Question

我正在尝试开发一个物理测验应用程序，但我不断收到错误

02-23 16:02:06.006: E/Database(9348): on sqlite3_open_v2("data/data/com.mcq.srm/databases/q.db", &handle, 1, NULL) failed

下面的代码段

public class QuestionPane extends Activity {
    int counter  =00;
    RadioButton radioButton;
    TextView Question;
    TextView tvScore;
    Button Next;

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

        int resdb=0;
        try {
            SQLiteDatabase checkDB = null;
             String DB_FULL_PATH = "data/data/com.mcq.srm/databases/q.db";
                checkDB = SQLiteDatabase.openDatabase(DB_FULL_PATH, null,
                        SQLiteDatabase.OPEN_READONLY);
                checkDB.close();
                //Toast.makeText(this,"db  "+checkDB, Toast.LENGTH_LONG).show();
                resdb=0;
                Log.v("msg","Database created");

        } catch (Exception e){
            resdb=1;    
        }
        Log.v("msg", "check res-->"+resdb);
        try{
        db = openOrCreateDatabase("q.db" , SQLiteDatabase.CREATE_IF_NECESSARY , null );
            if(resdb==1)
            {
                Log.v("msg","creating tables");
                CreateTable();
                InsertData();   
                displayres();
            }
        }
        catch(Exception e){
        }
    }

    public void CreateTable(){
        String Createtab;
          Createtab =" CREATE TABLE tbl_Question ("+ "_id INTEGER PRIMARY KEY AUTOINCREMENT, Questions TEXT, option_1 TEXT,option_2 TEXT, option_3 Text, option_4 TEXT, correct_answer TEXT);";
        try{
            db.execSQL(Createtab);

        }
        catch(Exception e){
        }   
  }
  public void InsertData(){
     ContentValues values = new ContentValues();

    values.put("question", "Two beams of red and violet colours are made to pass separately through a prism of A = 60°. In the minimum deviation position, the angle of refraction inside the prism will be");
    //... value.put statements removed
       db.insert("tbl_Question", null, values);

       //.. values.put statements removed
       values.put("correct_answer","35 grams");
       db.insert("tbl_Question", null, values);
   }
   public void displayres() {
            int qno=1;

            String sql1="select * from  question;";

            Cursor c1=db.rawQuery(sql1,null);
            Log.v("answer","asd");
              String que,opt1,opt2,opt3,opt4;

              startManagingCursor(c1);
              c1.moveToFirst();
              que=c1.getString(c1.getColumnIndex("Question1"));
              Log.v("answer",que);
        }
}

Answer 1

你有很多错误我建议你通过this示例，最好从android中的那个例子开始。你需要为Database创建单独的类，一般称为数据库适配器和一个这是Android Devs的Database Helper。因此，要获得完整的想法，请通过该示例。

需要帮助开发Android的测验应用程序

1 个答案: