Question

我有一个使用sqlite数据库的Android应用程序。我有一个可绘制文件夹中的图像，我需要在列表中显示。

我的问题是如何使用SQLite数据库中的文件名从drawable文件夹中检索图像？

这是我用来将图像添加到列表视图的代码：

package com.devleb.expandablelistdemo3;

import java.util.ArrayList;

import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v4.widget.SimpleCursorAdapter;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class MatchScheduleList extends Activity {

    private static final String DB_NAME = "world_cup.db";
    // *****Tables name**************************//
    private static final String TABLE_NAME = "match_list";

    // *****Tbale name******************************//

    public static final String PLACE_ID = "_id";
    public static final String STAD_NAME = "stad_name";
    public static final String TEAM1 = "team1";
    public static final String TEAM2 = "team2";
    public static final String STAGE = "stage";
    public static final String MATCH_DATE = "match_date";
    public static final String[] ALL_KEYS = new String[] { PLACE_ID, STAD_NAME,
            TEAM1, TEAM2, STAGE, MATCH_DATE };
    // *****Tbale name******************************//

    private SQLiteDatabase database;
    private ListView listView;
    private ArrayList<String> matchList;

    private ExternalDbOpenHelper extDB;

    int[] img = { R.drawable.brazil_flag, R.drawable.croatian_flag,
            R.drawable.mexico_flag, R.drawable.cameroon_flag, R.drawable.spain,
            R.drawable.netherlands_flag, R.drawable.czech_republic_flag,
            R.drawable.australia, R.drawable.colombia_flag, R.drawable.gress,
            R.drawable.cote_divoire_flag, R.drawable.japan,
            R.drawable.uruguay_flag, R.drawable.costa_rica_flag,
            R.drawable.england_flag, R.drawable.italy_flag,
            R.drawable.switzerland, R.drawable.ecuador_flag,
            R.drawable.france_flag, R.drawable.honduras_flag,
            R.drawable.argentina_flag, R.drawable.bousna, R.drawable.iran_flag,
            R.drawable.nigeria_flag, R.drawable.germany_flag,
            R.drawable.portugal, R.drawable.ghana_flag,
            R.drawable.united_states_flag, R.drawable.belgium_flag,
            R.drawable.algeria_flag, R.drawable.russia_flag,
            R.drawable.korea_flag };

    int nextImageIndex = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_match_schedule_list);

        ExternalDbOpenHelper extDB = new ExternalDbOpenHelper(this, DB_NAME);
        database = extDB.openDataBase();

        int imgid = img[nextImageIndex];
        nextImageIndex = (nextImageIndex + 1) % img.length;

        populateLitsFromDB();
    }


    public Cursor getAllRows() {
        String where = null;

        Cursor c = database.query(true, TABLE_NAME, ALL_KEYS, where, null,
                null, null, null, null);
        if (c != null) {
            c.moveToFirst();

        }

        return c;

    }

    private void populateLitsFromDB() {
        // TODO Auto-generated method stub

        Cursor cursor = getAllRows();

        // allo0w activity to manage life cicle of the cursor

        startManagingCursor(cursor);

        // setup mapping from cursor to view fields
        String[] fromFieldNames = new String[] { MATCH_DATE, TEAM1, TEAM2,STAD_NAME};
        int[] toViewFields = new int[] { R.id.txtDate, R.id.textName1, R.id.textName2, R.id.textLocation};

        // create adapter to map columns of the DB INTO ELEMENT IN THE LIST
        SimpleCursorAdapter myCursorAdapter = new SimpleCursorAdapter(this,
                R.layout.row_list_match_schedule, cursor, fromFieldNames,
                toViewFields);

        Log.d("in the getAllRows", myCursorAdapter.toString());

        // set the adapter for te listView
        ListView myList = (ListView) findViewById(R.id.list);
        myList.setAdapter(myCursorAdapter);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.match_schedule_list, menu);
        return true;
    }

}

Answer 1

好了，因为你知道所有可绘制的ID和团队名称是什么，为什么不尝试使用枚举？

例如

public enum TeamInfo {
    BRAZIL("brazil", R.drawable.brazil_flag),
    CROATIA("croatia", R.drawable.croatian_flag),
    MEXICO("mexico", R.drawable.mexican_flag);
    // Continue here

    private String name;
    private int resId;
    TeamInfo(int name, int resId){
        this.name = name;
        this.resId = resId;
    }
    public String getName(){
        return name;
    }
    public int getResId(){
        return resId;
    }
    public TeamInfo getTeamInfoByName(String nameToCompare){
        for(TeamInfo i : TeamInfo.values()){
            if(i.getName().equalsIgnoreCase(nameToCompare)) return i;
        }
        return null;
    }
}

然后，您可以将名称映射到各自的资源ID，并返回正确的TeamInfo和资源ID，如下所示：

TeamInfo team = TeamInfo.getTeamInfoByName(name_of_the_team);
int teamFlagResourceId = team.getResId();

我有可绘制文件夹中的图像，我需要使用它与mysql存储，并检索如何做到这一点？

1 个答案: