how to validate login?

Question

how to validate in login form that username and password is not matching ?? or username not exists or password is wrong

Satyapriya Nayak · Answer

Hi Hemant, using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Data.OleDb; namespace Login_page_Msaccess { public partial class Form1 : Form { string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"]; OleDbCommand com; string str; object obj = null; public Form1() { InitializeComponent(); } private void btn_login_Click(object sender, EventArgs e) { OleDbConnection con = new OleDbConnection(ConnectionString); con.Open(); str = "select count(*) from login where UserName=@UserName and Password =@Password"; com = new OleDbCommand(str, con); com.CommandType = CommandType.Text; com.Parameters.AddWithValue("@UserName", TextBox_user_name.Text); com.Parameters.AddWithValue("@Password", TextBox_password.Text); obj = com.ExecuteScalar(); if ((int)(obj) != 0) { lb1.Text = "WELLCOME :: " + TextBox_user_name.Text; } else { lb1.Text = "invalid user name and password"; } con.Close(); } } } Thanks

Vilas Gite · Answer

HI HEMANT KUMAR CONTROLS : 2 LABLE, 2 TEXTBOX, 2 BUTTONS private void btnLogin_Click(object sender, EventArgs e) { try { if (txtLogin.Text == "ADMIN" && txtPass.Text == "PASS") { btnLogin.Enabled = false; txtLogin.Clear(); txtPass.Clear(); txtLogin.Enabled = false; txtPass.Enabled = false; } else { MessageBox.Show("Please Enter Right Username and Password", "Login Authentication", MessageBoxButtons.RetryCancel, MessageBoxIcon.Question); } } catch { MessageBox.Show("System Error"); } } private void btnExit_Click(object sender, EventArgs e) { this.Close(); } }

how to validate login?

Answers (2)