onCreate 不是 SQLiteOpenHelper 的构造函数，但我需要它用于 getIntet

Question

我需要使用 getIntent，但不能这样做，因为据我了解，它不是 SQLiteOpenHelper 的构造函数，并且 getIntent 需要在 onCreate 中使用。

在这种情况下，我如何从 SQLiteOpenHelper 中访问它？

基本上，我试图让以下代码在 SQLiteOpenHelper 中工作，但遇到了麻烦。

        public void onCreate(Bundle savedInstanceState) {
        onCreate(savedInstanceState);
        sortTypePassed=getIntent().getStringExtra(SmithRockScreenActivity.SORT_TYPE_VAR);
    }

我正在尝试根据 String 的值对数据库进行查询排序。就像这样：

  public Cursor getCursor() {



    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();

    queryBuilder.setTables(TABLE_NAME);

    String[] asColumnsToReturn = new String[] { COLUMN_ID, COLUMN_TITLE, COLUMN_YDSRATING, COLUMN_ROUTETYPE, COLUMN_AREA, COLUMN_ROUTEVIDEO, COLUMN_ROUTEDESCRIPTION};

    if (sortTypePassed.equals("nameSort")) { 

        Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
                null, null, null, "route_name ASC");

        return mCursor;

    } else {

        Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
                null, null, null, "yds_rating ASC");

        return mCursor;

    }

这是完整的代码：

package com.pocketbeta;


import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Locale;

import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteQueryBuilder;
import android.os.Bundle;
 import android.util.Log;


class SmithRockDatabase extends SQLiteOpenHelper {

public String sortTypePassed = "null";

private static final String DATABASE_PATH = "/data/data/com.pocketbeta/databases/";
private static final String DATABASE_NAME="smithrockdb.db";
private static final int SCHEMA_VERSION=1;
public static final String TABLE_NAME = "SmithRockRoutes";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_TITLE = "route_name";
public static final String COLUMN_YDSRATING = "yds_rating";
public static final String COLUMN_QUALITY = "quality";
public static final String COLUMN_IMAGE = "route_photo";
public static final String COLUMN_ROUTEVIDEO = "route_video";
public static final String COLUMN_TICKLIST = "ticklist";
public static final String COLUMN_AREA = "area";
public static final String COLUMN_ROUTETYPE = "route_type";
public static final String COLUMN_ROUTEDESCRIPTION = "route_description";

public SQLiteDatabase dbSqlite;

private final Context myContext;

public SmithRockDatabase(Context context) {
    super(context, DATABASE_NAME, null, SCHEMA_VERSION);
    this.myContext = context;
    // check if exists and copy database from resource
    //createDB();
}


@Override
public void onCreate(SQLiteDatabase db) {
    // check if exists and copy database from resource

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}
public void createDatabase() {
    createDB();
}

private void createDB() {

    boolean dbExist = DBExists();

    if (!dbExist) {

        //By calling this method we create an empty database into the default system location
        //We need this so we can overwrite that database with our database.
        this.getReadableDatabase();
        //now we copy the database we included!
        copyDBFromResource();


    }



}    

private boolean DBExists() {

    SQLiteDatabase db = null;

    try {
        String databasePath = DATABASE_PATH + DATABASE_NAME;
        db = SQLiteDatabase.openDatabase(databasePath, null,
                SQLiteDatabase.OPEN_READWRITE);
        db.setLocale(Locale.getDefault());
        db.setLockingEnabled(true);
        db.setVersion(1);



    } catch (SQLiteException e) {

        Log.e("SqlHelper", "database not found");

    }

    if (db != null) {


        db.close();

    }


    return db != null ? true : false;
}

private void copyDBFromResource() {

    InputStream inputStream = null;
    OutputStream outStream = null;
    String dbFilePath = DATABASE_PATH + DATABASE_NAME;

    try {

        inputStream = myContext.getAssets().open(DATABASE_NAME);

        outStream = new FileOutputStream(dbFilePath);

        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) > 0) {
            outStream.write(buffer, 0, length);
        }

        outStream.flush();
        outStream.close();
        inputStream.close();

    } catch (IOException e) {

        throw new Error("Problem copying database from resource file.");

    }

}

public void openDataBase() throws SQLException {

    String myPath = DATABASE_PATH + DATABASE_NAME;
    dbSqlite = SQLiteDatabase.openDatabase(myPath, null,
            SQLiteDatabase.OPEN_READWRITE);

}

@Override
public synchronized void close() {

    if (dbSqlite != null)
    {
        dbSqlite.close();
    }
    super.close();

}

// NEED TO GET THIS CODE TO WORK TO BRING IN VALUE FROM OTHER INTENT!!!!!!!!!!!!!!!!!!

//  public void onCreate(Bundle savedInstanceState) {
//  onCreate(savedInstanceState);
//  sortTypePassed=getIntent().getStringExtra(SmithRockScreenActivity.SORT_TYPE_VAR);
//}
// }


public Cursor getCursor() {



    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();

    queryBuilder.setTables(TABLE_NAME);

    String[] asColumnsToReturn = new String[] { COLUMN_ID, COLUMN_TITLE, COLUMN_YDSRATING, COLUMN_ROUTETYPE, COLUMN_AREA, COLUMN_ROUTEVIDEO, COLUMN_ROUTEDESCRIPTION};

    if (sortTypePassed.equals("nameSort")) { 

        Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
                null, null, null, "route_name ASC");

        return mCursor;

    } else {

        Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
                null, null, null, "yds_rating ASC");

        return mCursor;

    }

}


public String getName(Cursor c) {


    return(c.getString(1));

}

public String getRating(Cursor c) {
    return(c.getString(2));
}
public String getArea(Cursor c) {
    return(c.getString(4));
}
public String getRouteVideo(Cursor c) {
    return(c.getString(5));
}
public String getRouteDescription(Cursor c) {
    return(c.getString(6));
}

public String getRouteType(Cursor c) {

    String routeValue="";
    routeValue=(c.getString(3));
    String noSelection = "";

    if (routeValue != null) {
        return c.getString(3);

    } else {
        return(noSelection);

    }


}

}

Answer 1

既然如此，我如何从 SQLiteOpenHelper 中访问它？

理想情况下，您无法从 SQLiteOpenHelper 访问 getIntent()。您在 SQLiteOpenHelper 上实现一个构造函数（提示：您已经有了一个），并传入它需要的任何数据。理想情况下，这不涉及传递活动，而是涉及活动从任何地方获取的值（例如，Intent extras）。