android - 单击登录按钮android时从现有数据库验证用户名和密码

Question

亲爱的，当我单击注册时，我的主视图中有两个按钮“注册”和“登录”，然后当我单击按钮时，下一个 View 加载了两个文本框字段“用户名”和“密码”以及一个提交按钮我正在将数据发送到数据库并通过在 buttonclick() 事件中使用 finish() 返回到我的主要 Activity 。现在，当我单击登录按钮时，它会打开下一个 View 用户名和密码，当我填写它并单击提交按钮时，它会强制关闭..我在我的内容提供商数据库中使用 validate() 方法...所以我无法找到bug 请查看我的代码并帮助我...谢谢 adv.另一个问题是如何检查是否将数据插入数据库...

我的内容提供者类是

    public class MyContentProvider extends ContentProvider {

private SQLiteDatabase sqlDB;

public DatabaseHelper dbHelper;

private static final String DATABASE_NAME = "Users.db";

private static final int DATABASE_VERSION = 1;

private static final String TABLE_NAME = "User";

private static final String TAG = "MyContentProvider";

public static class DatabaseHelper extends SQLiteOpenHelper {

//public String USER_NAME;
//public String PASSWORDS;
 DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // create table to store user names
        db.execSQL("Create table "
                + TABLE_NAME
                + "( _id INTEGER PRIMARY KEY AUTOINCREMENT, USER_NAME TEXT,PASSWORDS TEXT);");
    }
    public boolean validateUser(String username, String password){
           Cursor c = getReadableDatabase().rawQuery(
                    "SELECT * FROM " + TABLE_NAME + " WHERE "
                            + MyUsers.User.USER_NAME + "='" + username +"'AND "+MyUsers.User.Pass+"='"+password+"'" ,  null);
           if (c.getCount()>0)
              return true;
              return false;
        }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }

}
@Override
public int delete(Uri uri, String s, String[] as) {
    return 0;
}
@Override
public String getType(Uri uri) {
    return null;
}

@Override
public Uri insert(Uri uri, ContentValues contentvalues) {
    // get database to insert records
    sqlDB = dbHelper.getWritableDatabase();
    // insert record in user table and get the row number of recently inserted record
    long rowId = sqlDB.insert(TABLE_NAME, "",contentvalues);
    if (rowId > 0) {
        Uri rowUri = ContentUris.appendId(
                MyUsers.User.CONTENT_URI.buildUpon(), rowId).build();
        getContext().getContentResolver().notifyChange(rowUri, null);
        return rowUri;
    }
    throw new SQLException("Failed to insert row into " + uri);
}


@Override
public boolean onCreate() {
    dbHelper = new DatabaseHelper(getContext());
    return (dbHelper == null) ? false : true;
}

@Override
public Cursor query(Uri uri, String[] projection, String selection,
        String[] selectionArgs, String sortOrder) {
    SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
    SQLiteDatabase db = dbHelper.getReadableDatabase();
    qb.setTables(TABLE_NAME);
    Cursor c = qb.query(db, projection, selection, null, null, null,
            sortOrder);
    c.setNotificationUri(getContext().getContentResolver(), uri);
    return c;
}


@Override
public int update(Uri uri, ContentValues contentvalues, String s,
        String[] as) {
    return 0;
}

我的用户类是

public class MyUsers {
public static DatabaseHelper dbHelper;
static final String TABLE_NAME = "User";

public static final String AUTHORITY = "com.linkwithweb.providers.MyContentProvider";

// BaseColumn contains _id.
public static final class User implements BaseColumns {

    public static final Uri CONTENT_URI = Uri
            .parse("content://com.linkwithweb.providers.MyContentProvider");

    // Table column
    public static final String USER_NAME = "USER_NAME";
    public static final String Pass = "Pass";


}

登录页面类是:

 public class loginpage extends Activity
 {

// DatabaseHelper dbHelper;
DatabaseHelper dbHelper=new DatabaseHelper(loginpage.this); 



@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.loginpage);
    Button button3 = (Button) findViewById(R.id.button3);
    button3.setOnClickListener(new View.OnClickListener() {
    public void onClick(View view) {
         EditText etext = (EditText) findViewById(R.id.editText);
         String  Name=( etext.getText().toString());
         EditText etext2 = (EditText) findViewById(R.id.editText3);
         String  Password    =( etext2.getText().toString());
         Log.i("saurabh ..",Name);
        if (dbHelper.validateUser(Name,Password))
        {
            Intent i = new Intent(loginpage.this,welcome.class);
            startActivity(i);

        }
      //else
     //Toast.makeText(getBaseContext(), "Wrong username/password", Toast.LENGTH_LONG).show();   
        }
    });
        }

注册页面是:::

  public class signform extends Activity
 {

MyAdapter mAdapter=null;
DatabaseHelper dbHelper;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.loginform);

    Button button1 = (Button) findViewById(R.id.button1);
    button1.setOnClickListener(new View.OnClickListener() {
    public void onClick(View view) {
          EditText etext = (EditText) findViewById(R.id.editText1);
          String Names=( etext.getText().toString());
          EditText etext2 = (EditText) findViewById(R.id.editText3);
          String Password    =( etext2.getText().toString());
          **mAdapter.insertRecord(Names,Password)**;
            finish();
        }

    });
    mAdapter = new MyAdapter(this);
  }
class MyAdapter extends BaseAdapter implements OnClickListener
 {

                private LayoutInflater inflater;

                public MyAdapter(Context ctx) {
                    super();
                    this.inflater = (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                }        




               public void insertRecord(String unames,String Passw) {
                    ContentValues values = new ContentValues();
                    values.put(MyUsers.User.USER_NAME, unames);
                    values.put(MyUsers.User.Pass, Passw);
                    getContentResolver().insert(MyUsers.User.CONTENT_URI, values);
                    notifyDataSetChanged();
                    Log.i("check for data insertion.......", "data inserted succesfully");
                   }

请检查为什么点击按钮不执行登录..谢谢

修改后请看我的log cat

07-01 12:17:32.911: ERROR/AndroidRuntime(600): Uncaught handler: thread main exiting due to uncaught exception
07-01 12:17:32.940: ERROR/AndroidRuntime(600): android.database.sqlite.SQLiteException: no such column: Pass: , while compiling: SELECT * FROM User WHERE USER_NAME='first names'AND Pass='last names'
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteProgram.native_compile(Native Method)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteProgram.compile(SQLiteProgram.java:110)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:49)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1220)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1193)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at com.linkwithweb.providers.MyContentProvider$DatabaseHelper.validateUser(MyContentProvider.java:45)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at loginapp.page.loginpage$1.onClick(loginpage.java:29)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.View.performClick(View.java:2364)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.View.onTouchEvent(View.java:4179)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.widget.TextView.onTouchEvent(TextView.java:6540)
  07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.View.dispatchTouchEvent(View.java:3709)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)
 07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.app.Activity.dispatchTouchEvent(Activity.java:2061)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1691)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.os.Looper.loop(Looper.java:123)
07-01 12:17:32.940: ERROR/AndroidRuntime(600):     at android.app.ActivityThread.main(ActivityThread.java:4363)

Answer 1

在您的登录页面 Activity 中，您调用了 dbHelper.validateUser(Name,Password)。但您没有使用 dbHelper。

写

dbHelper=new DatabaseHelper(this); 

在调用 dbHelper.validateUser(); 之前

当您创建表时，您将列定义为 PASSWORD。也就是说，您的列名称是 PASSWORD。但是当您进行查询时，您正在查询

"SELECT * FROM " + TABLE_NAME + " WHERE "
                            + MyUsers.User.USER_NAME + "='" + username +"'AND "+MyUsers.User.Pass+

MyUsers.User.Pass 的值是 Pass，不是 PASSWORD。所以你遇到了问题。请更正列名。希望你完成了