SQLite ListView CursorIndexOutofBoundsException：请求索引-1，大小为0

时间：2013-05-19 21:24:54

标签： android android-listview android-sqlite

我成功地在SQLite数据库中设置了一对填充了纬度和经度对的ListView。我编写了代码，以便我可以点击其中一对来调用Google地图并从用户的当前位置导航到那里。当我点击时，我得到一个dialogFragment，询问我是否要删除LatLang对;如果用户确认，该对将从SQLite数据库中删除，从列表中删除，并重新填充列表。

在运行良好之后，我尝试重写代码以在SQLite数据库中包含另一列来保存LatLang对的String标签。但现在，当我点击一个LatLang对，而不是打开谷歌地图意图，没有任何反应。当我按住click然后确认删除时，应用程序崩溃并出现CursorIndexOutofBoundsException。我已经尝试过调试，进一步阅读这个，并检查stackoverflow存档，但我仍然不确定发生了什么。

如果有人看到任何明显的东西，请告诉我。我对编程一般都很陌生。

这是我的SQLite DatabaseHandler类：

package com.detimil.breadcrumbs1;

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;

public class DatabaseHandler extends SQLiteOpenHelper {

// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;

// Database Name
private static final String DATABASE_NAME = "breadcrumbsManager";

// Contacts table name
private static final String TABLE_BREADCRUMBS = "breadcrumbs";

// Contacts Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_LABEL = "longitude";
private static final String KEY_LATITUDE = "latitude";
private static final String KEY_LONGITUDE = "longitude";


public DatabaseHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_BREADCRUMBS_TABLE = "CREATE TABLE " + TABLE_BREADCRUMBS + "("
            + KEY_ID + " INTEGER PRIMARY KEY," + KEY_LABEL + " TEXT," + KEY_LATITUDE + " TEXT,"
            + KEY_LONGITUDE + " TEXT" + ")";
    db.execSQL(CREATE_BREADCRUMBS_TABLE);
}

// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // Drop older table if existed
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_BREADCRUMBS);

    // Create tables again
    onCreate(db);
}

/**
 * All CRUD(Create, Read, Update, Delete) Operations
 */


    // Adding new location/breadcrumb
public void addBreadcrumb(Breadcrumb breadcrumb) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_LABEL, breadcrumb.getBreadcrumbLabel()); // Label
        values.put(KEY_LATITUDE, breadcrumb.getBreadcrumbLatitude()); // Latitude
        values.put(KEY_LONGITUDE, breadcrumb.getBreadcrumbLongitude()); // Longitude

        // Inserting Row
        db.insert(TABLE_BREADCRUMBS, null, values);
        db.close(); // Closing database connection
    }


    // Getting single breadcrumb
public Breadcrumb getBreadcrumb(int id) {
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.query(TABLE_BREADCRUMBS, new String[] { KEY_ID, KEY_LABEL,
            KEY_LATITUDE, KEY_LONGITUDE }, KEY_ID + "=?",
            new String[] { String.valueOf(id) }, null, null, null, null);

//(I just edited this snippet as per advice from comment below. Unfortunately, the code still does not run correctly.)
if (cursor.getCount() > 0){
        cursor.moveToFirst();
}
        Breadcrumb breadcrumb = new Breadcrumb(Integer.parseInt(cursor.getString(0)), cursor.getString(1),
        cursor.getInt(2), cursor.getInt(3));
    // return breadcrumb
    cursor.close();
    return breadcrumb;
}


    // Getting All breadcrumbs
    public List<Breadcrumb> getAllBreadcrumbs() {
 List<Breadcrumb> breadcrumbList = new ArrayList<Breadcrumb>();
    // Select All Query
    String selectQuery = "SELECT  * FROM " + TABLE_BREADCRUMBS;

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Breadcrumb breadcrumb = new Breadcrumb();
            breadcrumb.setId(Integer.parseInt(cursor.getString(0)));
            breadcrumb.setBreadcrumbLabel(cursor.getString(1));
            breadcrumb.setBreadcrumbLatitude(cursor.getInt(2));
            breadcrumb.setBreadcrumbLongitude(cursor.getInt(3));
            // Adding location to list
            breadcrumbList.add(breadcrumb);
        } while (cursor.moveToNext());
    }

    // return locations list
    cursor.close();
    return breadcrumbList;
}

// Getting All breadcrumb labels (leaving out the Lats and Langs)
public List<Breadcrumb> getAllBreadcrumbLabels() {
 List<Breadcrumb> breadcrumbLabelList = new ArrayList<Breadcrumb>();
// Select All Query
String selectQuery = "SELECT  * FROM " + TABLE_BREADCRUMBS;

SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);

// looping through all rows and adding to list
if (cursor.moveToFirst()) {
    do {
        Breadcrumb breadcrumb = new Breadcrumb();
        breadcrumb.setId(Integer.parseInt(cursor.getString(0)));
        breadcrumb.setBreadcrumbLabel(cursor.getString(2));
        // Adding label to list
        breadcrumbLabelList.add(breadcrumb);
    } while (cursor.moveToNext());
}

// return locations list
cursor.close();
return breadcrumbLabelList;
}

// Getting breadcrumbs/locations Count
    public int getBreadcrumbsCount() {
        String countQuery = "SELECT  * FROM " + TABLE_BREADCRUMBS;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        cursor.close();

        // return count
        return cursor.getCount();
    }


      //Updating single location
    public int updateBreadcrumbs(Breadcrumb breadcrumb) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_LABEL, breadcrumb.getBreadcrumbLabel());
        values.put(KEY_LATITUDE, breadcrumb.getBreadcrumbLatitude());
        values.put(KEY_LONGITUDE, breadcrumb.getBreadcrumbLongitude());

         //updating row
        return db.update(TABLE_BREADCRUMBS, values, KEY_ID + " = ?",
              new String[] { String.valueOf(breadcrumb.getId()) });
    }

    // Deleting single location
      public void deleteBreadcrumb(Breadcrumb breadcrumb) {
        SQLiteDatabase db = this.getWritableDatabase();
        int id = breadcrumb.getId();
        System.out.println("Comment deleted with id: " + id);
        db.delete(TABLE_BREADCRUMBS, KEY_ID
                + " = " + id, null);
        db.close();
          }

}

这是我使用ListView的活动：

package com.detimil.breadcrumbs1;

import java.util.List;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;


public class CollectedBreadcrumbsActivity extends Activity {

private ListView listview;
private DatabaseHandler db;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_collected_breadcrumbs);

    db = new DatabaseHandler(this);
    List<Breadcrumb> breadcrumbs = db.getAllBreadcrumbLabels();

    listview = (ListView) findViewById(R.id.list);
    ArrayAdapter<Breadcrumb> adapter = new ArrayAdapter<Breadcrumb>(this,
            android.R.layout.simple_list_item_1, breadcrumbs);
        listview.setAdapter(adapter);

this.listview.setOnItemClickListener(new OnItemClickListener() {

public void onItemClick(AdapterView<?> l, View v, int position, long id) {

ArrayAdapter<Breadcrumb> adapter = (ArrayAdapter<Breadcrumb>) listview.getAdapter();
if (listview.getAdapter().getCount() > 0) {
    Breadcrumb breadcrumb = db.getBreadcrumb(position);

    final Intent intent = new Intent(Intent.ACTION_VIEW,Uri.parse("http://maps.google.com/maps" + "&daddr=" + breadcrumb.getBreadcrumbLatitude()/1e6 + "," + breadcrumb.getBreadcrumbLongitude()/1e6));
    intent.setClassName("com.google.android.apps.maps","com.google.android.maps.MapsActivity");
    startActivity(intent);}}});

this.listview.setOnItemLongClickListener(new OnItemLongClickListener() {

public boolean onItemLongClick(AdapterView<?> l, View v, final int position, long id) {
    Log.d("HelloListView", "You clicked Item: " + id + " at position:" + position);
    Log.d("HelloListView", "Number of items in adapter:" + listview.getAdapter().getCount());

    AlertDialog.Builder alertbox = new AlertDialog.Builder(CollectedBreadcrumbsActivity.this);

    // set the message to display
    alertbox.setMessage("Delete Breadcrumb?");

    // set a positive/yes button and create a listener
    alertbox.setPositiveButton("Delete", new DialogInterface.OnClickListener() {

        // do something when the button is clicked
        public void onClick(DialogInterface arg0, int arg1) {                
            @SuppressWarnings("unchecked")
            ArrayAdapter<Breadcrumb> adapter = (ArrayAdapter<Breadcrumb>) listview.getAdapter();
            if (listview.getAdapter().getCount() > 0) {
                Breadcrumb listedBreadcrumb = (Breadcrumb) listview.getAdapter().getItem(position);
                Breadcrumb breadcrumb = db.getBreadcrumb(position);
                db.deleteBreadcrumb(breadcrumb);
                adapter.remove(listedBreadcrumb);
                }
            adapter.notifyDataSetChanged();



        }
    });

    // set a negative/no button and create a listener
    alertbox.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

        // do something when the button is clicked
        public void onClick(DialogInterface arg0, int arg1) {
        }
    });

    alertbox.show();

    return true;
    }
});

listview.setEmptyView(findViewById(R.id.empty));
}
}

首先通过单击MainActivity中的按钮填充SQLite数据库。下面是代码片段，显示按下该按钮时会发生什么：它启动另一个活动，并且（理论上？）创建一个SQLite行，该行包含一个String Label，一个表示为int的Latitude和一个表示为an的经度INT。 

public void dropBreadcrumb(View view) {
    Intent intent = new Intent(this, DroppedCrumb.class);
    DatabaseHandler db = new DatabaseHandler(this);
    String label = "Breadcrumb"+db.getBreadcrumbsCount()+1; 
    BREADCRUMB_LATITUDE = (BREADCRUMB_LATITUDE * 1e6);
    int lat = (int)BREADCRUMB_LATITUDE;
    BREADCRUMB_LONGITUDE = (BREADCRUMB_LONGITUDE * 1e6);
    int lng = (int)BREADCRUMB_LONGITUDE;
    db.addBreadcrumb(new Breadcrumb(label, lat, lng));
    startActivity(intent);
}

这是当我持有listView项并确认我要删除它时获得的实际错误读数。该应用程序崩溃...... 

05-19 14:05:25.512: D/HelloListView(2086): You clicked Item: 0 at position:0
05-19 14:05:25.512: D/HelloListView(2086): Number of items in adapter:4
05-19 14:05:25.602: I/Adreno200-EGLSUB(2086): <ConfigWindowMatch:2087>: Format RGBA_8888.
05-19 14:05:26.653: W/dalvikvm(2086): threadid=1: thread exiting with uncaught exception ( (group=0x40e4c438)
05-19 14:05:26.663: E/AndroidRuntime(2086): FATAL EXCEPTION: main
05-19 14:05:26.663: E/AndroidRuntime(2086): android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 0
05-19 14:05:26.663: E/AndroidRuntime(2086):     at android.database.AbstractCursor.checkPosition(AbstractCursor.java:418)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:50)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at com.detimil.breadcrumbs1.DatabaseHandler.getBreadcrumb(DatabaseHandler.java:84)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at com.detimil.breadcrumbs1.CollectedBreadcrumbsActivity$2$1.onClick(CollectedBreadcrumbsActivity.java:72)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:167)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at android.os.Looper.loop(Looper.java:137)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at android.app.ActivityThread.main(ActivityThread.java:4950)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at java.lang.reflect.Method.invokeNative(Native Method)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at java.lang.reflect.Method.invoke(Method.java:511)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
05-19 14:05:26.663: E/AndroidRuntime(2086):     at dalvik.system.NativeStart.main(Native Method)

如果您有任何想法，我会非常感激。如果任何其他信息/代码对您有用，请告诉我。

非常感谢。

修改/更新

我刚刚根据用户nikhil的初始建议编辑了我的getBreadcrumb方法，但主要问题仍然存在。以下是我收到的错误消息...... 

05-20 17:48:48.966: D/HelloListView(15738): You clicked Item: 2 at position:2
05-20 17:48:48.966: D/HelloListView(15738): Number of items in adapter:4
05-20 17:48:49.056: I/Adreno200-EGLSUB(15738): <ConfigWindowMatch:2087>: Format RGBA_8888.
05-20 17:48:50.297: W/dalvikvm(15738): threadid=1: thread exiting with uncaught exception (group=0x414db438)
05-20 17:48:50.297: E/AndroidRuntime(15738): FATAL EXCEPTION: main
05-20 17:48:50.297: E/AndroidRuntime(15738): android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 0
05-20 17:48:50.297: E/AndroidRuntime(15738):    at android.database.AbstractCursor.checkPosition(AbstractCursor.java:418)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:50)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at com.detimil.breadcrumbs1.DatabaseHandler.getBreadcrumb(DatabaseHandler.java:86)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at com.detimil.breadcrumbs1.CollectedBreadcrumbsActivity$2$1.onClick(CollectedBreadcrumbsActivity.java:72)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:167)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at android.os.Looper.loop(Looper.java:137)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at android.app.ActivityThread.main(ActivityThread.java:4950)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at java.lang.reflect.Method.invokeNative(Native Method)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at java.lang.reflect.Method.invoke(Method.java:511)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
05-20 17:48:50.297: E/AndroidRuntime(15738):    at dalvik.system.NativeStart.main(Native Method)

2 个答案:

答案 0 :(得分：1)

您有2个名称经度相同的列

private static final String KEY_ID = "id";
private static final String KEY_LABEL = "longitude";
private static final String KEY_LATITUDE = "latitude";
private static final String KEY_LONGITUDE = "longitude";

答案 1 :(得分：0)

问题在于你的getBreadCrumb方法。 当您长按第一行时，位置变量为0（零），因此当您将此值传递给getBreadCrumb方法时，sql查询失败（这意味着它不返回任何数据），因为id（主键）始终以1开头这个问题是由于这个声明而来的： public Breadcrumb getBreadcrumb（int id）{     SQLiteDatabase db = this.getReadableDatabase（）; 

Cursor cursor = db.query(TABLE_BREADCRUMBS, new String[] { KEY_ID, KEY_LABEL,
        KEY_LATITUDE, KEY_LONGITUDE }, KEY_ID + "=?",
        new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor.getCount() > 0)
    cursor.moveToFirst();

    Breadcrumb breadcrumb = new Breadcrumb(Integer.parseInt(cursor.getString(0)), cursor.getString(1),

} if条件不满足，这就是为什么你的光标没有被移动到指向第一行的原因所以你在logcat中得到了错误。 修改后的代码是：

public Breadcrumb getBreadcrumb(int id) {
SQLiteDatabase db = this.getReadableDatabase();

Cursor cursor = db.query(TABLE_BREADCRUMBS, new String[] { KEY_ID, KEY_LABEL,
        KEY_LATITUDE, KEY_LONGITUDE }, KEY_ID + "=?",
        new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor.getCount() > 0)
   { 
       cursor.moveToFirst();
       Breadcrumb breadcrumb = new Breadcrumb(Integer.parseInt(cursor.getString(0),
       cursor.getString(1),cursor.getInt(2),cursor.getInt(3));
//  return breadcrumb
   }
       cursor.close();
       return breadcrumb;

}

注意if条件周围的问题。

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