java - 制作一个显示前 10 名玩家的排行榜？

Question

我创建的排行榜有问题，该排行榜是为了显示得分最高的前 10 名玩家，但它以相反的顺序首先显示最低的玩家，我尝试更改选择语句和版本数据库并且不起作用有人知道如何解决这个问题吗？这是排行榜 Activity :

package com.example.tabsnav;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.List;

import library.DBhelper;
import library.DBhelper.DatabaseHelper;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

public class LeaderBoard extends Activity {
ArrayList<Leaders> imageArry = new ArrayList<Leaders>();
ImageAdapter adapter;
EditText etcomment1;
//Button b1;
DBhelper db;
TextView etname1;
ListView dataList;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.leader_board);




}

    @Override
 protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    adapter.clear();
}
 @Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
db = new DBhelper(this);
db.open();


// Reading all comments from database

List<Leaders> contacts = db.getAllContactsFromAndroid();

for (Leaders cn : contacts) {
    String log = "ID:" + cn.getID() + " Name: " + cn.getName()
            + " ,Image: " + cn.getImage();

    // Writing Contacts to log
    Log.d("Result: ", log);
    //add contacts data in arrayList
    imageArry.add(cn);

}
adapter = new ImageAdapter(this, R.layout.leader_list_adapter,
        imageArry);
dataList = (ListView) findViewById(R.id.list);
dataList.setAdapter(adapter);
}}

我在数据库中的获取函数:

// Getting All Contacts From Android
public List<Leaders> getAllContactsFromAndroid() {
    List<Leaders> contactList = new ArrayList<Leaders>();
    // Select All Query
    Cursor cursor=null;
    cursor = mDb.rawQuery("SELECT  * FROM Game DESC ORDER by score LIMIT 10",
            null);
    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Leaders contact = new Leaders();
            contact.setName(cursor.getString(cursor.getColumnIndex(G_FIRSTNAME)));
            contact.setImage(cursor.getBlob(cursor.getColumnIndex(G_PHOTO)));
            contact.setComment(cursor.getInt(cursor.getColumnIndex(G_SCORE)));
            // Adding contact to list
            contactList.add(contact);
        } while (cursor.moveToNext());
    }

用于设置和获取数据的领导者类:

package com.example.tabsnav;

public class Leaders {

// private variables
int _id;
String _name;
byte[] _image;
int _comment;

// Empty constructor
public Leaders() {

}
// constructor
    public Leaders(int keyId, String name, byte[] image,int comment) {
        this._id = keyId;
        this._name = name;
        this._image = image;
        this._comment=comment;

    }

// constructor
public Leaders(int keyId, String name, byte[] image) {
    this._id = keyId;
    this._name = name;
    this._image = image;

}

// constructor
public Leaders(String contactID, String name, byte[] image) {
    this._name = name;
    this._image = image;

}

// constructor
public Leaders(String name, byte[] image) {
    this._name = name;
    this._image = image;
}


// getting ID
public int getID() {
    return this._id;
}

// setting id
public void setID(int keyId) {
    this._id = keyId;
}

// getting name
public String getName() {
    return this._name;
}

// setting name
public void setName(String name) {
    this._name = name;
}

// getting phone number
public byte[] getImage() {
    return this._image;
}

// setting phone number
public void setImage(byte[] image) {
    this._image = image;
}

// getting comment
public int getComment() {
    return this._comment;
}

// setting comment
public void setComment(int comment) {
    this._comment = comment;
}
}

这是排行榜的屏幕截图:

Answer 1

试试这个:mDb.query(DATABASE_TABLE, new String[] { KEY_NAME, KEY_SCORE}, null, null, null, null,KEY_SCORE+"DESC","LIMIT 10");