光標錯誤：確保光標從它

Question

訪問數據時，我進入數據庫中現有的RegID我得到這個錯誤之前正確初始化..

**DatabaseHandler.java** 
package com.example.aaqib.scoolbag; 

import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.content.Context; 

import android.database.sqlite.SQLiteException; 
import android.database.sqlite.SQLiteOpenHelper; 

     import android.util.Log; 


public class DatabaseHandler extends SQLiteOpenHelper { 
//Creating a Database ScoolBag 
    SQLiteDatabase mDb; 
    private static final int DATABASE_VERSION = 1; 
    private static final String DATABASE_NAME = "ScoolBag"; 
    public static final String KEY_NAME = "Name"; 
    public static final String KEY_MOBILENO = "Contact"; 
    public static final String KEY_REGID = "Registration"; 
    public static final String KEY_EMAIL = "Email"; 
    public static final String KEY_PASSWORD = "Password"; 
    // Table name 
    public static final String tblReg="tblReg"; 

    public DatabaseHandler(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 

     String vQuery = "Create Table " + tblReg + "(Registration Text primary key,Name Text not null,Password Text not null,Email Text not null,Contact Text not null)"; 
     Log.d("StudentData", "onCreate: " + vQuery); 
     db.execSQL(vQuery); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL("DROP TABLE IF EXISTS tblReg"); 
     onCreate(db); 
    } 
//using to insert 
    public void InsertRecord(String vInsertRecord) { 
     SQLiteDatabase db = this.getWritableDatabase(); 
     db.execSQL(vInsertRecord); 
     db.close(); 
    } 

    public void close() 

    { 
     mDb.close(); 
    } 

    /*public Cursor login(String regid)throws SQLiteException 
    { 
     String where =(KEY_REGID + "=?"); 
     Cursor m = mDb.query(true, tblReg, new String[]{KEY_REGID, KEY_NAME, KEY_PASSWORD,KEY_EMAIL,KEY_MOBILENO}, where, new String[]{regid}, null, null, null, null); 
     if (m != null) { 
      // m.moveToFirst(); 
     } 
     return m; 
    }*/ 


//fetching a emailid 
    public Cursor getEmailid(String email)throws SQLiteException 
    { 
     String where =(KEY_EMAIL + "=?"); 
     Cursor m = mDb.query(true,tblReg, new String[]{KEY_REGID, KEY_NAME, KEY_PASSWORD,KEY_EMAIL,KEY_MOBILENO}, where, new String[]{email}, null, null, null, null); 
     if (m != null) { 
     } 
     return m; 
    } 
//fetching cursor id 
    public Cursor getRegid(String reg)throws SQLiteException 
    { 
     String where =(KEY_REGID + "=?"); 
     Cursor j = mDb.query(true, tblReg, new String[]{KEY_REGID, KEY_NAME, KEY_PASSWORD,KEY_EMAIL,KEY_MOBILENO}, where, new String[]{reg}, null, null, null, null); 
     if (j!= null) { 
      //j.moveToFirst(); 
     } 
     return j; 
    } 





    public DatabaseHandler open() throws SQLiteException { 
     mDb = getWritableDatabase(); 
     return this; 
    } 
} 

acitivity_registration.java

package com.example.aaqib.scoolbag; 

import android.app.Activity; 
import android.content.Intent; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.Toast; 

import static android.view.View.OnClickListener; 


public class activity_registration extends Activity { 
    EditText reg, Name, Pas1, Pas2, Email, Contact; 
    String regid,emailid; 
    SQLiteDatabase db; 
    DatabaseHandler dbh = new DatabaseHandler(this); 







    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_activity_registration); 
     reg = (EditText) findViewById(R.id.editText); 
     Name = (EditText) findViewById(R.id.editText2); 
     Pas1 = (EditText) findViewById(R.id.editText3); 
     Pas2 = (EditText) findViewById(R.id.editText4); 
     Email = (EditText) findViewById(R.id.editText5); 
     Contact = (EditText) findViewById(R.id.editText6); 
     Button btnReg = (Button) findViewById(R.id.btnRegister); 

//button used to register 

      btnReg.setOnClickListener(new View.OnClickListener() { 


       @Override 
       public void onClick(View v) { 

        dbh.open(); 
try { 
    //get the id from database 
    dbh.open(); 
    Cursor c=dbh.getRegid(reg.getText().toString().trim()); 
    if((c != null) && c.moveToFirst()) 
    { 
     regid = c.getString(c.getColumnIndex("RegId")); 
     c.close(); 
    } 
    //get the email id from database 
    Cursor email = dbh.getEmailid(Email.getText().toString().trim()); 
    if (email != null && email.moveToFirst()) { 
     emailid = email.getString(email.getColumnIndex("Email")); 
     email.close(); 
    } 


    if (reg.getText().toString().equals("") || Name.getText().toString().equals("") || Pas1.getText().toString().equals("") || Pas2.getText().toString().equals("") || Email.getText().toString().equals("") || Contact.getText().toString().equals("")) { 
     Toast.makeText(getApplicationContext(), "Fill All Mandatory Fields", Toast.LENGTH_SHORT).show(); 
    } 
    else if (!Email.getText().toString().trim().matches("[a-zA-Z0-9._-]+@[a-z]+.[a-z]+")) 
    { 
     Email.setError("Invalid Email Address"); 
     Email.requestFocus(); 
    } 
    else if (Email.getText().toString().equals(emailid)) 
    { 
     Toast.makeText(getApplicationContext(), "Email is already registered", Toast.LENGTH_SHORT).show(); 
    } 
    else if (Email.getText().toString().equals(regid)) 
    { 
     Toast.makeText(getApplicationContext(), "Registration Id already exist", Toast.LENGTH_SHORT).show(); 
    } 
    else if (!Contact.getText().toString().trim().matches("^[0-9]{10}$")) { 
     Contact.setError("Invalid Contact Number"); 
     Contact.requestFocus(); 
    } 
    else if (!Name.getText().toString().trim().matches("([a-zA-Z ]+)$")) { 

     Name.setError("Invalid Name"); 
     Name.requestFocus(); 
    } 
    else if (!Pas1.getText().toString().trim().matches(Pas2.getText().toString().trim())) { 
     Pas2.setError("Password Not Matched"); 
     Pas2.requestFocus(); 
    } 
    else { 

     InsertRecord(); 
     Refresh(); 
     Intent i = new Intent(activity_registration.this, activity_home.class); 
     startActivity(i); 
     finish(); 
    } 
} 
catch (Exception e) 
{ 
    String ex=e.toString(); 
    Toast.makeText(getApplicationContext(), ex, Toast.LENGTH_SHORT).show(); 
} 
       } 


       }); 
      } 



    public void InsertRecord() 

    { 
     String vQuery = "insert into tblReg (Registration,Name,Password,Email,Contact)values('" + reg.getText().toString().trim() + "','" + Name.getText().toString().trim() + "','"+ Pas2.getText().toString().trim()+"','"+ Email.getText().toString().trim()+"','"+ Contact.getText().toString().trim() +"')"; 
     DatabaseHandler db = new DatabaseHandler(this); 
     db.InsertRecord(vQuery); 
     Toast.makeText(getApplicationContext(), "Inserted successful", Toast.LENGTH_SHORT).show(); 
    } 

    public void Refresh() 
    { 
     reg.setText(""); 
     Name.setText(""); 
     Pas1.setText(""); 
     Pas2.setText(""); 
     Email.setText(""); 
     Contact.setText(""); 
    } 

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

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 
     if (id == R.id.action_settings) { 
      return true; 
     } 
     return super.onOptionsItemSelected(item); 
    } 
} 

任何幫助，將不勝感激。

Answer 1

在你的表沒有列RegId以下行

regid = c.getString(c.getColumnIndex("RegId")); 

所以改爲

regid = c.getString(c.getColumnIndex("Registration")); 

希望這將幫助你。