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我正在開發一個應用程序。當我修改我的數據時，將顯示先前的數據，而不是更新的數據。這是ModifyActivity.java文件：SQLite數據庫沒有在應用程序內更新
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class ModifyCountryActivity extends Activity implements OnClickListener {
private EditText titleText, dateText, timeText;
private Button updateBtn, deleteBtn;
public Calendars calendars;
private DatabaseHelper dbHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("Modify Record");
setContentView(R.layout.activity_modify_record);
dbHelper = new DatabaseHelper(this);
calendars = new Calendars();
titleText = (EditText) findViewById(R.id.title_edittext_modify);
timeText = (EditText) findViewById(R.id.time_edittext_modify);
dateText = (EditText) findViewById(R.id.date_edittext_modify);
updateBtn = (Button) findViewById(R.id.btn_update);
deleteBtn = (Button) findViewById(R.id.btn_delete);
Intent intent = getIntent();
String title = intent.getStringExtra("title");
String time = intent.getStringExtra("time");
String date = intent.getStringExtra("date");
titleText.setText(title);
timeText.setText(time);
dateText.setText(date);
updateBtn.setOnClickListener(this);
deleteBtn.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btn_update:
titleText.setText(titleText.getText().toString() + " ");
timeText.setText(dateText.getText().toString() + " ");
dateText.setText(timeText.getText().toString() + " ");
calendars.set_remindertitle(titleText.getText().toString() + " ");
calendars.set_reminderdate(dateText.getText().toString() + " ");
calendars.set_remindertime(timeText.getText().toString() + " ");
dbHelper.update(calendars);
this.returnHome();
break;
case R.id.btn_delete:
dbHelper.delete(calendars);
this.returnHome();
break;
}
}
public void returnHome() {
Intent home_intent = new Intent(getApplicationContext(), CountryListActivity.class)
.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(home_intent);
}
}
數據庫不更新。它再次顯示以前的數據。這是數據庫類：
public class DatabaseHelper extends SQLiteOpenHelper {
public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "calendar.db";
public static final String TABLE_REMINDER = "reminder";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_REMINDER_TITLE = "_remindertitle";
public static final String COLUMN_REMINDER_DESCRIPTION = "_reminderdescription";
public static final String COLUMN_REMINDER_DATE = "_reminderdate";
public static final String COLUMN_REMINDER_TIME = "_remindertime";
public static final String COLUMN_REMINDER_REPEAT = "_reminderrepeat";
public static final String COLUMN_REMINDER_SNOOZE = "_remindersnooze";
SQLiteDatabase database;
// Database Information
Class<? extends DatabaseHelper> context = getClass();
DatabaseHelper dbHelper;
// Creating table query
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " + TABLE_REMINDER + " (" +
COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
COLUMN_REMINDER_DATE + " TEXT, " + COLUMN_REMINDER_TIME + " TEXT, " + COLUMN_REMINDER_TITLE + " TEXT, "
+ COLUMN_REMINDER_DESCRIPTION + " TEXT, " + COLUMN_REMINDER_REPEAT + " TEXT, " + COLUMN_REMINDER_SNOOZE + " TEXT " + ");";
Log.i("Query", query);
db.execSQL(query);
}
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_REMINDER);
onCreate(db);
}
public ArrayList<Calendars> databaseToArrayList() {
ArrayList<Calendars> arrayList = new ArrayList();
SQLiteDatabase db = getWritableDatabase();
String query = "SELECT * FROM " + TABLE_REMINDER;
Cursor c = db.rawQuery(query, null);
c.moveToFirst();
while (!c.isAfterLast()) {
if (c.getString(c.getColumnIndex("_reminderdate")) != null) {
Calendars calendars = new Calendars();
calendars.set_reminderdate(c.getString(c.getColumnIndex(COLUMN_REMINDER_DATE)));
calendars.set_remindertime(c.getString(c.getColumnIndex(COLUMN_REMINDER_TIME)));
calendars.set_remindertitle(c.getString(c.getColumnIndex(COLUMN_REMINDER_TITLE)));
calendars.set_reminderdescription(c.getString(c.getColumnIndex(COLUMN_REMINDER_DESCRIPTION)));
calendars.set_reminderrepeat(c.getString(c.getColumnIndex(COLUMN_REMINDER_REPEAT)));
calendars.set_remindersnooze(c.getString(c.getColumnIndex(COLUMN_REMINDER_SNOOZE)));
arrayList.add(calendars);
}
c.moveToNext();
}
c.close();
db.close();
return arrayList;
}
public void remove(String id) {
String string = String.valueOf(id);
SQLiteDatabase database = getReadableDatabase();
database.execSQL("DELETE FROM " + TABLE_REMINDER + " WHERE _id = '" + string + "'");
}
public void addReminder(Calendars calendars) {
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_REMINDER_DATE, calendars.get_reminderdate());
contentValues.put(COLUMN_REMINDER_TIME, calendars.get_remindertime());
contentValues.put(COLUMN_REMINDER_TITLE, calendars.get_remindertitle());
contentValues.put(COLUMN_REMINDER_DESCRIPTION, calendars.get_reminderdescription());
contentValues.put(COLUMN_REMINDER_REPEAT, calendars.get_reminderrepeat());
contentValues.put(COLUMN_REMINDER_SNOOZE, calendars.get_remindersnooze());
SQLiteDatabase database = getReadableDatabase();
database.insert(TABLE_REMINDER, null, contentValues);
Log.i("insData", "the data has been inseted");
database.close();
}
public Cursor fetch() {
String[] columns = new String[]{COLUMN_ID, /*COLUMN_REMINDER_DATE, COLUMN_REMINDER_TIME, COLUMN_REMINDER_TITLE,*/
COLUMN_REMINDER_DESCRIPTION, COLUMN_REMINDER_REPEAT, COLUMN_REMINDER_SNOOZE};
SQLiteDatabase database = getReadableDatabase();
Cursor cursor = database.query(TABLE_REMINDER, columns, null, null, null, null, null);
if (cursor != null)
{
cursor.moveToFirst();
}
return cursor;
}
public int update(Calendars calendars) {
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_REMINDER_DATE, calendars.get_reminderdate());
contentValues.put(COLUMN_REMINDER_TIME, calendars.get_remindertime());
contentValues.put(COLUMN_REMINDER_TITLE, calendars.get_remindertitle());/*
contentValues.put(COLUMN_REMINDER_DESCRIPTION, calendars.get_reminderdescription());
contentValues.put(COLUMN_REMINDER_REPEAT, calendars.get_reminderrepeat());
contentValues.put(COLUMN_REMINDER_SNOOZE, calendars.get_remindersnooze());*/
SQLiteDatabase database = getReadableDatabase();
int i = database.update(TABLE_REMINDER, contentValues, COLUMN_ID + " = " + calendars.get_id(), null);
database.close();
return i;
}
public void delete(Calendars calendars) {
database = getReadableDatabase();
database.delete(TABLE_REMINDER, COLUMN_ID + "=" + calendars.get_id(), null);
}
}
我相信更新按鈕應該工作正常。我是Android新手，不知道如何解決這個問題。有關如何解決它的任何建議？