Simple Login Form In Desktop Application Using WinForm

In this blog, you will learn how to create a simple login form using WinForm while developing a desktop application.

In a desktop application, we also need a login form just like in a web application. I have developed a simple login page in the desktop using Windows Forms. 

 

Login Form Sample

 

 

Database Table

CREATE TABLE [dbo].[UserLogin](
   [UserID] [INT] IDENTITY(1,1) NOT NULL,
   [Username] [VARCHAR](50) NOT NULL,
   [Password] [NVARCHAR](250) NOT NULL,
   [PasswordSalt] [VARCHAR](50) NULL,
   [IsActive] [BIT] NOT NULL,
   [AddedOn] [DATETIME] NOT NULL,
CONSTRAINT [PK_UserLogin] PRIMARY KEY CLUSTERED
(
   [UserID] ASC
   )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[UserLogin] ADD CONSTRAINT [DF_UserLogin_IsActive] DEFAULT ((0)) FOR [IsActive]
GO

Stored Procedure:
-- =============================================
-- Author:  <Bhuban Rana>
-- Create date: <2018-12-24>
-- Description: <This Sp checks valid user in userlogin table>
-- =============================================
ALTER PROCEDURE [dbo].[usp_CheckValidUser]
@Username varchar(100),
@Password nvarchar(250)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE @Message varchar(100),
@Data nvarchar(250),
@Success bit
IF EXISTS(SELECT * FROM UserLogin WHERE Username=@Username AND [Password]=@Password)
BEGIN
SET @Success=1;
SET @Message='Valid User';
END
ELSE
BEGIN
SET @Success=0;
SET @Message='Incorrect Username or Password!';
END
SELECT @Success AS Success,@Message AS [Message]
END

In Service Class,

public ResponseModel Login(LoginModel model) {
    ResponseModel response = new ResponseModel();
    try {
        using(IDbConnection connection = DbConnection.DbConnect()) {
            DynamicParameters parameters = new DynamicParameters();
            parameters.Add("@Username", model.Username);
            parameters.Add("@Password", model.Password);
            response = SqlMapper.Query < ResponseModel > (connection, "[dbo].[usp_CheckValidUser]", parameters, commandType: CommandType.StoredProcedure).FirstOrDefault();
        }
    } catch (Exception ex) {
        response.Success = false;
        response.Message = ex.Message.ToString();
    }
    return response;
}

In Controller,

public class LoginController {
    private LoginService _loginService;
    public LoginController() {
        _loginService = new LoginService();
    }
}

Events

private void btnLogin_Click(object sender, EventArgs e) {
    progressBar.Minimum = 0;
    progressBar.Maximum = 100;
    progressBar.Value = 10;
    progressBar.Step = 10;
    lblRequiredUname.Visible = false;
    lblRequiredPwd.Visible = false;
    if (string.IsNullOrEmpty(txtUsername.Text) && string.IsNullOrEmpty(txtPassword.Text)) {
        lblRequiredUname.Visible = true;
        lblRequiredPwd.Visible = true;
    } else if (string.IsNullOrEmpty(txtUsername.Text.Trim())) {
        lblRequiredUname.Visible = true;
    } else if (string.IsNullOrEmpty(txtPassword.Text.Trim())) {
        lblRequiredPwd.Visible = true;
    } else {
        progressBar.Visible = true;
        if (!bgWorker.IsBusy) {
            btnLogin.Enabled = false;
            progressBar.Style = ProgressBarStyle.Marquee;
            bgWorker.RunWorkerAsync();
        }
    }
}
private void bgWorker_DoWork(object sender, DoWorkEventArgs e) {
    ResponseModel response = new ResponseModel();
    LoginModel model = new LoginModel();
    model.Username = txtUsername.Text.Trim();
    // model.Password = txtPassword.Text.Trim();
    string passwordSalt = string.Empty;
    RegistrationModel registrationModel = loginController.GetUserDetailsByUsername(model.Username);
    if (registrationModel != null) {
        passwordSalt = registrationModel.PasswordSalt;
        model.Password = StaticMethods.EncryptString(passwordSalt, txtPassword.Text.Trim());
        response = loginController.Login(model);
        if (response.Success) {
            this.Invoke(new MethodInvoker(delegate() {
                this.Hide();
                using(Dashboard dashboard = new Dashboard()) {
                    dashboard.ShowDialog();
                }
            }));
        } else {
            this.Invoke(new MethodInvoker(delegate() {
                txtUsername.ReadOnly = false;
                txtPassword.ReadOnly = false;
            }));
            btnLogin.Enabled = false;
            MessageBox.Show(response.Message, "Fail!", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
    } else {
        MessageBox.Show("Please enter valid username..", "Invalid Username!", MessageBoxButtons.OK, MessageBoxIcon.Warning);
    }
}
private void bgWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) {
    progressBar.Style = ProgressBarStyle.Blocks;
    btnLogin.Enabled = true;
}

Conclusion

 

After login, if the login process is successful, then it redirects to the homepage. Else, it shows an "Invalid Login" error message.