为什么我得到一个CursorIndexOutOfBoundsException？

我不认为我知道我的Cursor很好我几乎可以肯定我的代码也许是错误的，所以我打算将我的整个代码为什么我得到一个CursorIndexOutOfBoundsException？

package com.tanukiproductions.battleforchristmas; 

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 

public class SQLiteTable { 

public static final String KEY_ROWID = "_id"; 
public static final String KEY_LEVEL = "level"; 
public static final String KEY_HEALTH = "health"; 
public static final String KEY_NAME = "name"; 
public static final String KEY_CRIT = "crit"; 
public static final String KEY_CRIT_RANGE = "crit_range"; 
public static final String KEY_CRIT_INC = "crit_increment"; 
public static final String KEY_HIT_RANGE = "hit_range"; 
public static final String KEY_HIT_INC = "hit_increment"; 
public static final String KEY_CHAR_IMG = "character_image"; 
public static final String KEY_TOTAL_XP = "total_xp"; 
public static final String KEY_XP = "xp"; 
public static final String KEY_XP_NEEDED = "xp_needed"; 
public static final String KEY_COINS = "coins"; 
public static final String KEY_SMALL_POTS = "small_pots"; 
public static final String KEY_LARGE_POTS = "large_pots"; 

private static DbHelper ourHelper; 
private final Context ourContext; 
private static SQLiteDatabase ourDatabase; 

private static final String DB_NAME = "battle_for_christams"; 
private static final String DB_TBL = "stats"; 
private static final int DATABASE_VERSION = 1; 

private static class DbHelper extends SQLiteOpenHelper{ 

    public DbHelper(Context context) { 
     super(context, DB_NAME, null, DATABASE_VERSION); 
     // TODO Auto-generated constructor stub 
    } 
    @Override 
    public void onCreate(SQLiteDatabase db) { 
     // TODO Auto-generated method stub 
     db.execSQL("CREATE TABLE " + DB_TBL + " (" + 
       KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
       KEY_LEVEL + " INTEGER NOT NULL, " + 
       KEY_HEALTH + " INTEGER NOT NULL, " + 
       KEY_NAME + " TEXT NOT NULL, " + 
       KEY_CRIT + " INTEGER NOT NULL, " + 
       KEY_CRIT_RANGE + " INTEGER NOT NULL, " + 
       KEY_CRIT_INC + " INTEGER NOT NULL, " + 
       KEY_HIT_RANGE + " INTEGER NOT NULL, " + 
       KEY_HIT_INC + " INTEGER NOT NULL, " + 
       KEY_CHAR_IMG + " INTEGER NOT NULL, " + 
       KEY_TOTAL_XP + " INTEGER NOT NULL, " + 
       KEY_XP + " INTEGER NOT NULL, " + 
       KEY_XP_NEEDED + " INTEGER NOT NULL, " + 
       KEY_COINS + " INTEGER NOT NULL, " + 
       KEY_SMALL_POTS + " INTEGER NOT NULL, " + 
       KEY_LARGE_POTS + " INTEGER NOT NULL)" 
      ); 

     ContentValues values = new ContentValues(); 
     values.put(KEY_NAME, "User1"); 
     values.put(KEY_LEVEL, 1); 
     values.put(KEY_HEALTH, 10); 
     values.put(KEY_CRIT, 5); 
     values.put(KEY_CRIT_RANGE, 2); 
     values.put(KEY_CRIT_INC, 2); 
     values.put(KEY_HIT_RANGE, 2); 
     values.put(KEY_HIT_INC, 0); 
     values.put(KEY_TOTAL_XP, 0); 
     values.put(KEY_XP, 0); 
     values.put(KEY_XP_NEEDED, 5); 
     values.put(KEY_COINS, 5); 
     values.put(KEY_SMALL_POTS, 0); 
     values.put(KEY_LARGE_POTS, 0); 
     values.put(KEY_CHAR_IMG, 1); 
     db.insert(DB_TBL, null, values); 

    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // TODO Auto-generated method stub 
     db.execSQL("DROP TABLE IF EXIST " + DB_TBL); 
     onCreate(db); 
    } 

} 

public SQLiteTable(Context c){ 
    ourContext = c; 
    ourHelper = new DbHelper(ourContext); 
} 

public static void open() throws SQLException{ 
    ourDatabase = ourHelper.getWritableDatabase(); 
} 

public static void close() throws SQLException{ 
    ourHelper.close(); 
} 

public int getLevel() { 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_LEVEL}, null, null, null, null, null); 
    int level = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return level; 
} 

public int getHealth() { 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_HEALTH}, null, null, null, null, null); 
    int health = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return health; 
} 

public int getCrit() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_CRIT}, null, null, null, null, null); 
    int crit = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return crit; 
} 

public int getCritRange() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_CRIT_RANGE}, null, null, null, null, null); 
    int critRange = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return critRange; 
} 

public int getCritInc() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_CRIT_INC}, null, null, null, null, null); 
    int critInc = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return critInc; 
} 

public int getHitInc() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_HIT_INC}, null, null, null, null, null); 
    int hitInc = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return hitInc; 
} 

public int getHitRange() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_HIT_RANGE}, null, null, null, null, null); 
    int hitRange = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return hitRange; 
} 

public int getXp() { 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_XP}, null, null, null, null, null); 
    int xp = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return xp; 
} 

public void setXp(int xp){ 
    open(); 
    ContentValues values = new ContentValues(); 
    int xpNeeded = getXpNeeded(); 
    int XP = getXp() + xp; 
    int totalXp = getTotalXp() + xp; 
    if (XP >= xpNeeded){ 
     XP = XP - xpNeeded; 
     levelUp(); 
    } 
    values.put(KEY_XP, XP); 
    values.put(KEY_TOTAL_XP, totalXp); 
    ourDatabase.update(DB_TBL, values, null, null); 
    close(); 

} 

public int getXpNeeded() { 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_XP_NEEDED}, null, null, null, null, null); 
    int xpNeeded = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return xpNeeded; 
} 

public int getTotalXp() { 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_TOTAL_XP}, null, null, null, null, null); 
    int totalXp = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return totalXp; 
} 

public int getCoins() { 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_COINS}, null, null, null, null, null); 
    int coins = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return coins; 
} 

public String getName() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_NAME}, null, null, null, null, null); 
    String name = cursor.getString(0); 
    cursor.close(); 
    close(); 
    return name; 
} 

public void levelUp() { 
    // TODO Auto-generated method stub 
    ContentValues values = new ContentValues(); 
    int level = getLevel() + 1; 
    int health = getHealth() + 5; 
    double crit = getCrit() + 0.1; 
    int xpNeeded = getXpNeeded() + 5; 
    int critInc = getCritInc() + 1; 
    int hitInc; 
    int hitRange; 
    int critRange; 
    values.put(KEY_LEVEL, level); 
    values.put(KEY_HEALTH, health); 
    values.put(KEY_CRIT, crit); 
    values.put(KEY_XP_NEEDED, xpNeeded); 
    values.put(KEY_CRIT_INC, critInc); 
    if(level % 2 == 0){ 
     hitInc = getHitInc() + 1; 
     values.put(KEY_HIT_INC, hitInc); 
    } 
    if(level % 4 == 0){ 
     hitRange = getHitRange() + 1; 
     critRange = getCritRange() + 1; 
     values.put(KEY_HIT_RANGE, hitRange); 
     values.put(KEY_CRIT_RANGE, critRange); 
    } 
    ourDatabase.update(DB_TBL, values, null, null); 
} 

private int getLargePots() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_LARGE_POTS}, null, null, null, null, null); 
    int largePots = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return largePots; 
} 

private int getSmallPots() { 
    // TODO Auto-generated method stub 
    open(); 
    Cursor cursor = ourDatabase.query(DB_TBL, new String[] {KEY_SMALL_POTS}, null, null, null, null, null); 
    int smallPots = cursor.getInt(0); 
    cursor.close(); 
    close(); 
    return smallPots; 
} 

public void updateSmallPots() { 
    // TODO Auto-generated method stub 
    ContentValues values = new ContentValues(); 
    open(); 
    int smallPots = getSmallPots() + 1; 
    int coins = getCoins() - 1; 
    values.put(KEY_SMALL_POTS, smallPots); 
    values.put(KEY_COINS, coins); 
    ourDatabase.update(DB_TBL, values, null, null); 
    close(); 
} 

public void updateLargePots(){ 
    ContentValues values = new ContentValues(); 
    open(); 
    int largePots = getLargePots() + 1; 
    int coins = getCoins() - 2; 
    values.put(KEY_LARGE_POTS, largePots); 
    values.put(KEY_COINS, coins); 
    ourDatabase.update(DB_TBL, values, null, null); 
    close(); 
} 
}

这是我的logcat

01-04 16:12:25.596: E/AndroidRuntime(29517): android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1 
01-04 16:12:25.596: E/AndroidRuntime(29517): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580) 
01-04 16:12:25.596: E/AndroidRuntime(29517): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)

来源

2013-01-04 John

yea theres like 40 more。我想你不会希望他们所有人都大声笑。 – John

android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1

你忘了打电话给cursor.moveToFirst()，但你也应该确认光标不是空的，：

// Returns false if the Cursor cannot move to this position, i.e. empty 
if(cursor.moveToFirst()) { 
    // Read data from the first row 
}

来源

2013-01-04 22:24:29 Sam

另外，通常，while（cursor.moveToNext（））{...}。 – dokkaebi

事实上，如果你对多行感兴趣。 – Sam

山姆，你是这个网站上的天才新宠儿，即使你已经看到我所有的菜鸟问题。 – John

while循环或do-while循环遍历游标时的其他个人喜好是for循环。

for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) { 
} 
cursor.close();

来源

2013-02-26 18:30:02 UnflavoredMeson

为什么我得到一个CursorIndexOutOfBoundsException？

回答

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