Java 如何在数据库中正确添加图像和字符串?
我犯了这个错误 java.lang.IndexOutOfBoundsException:索引0无效,大小为0 这个错误可能是由于添加到数据库中导致的。java.lang.IndexOutOfBoundsException:索引0无效,大小为0 我是否正确地将位图转换为数据库 这可能导致阵列上出现错误: DbHelper.javaJava 如何在数据库中正确添加图像和字符串?,java,android,database,image,sqlite,Java,Android,Database,Image,Sqlite,我犯了这个错误 java.lang.IndexOutOfBoundsException:索引0无效,大小为0 这个错误可能是由于添加到数据库中导致的。java.lang.IndexOutOfBoundsException:索引0无效,大小为0 我是否正确地将位图转换为数据库 这可能导致阵列上出现错误: DbHelper.java package com.example.quizjavatest; import java.util.ArrayList; import java.util.List
package com.example.quizjavatest;
import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.BitmapFactory;
public class DbHelper extends SQLiteOpenHelper{
private Context mContext;
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "PediaKids";
// tasks table name
private static final String TABLE_QUEST = "planet";
// tasks Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_IMG = "img";
private static final String KEY_QUES = "question";
private static final String KEY_ANSWER = "answer"; //correct option
private static final String KEY_OPTA= "opta"; //option a
private static final String KEY_OPTB= "optb"; //option b
private static final String KEY_OPTC= "optc"; //option c
private SQLiteDatabase dbase;
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
dbase=db;
String Sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST + " ( "+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "+ KEY_IMG + " BLOB," + KEY_QUES
+ " TEXT, " + KEY_OPTA +" TEXT, " + KEY_OPTB +" TEXT, "+KEY_OPTC+" TEXT," + KEY_ANSWER + " TEXT)";
db.execSQL(Sql);
addQuestion();
//db.close();
}
private void addQuestion()
{
Question q1=new Question(BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ic_launcher),"an operating system?", "SuSe", "BIOS", "DOS", "BIOS");
this.addQuestion(q1);
Question q2=new Question(BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ic_launcher),"Which of the following is NOT "," SuSe", "BIOS", "DOS", "BIOS");
this.addQuestion(q2);
Question q3=new Question(BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ic_launcher),"Which of the following is the fastest","RAM", "FLASH","Register","Register");
this.addQuestion(q3);
Question q4=new Question(BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ic_launcher),"Which of the following device", "Router", "Bridge", "Hub","Router");
this.addQuestion(q4);
Question q5=new Question(BitmapFactory.decodeResource(mContext.getResources(), R.drawable.ic_launcher),"Which of the following is NOT an" ,"Ruby","Python","BASIC","BASIC");
this.addQuestion(q5);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUEST);
// Create tables again
onCreate(db);
}
// Adding new question
public void addQuestion(Question quest) {
//SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
//values.put(KEY_ID, quest.getID());
//values.put(KEY_IMG, Utility.getBytes(quest.getBitmap()));
values.put(KEY_QUES, quest.getQUESTION());
values.put(KEY_ANSWER, quest.getANSWER());
values.put(KEY_OPTA, quest.getOPTA());
values.put(KEY_OPTB, quest.getOPTB());
values.put(KEY_OPTC, quest.getOPTC());
// Inserting Row
dbase.insert(TABLE_QUEST, null, values);
}
public List<Question> getAllQuestions(){
List<Question> quesList = new ArrayList<Question>();
String selectQuery = "SELECT * FROM " + TABLE_QUEST + " ORDER BY RANDOM() LIMIT 5";
dbase=this.getReadableDatabase();
Cursor cursor = dbase.rawQuery(selectQuery, null);
// looping through all rows and adding to list
//==============================================
if (cursor.moveToFirst()) {
do {
Question quest = new Question();
quest.setID(cursor.getInt(0));
//quest.setImage(Utility.getPhoto(cursor.getBlob(1)));
quest.setQUESTION(cursor.getString(1));
quest.setANSWER(cursor.getString(2));
quest.setOPTA(cursor.getString(3));
quest.setOPTB(cursor.getString(4));
quest.setOPTC(cursor.getString(5));
quesList.add(quest);
} while (cursor.moveToNext());
}
// return quest list
return quesList;
}
//==============================================
public int rowcount()
{
int row=0;
String selectQuery = "SELECT * FROM " + TABLE_QUEST;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
row=cursor.getCount();
return row;
}
}
尝试重新安装应用程序。重新安装意味着,你必须完全卸载应用程序,然后重新安装应用程序
发生此错误的原因是,在开发应用程序时,如果在安装应用程序一次后进行了任何更改,从而改变了数据库的结构,则应用程序的旧版本无法找到更改
因此,重新安装应用程序会有所帮助。重新安装应用程序后再试一次……首先,您必须从设备上卸载应用程序。.它在哪一行抛出ArrayIndexOutOfBound错误?@Lal..LOL这是工作,伙计。谢谢需要3天来修复此错误。哦,太好了如果我加上一个,你能把我的答案标记为接受吗@拉尔,在那之前,你能解释一下这个错误吗?