사용자를 확인하는 방법

Question

사용자가 사용자 이름과 비밀번호를 입력하는 로깅 앱을 만들고 있습니다. 사용자 이름과 암호가 데이터베이스에있는 경우 사용자가 의도를 통해 새 페이지로 이동하면 오류가 발생합니다.

메인 페이지

package com.loginappdemo; 

import android.app.Activity; 
import android.content.Intent; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.EditText; 

public class MainPage extends Activity { 
    EditText un, pw; 
    Button login, register; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     final DataBaseHandler db = new DataBaseHandler(this); 
     un = (EditText) findViewById(R.id.username); 
     pw = (EditText) findViewById(R.id.password); 
     login = (Button) findViewById(R.id.login); 
     login.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View arg0) { 
       // TODO Auto-generated method stub 
       String a=un.getText().toString(); 
       String b=pw.getText().toString(); 
       String data=db.selectData(a, b); 


      } 
     }); 
     register = (Button) findViewById(R.id.register); 
     register.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       Intent i = new Intent(MainPage.this, NewLogin.class); 
       startActivity(i); 

      } 
     }); 

    } 
} 

DATABASEHANDLER 클래스는

package com.loginappdemo; 

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteDatabase.CursorFactory; 
import android.database.sqlite.SQLiteOpenHelper; 

public class DataBaseHandler extends SQLiteOpenHelper { 
    private static final String username = "username"; 
    private static final String password = "password"; 
    private static final String id = "id"; 
    private static final String db_name = "LOGINDEMO"; 
    private static final String table_name = "LOGINDETAILS"; 
    private static final int db_version = 1; 
    private static final String create_table = " CREATE TABLE " + table_name 
      + "(" + id + " INTEGER PRIMARY KEY AUTOINCREMENT, " + username 
      + " VARCHAR(200)," + password + " VARCHAR(200) " + ") "; 

    public DataBaseHandler(Context context) { 
     super(context, db_name, null, db_version); 
     // TODO Auto-generated constructor stub 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 

     // TODO Auto-generated method stub 
db.execSQL(create_table); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) { 
     // TODO Auto-generated method stub 

    } 
public long insertData(String name,String password1){ 
    SQLiteDatabase db=getWritableDatabase(); 
    ContentValues cv=new ContentValues(); 
    cv.put(username, name); 
    cv.put(password, password1); 
    long id=db.insert(table_name, null, cv); 
    return id; 

} 
public String selectData(String name,String password1){ 
    SQLiteDatabase db=getWritableDatabase(); 
    String[] col={ username, password}; 
    String[] args={ name, password1}; 
    StringBuffer b=new StringBuffer(); 
    Cursor cursor=db.query(table_name, col, username + " =? AND " +password+ " =? ", args, null, null, null); 
    String s1= cursor.getString(1); 
    String s2=cursor.getString(2); 
    b.append(s1 + " " + s2 + "\n"); 
    return b.toString(); 

} 
} 

Answer 1

는

boolean res = dbh.GetData(s1, s2); 
if(res == true) { 
    Intent in=new Intent(LoginActivity.this,nextActivity.class); 
    startActivity(in);      
} 
else {     
    Toast.makeText(MainActivity.this, "Login failed", Toast.LENGTH_SHORT).show(); 
} 

dbh이 DataBaseHandler 클래스 객체이며,이 방법을 시도하고

public boolean GetData(String uname, String pass) 
{ 
    SQLiteDatabase dbc = this.getReadableDatabase(); 
    Cursor c1 = dbc.query(
      TABLE_MIS2, 
      null, 
      DatabaseHandler.KEY_USERID + "=? AND " + DatabaseHandler.KEY_PWD + "=?", 
      new String[] { uname, pass }, 
      null, 
      null, 
      null); 
    return (c1.getCount() >= 1); 
} 

은 변수 변수 이름을 교체하고 시도.

Answer 2

당신은, 그것을 어느 쪽이든을 할 수

public int selectData(String name,String password1) 
{ 
    SQLiteDatabase db=getWritableDatabase(); 
    String[] col={ username, password}; 
    String[] args={ name, password1}; 
    StringBuffer b=new StringBuffer(); 
    Cursor cursor=db.query(table_name, col, username + " =? AND " +password+ " =? ", args, null, null, null); 
    cursor.moveToFirst(); 
    return cursor.getCount(); 
} 

방법 onClick()에서

if (db.selectData(a, b) > 0) 
{ 
    // Launch second Activity 
} 
else 
{ 
    // Display Toast Msg "Invalid Username/Password"; 
}