我有这个DataBaseCreator Java FIle。
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DataBaseCreator extends SQLiteOpenHelper {
private static String DB_PATH = "/GetInspiredAndHaveFun/assets/Jokes.db";
private static String DB_NAME = "Jokes.db";
private static int DB_VERSION = 1;
public static String DATABASE_TABLE = "myjoke";
public String temp = "";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DataBaseCreator(Context context) {
super(context, DB_NAME, null, DB_VERSION);
this.myContext = context;
}
public void openDatabase() throws IOException {
boolean dbe = checkDataBase();
if (dbe) {
Log.i("Tag", "dbe" + dbe);
} else {
Log.i("Tag", "dbdoesnotexist" + dbe);
this.getReadableDatabase();
copyDataBase();
}
}
public void copyDataBase() throws IOException {
InputStream inp = myContext.getAssets().open(DB_NAME);
String ofn = DB_PATH + DB_NAME;
OutputStream oup = new FileOutputStream(ofn);
byte[] buffer = new byte[1024];
int length;
while ((length = inp.read(buffer)) > 0) {
oup.write(buffer, 0, length);
}
oup.flush();
inp.close();
oup.close();
}
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
catch (SQLiteException e) {
}
return checkDB != null ? true : false;
}
public void openDataBase() throws SQLException {
// Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
passText();
}
public final String passText() {
Cursor cursor = myDataBase.query(DATABASE_TABLE, null, null, null,
null, null, null);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
temp += cursor.getString(1);
cursor.moveToNext();
}
return temp;
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
我想要的是将我的Jokes活动中的textview文本设置为passText9方法返回的字符串。但是,我收到了一个错误。 “temp”无法解析为变量。
主档
import java.io.IOException;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.os.Build;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
{
DataBaseCreator myDbHelper = new DataBaseCreator(this);
try{
myDbHelper.copyDataBase();
}
catch (IOException ioe) {
throw new Error("Unable to create database");
}
myDbHelper.openDataBase();
//here.
t1.setText(temp);
}
}
答案 0 :(得分:1)
temp是DataHelper实例的成员:
t1.setText(myDbHelper.temp);