DATA_ID = "KEY_EXTRA_DATA_ID";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_diary_entries);
db = new MyDBHandler(this);
// Displays the database items.
displayItems();
}
// To display items in the listview.
public void displayItems(){
// To display items in a listview.
ArrayList db_data_list = db.getDiaryDBDataList();
ArrayAdapter listAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, db_data_list);
// Set the adapter for the listview
data_list = (ListView) findViewById(R.id.dataListView);
data_list.setAdapter(listAdapter);
/* Experiment -------------------------------------------------------------*/
data_list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
// Selected item store
String selectedEntry = ((TextView) view).getText().toString();
// Test for regular expression
String[] listViewItemSplit = selectedEntry.split(" - ");
String listViewItempt1 = listViewItemSplit[0]; // For date and time
//String listViewItempt2 = listViewItemSplit[1]; // For save file name
//Toast.makeText(ViewDiaryEntries.this, listViewItempt1, Toast.LENGTH_LONG).show();
if(listViewItempt1.equals("")){
Toast.makeText(ViewDiaryEntries.this, "Error. Unable to detect entry ID.", Toast.LENGTH_LONG).show();
}
else{
// Pass on the data:
Intent editEntry = new Intent(ViewDiaryEntries.this, editdiaryentry.class);
editEntry.putExtra(KEY_EXTRA_DATA_ID, listViewItempt1);
startActivity(editEntry);
}
}
});
}
// For the go back button.
public void viewdiarytoinitialdiary_backbutt(View v){
// Create and start new intent going back ot main page.
Intent main_page = new Intent(ViewDiaryEntries.this, User_Main_Menu_Options.class);
main_page.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(main_page);
}
// For the about button.
public void viewdiarypage_directionabout_butt(View v){
// Create an alert dialog
final AlertDialog.Builder about_page_dialog = new AlertDialog.Builder(ViewDiaryEntries.this);
about_page_dialog.setTitle("About This Page:");
// Inputs values for the dialog message.
final String dialog_message = "This page will show you any saved diary entries you've.\n\n To edit an entry, do the following: \n\n- Take note of the Entry ID# (first value on entry display) \n- Type it in the number box at the bottom. \n- Press Edit Record icon next to number box, and wait for it to load.";
about_page_dialog.setMessage(dialog_message);
about_page_dialog.setPositiveButton("Got it!", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Closes the dialog.
dialog.cancel();
}
});
// Shows the dialog.
about_page_dialog.show();
}
// Main menu button.
public void viewDiaryEntriesMainMenushortcut_butt(View v){
// Creates main menu alert dialog.
AlertDialog.Builder mainMenu_Dialog = new AlertDialog.Builder(this);
mainMenu_Dialog.setIcon(R.drawable.main_menu_symbol);
mainMenu_Dialog.setTitle("Main Menu");
// Creates array adapter with items to fill the menu with.
final ArrayAdapter menuItemsAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1);
menuItemsAdapter.add("Home Screen");
menuItemsAdapter.add("Diary");
menuItemsAdapter.add("Tests");
menuItemsAdapter.add("Activity");
menuItemsAdapter.add("Media");
menuItemsAdapter.add("Thought of the Day");
menuItemsAdapter.add("Inspirational Quotes");
menuItemsAdapter.add("Resources");
menuItemsAdapter.add("Settings");
// To close menu.
mainMenu_Dialog.setPositiveButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// To go to appropriate page upon selection.
mainMenu_Dialog.setAdapter(menuItemsAdapter, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
String selectedItem = menuItemsAdapter.getItem(which);
if(selectedItem.equals("Home Screen")){
// Goes to main menu.
Intent mainMenu = new Intent(ViewDiaryEntries.this, User_Main_Menu_Options.class);
mainMenu.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(mainMenu);
}
else if(selectedItem.equals("Diary")){
// Goes to diary page.
Intent diaryPage = new Intent(ViewDiaryEntries.this, ViewDiaryEntries.class);
diaryPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(diaryPage);
}
else if(selectedItem.equals("Tests")){
// Goes to tests page.
Intent testsPage = new Intent(ViewDiaryEntries.this, TestChoices.class);
testsPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(testsPage);
}
else if(selectedItem.equals("Media")){
// Goes to media page.
Intent mediaPage = new Intent(ViewDiaryEntries.this, initialMediaPage.class);
mediaPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(mediaPage);
}
else if(selectedItem.equals("Thought of the Day")){
// Goes to thought of the day page.
Intent thoughtofthedayPage = new Intent(ViewDiaryEntries.this, thoughtQuotes.class);
thoughtofthedayPage.putExtra("quote_or_thought", 2);
thoughtofthedayPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(thoughtofthedayPage);
}
else if(selectedItem.equals("Inspirational Quotes")){
// Goes to inspirational quotes page.
Intent inspirationalquotesPage = new Intent(ViewDiaryEntries.this, thoughtQuotes.class);
inspirationalquotesPage.putExtra("quote_or_thought", 1);
inspirationalquotesPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(inspirationalquotesPage);
}
else if(selectedItem.equals("Settings")){
// Goes to settings page.
Intent settingsPage = new Intent(ViewDiaryEntries.this, settings.class);
settingsPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(settingsPage);
}
}
});
mainMenu_Dialog.show();
}
// For the settings button.
public void viewdiarypagelisttoSettings_butt(View v){
// Goes to settings page.
Intent settingsPage = new Intent(ViewDiaryEntries.this, settings.class);
settingsPage.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(settingsPage);
}
// For new entry.
public void viewdiarypageaddEntry_butt(View v){
// Opening up the diary add intent.
Intent newdiaryEntry = new Intent(ViewDiaryEntries.this, newdiaryentry.class);
startActivity(newdiaryEntry);
}
}
Code: Select all
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference
at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:401)
at android.widget.ArrayAdapter.getView(ArrayAdapter.java:369)
at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:194)
at android.widget.Spinner.onMeasure(Spinner.java:580)
at android.support.v7.widget.AppCompatSpinner.onMeasure(AppCompatSpinner.java:407)
at android.view.View.measure(View.java:18794)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
at android.view.View.measure(View.java:18794)
at android.widget.ScrollView.measureChildWithMargins(ScrollView.java:1283)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.widget.ScrollView.onMeasure(ScrollView.java:340)
at android.view.View.measure(View.java:18794)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
at android.view.View.measure(View.java:18794)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
at android.view.View.measure(View.java:18794)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at android.view.View.measure(View.java:18794)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
at android.view.View.measure(View.java:18794)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2643)
at android.view.View.measure(View.java:18794)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2100)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1216)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1452)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:606)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
BEARBEITEN:
Nachdem ich also zwischen der Datenbank und der Aktivität, mit der sie interagiert, zwischen dem Code und der Aktivität, mit der sie interagiert, hin und her gestarrt habe, ist es mir gelungen, sie wieder zum Laufen zu bringen. Unten ist, was ich in der genauen Reihenfolge getan habe:
- Ich habe festgestellt, dass ich ein Datumsfeld hatte, das keine Daten empfing, und habe das korrigiert.
- Das Projekt bereinigt.
- Android Studio neu gestartet (im Wesentlichen alle Vorgänge der Entwicklungsumgebung angehalten).
- Die App von meinem Entwicklertelefon deinstalliert.
- Android Studio neu gestartet und Habe die App neu installiert.
- Irgendwie funktioniert es =_=, ja, es ist magisch.
