How can login in windows application?

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Hi,

I am creating login form which has two text boxes for username and password correspondingly and two buttons which is save and login.Now i can store username and password in database by pressing save button.Now i need code to login.When i press login button,it should check the username,password is correct or not.If it is correct, it should work.Kindly send me the coding.

Thanks & Regards,

Viswanathan.M

Posted 5-Jul-11 20:27pm

Viswanthan.M.

Updated 6-Jul-11 9:04am

#realJSOP

v3

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[no name] 6-Jul-11 2:29am

you are asking or telling us.

Viswanthan.M. 6-Jul-11 2:30am

asking...

5 solutions

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SanjeevSingh · Answer 1 · 2011-07-05T20:34:00

Solution 1

hello Viswanthan,

you have created connection to insert the data. then use that connection to retrieve the data from ur DB store in Data table and check against ur username and password. if it matches then show the next window else show the message that username password is wrong.

this all you can do on login button click event

thanks
sanjeev

Posted 5-Jul-11 20:34pm

SanjeevSingh

Comments

Viswanthan.M. 6-Jul-11 2:36am

Hi Mr.Sanjeev,

I know the concept... I have some codings,but it ll not work. So kindly send me the coding please.

walterhevedeich 6-Jul-11 2:37am

Update your question and post your code, including the error details and line where it errored. That way, we may be able to help you to pinpoint what the issue is.

[no name] 6-Jul-11 2:37am

give me ur insert button code i'll convert it for login

Viswanthan.M. 6-Jul-11 2:41am

private void btnSave_Click(object sender, EventArgs e)
{
if ((txtUserName.Text != "") & (txtPassword.Text != ""))
{
DialogResult dr = MessageBox.Show("Do you Want to be a User?", "Information", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (dr==DialogResult.Yes)
{
con.Open();
SqlCommand cmd = new SqlCommand("insert into login values ('" + txtUserName.Text + "','" + txtPassword.Text + "')", con);
cmd.ExecuteNonQuery();
con.Close();
}
}
else
{
MessageBox.Show("Give Full Details","Warning",MessageBoxButtons.OK,MessageBoxIcon.Warning);
}
}
......
this is my insert button code.

Viswanthan.M. 6-Jul-11 2:49am

HI sanjeev,

Can you help me?

[no name] 6-Jul-11 3:47am

ok follow these steps for btnLogin_Click
1: declare datatable dt;
2 take a string str= "select User,password from login where user='"+txtUserName.text+"'" and password='"+txtPassword.text+"';
3: take a sqladapter sqladapter sda
fill the table with sda.fill
and now check with if condition

2irfanshaikh · Answer 2 · 2011-07-05T20:35:00

Solution 2

Please check the below links:

A simple Windows Forms Login Control component[^]

Generic Login Control[^]

Posted 5-Jul-11 20:35pm

2irfanshaikh

Abhinav S · Answer 3 · 2011-07-05T20:36:00

Solution 3

Depends on where you are storing your username and password (database, file etc).

You need to write your logic so that it checks against this store and then login only if the password matches.

Posted 5-Jul-11 20:36pm

Abhinav S

SREENATH GANGA · Answer 4 · 2011-07-06T07:22:00

Here is a simple code

Try to call all data from the database where username=? and password=?
If the dataset returned is not null make him login else stop there with an error message

C#

 private void button1_Click(object sender, EventArgs e)
{
    try
    {
        if (txtUsername.Text.Trim() == null || txtUsername.Text.Trim() == "")
        {
            MessageBox.Show("Enter an valid username");
            txtUsername.Focus();
            txtUsername.Text = "";
        }
        else if (txtPassword.Text.Trim() == null || txtPassword.Text.Trim() == "")
        {
            MessageBox.Show("Enter an valid password");
            txtPassword.Focus();
            txtPassword.Text = "";
        }
        else
        {
            OleDbConnection oleDbConnection1 = new System.Data.OleDb.OleDbConnection(connString);
            oleDbConnection1.Open();
            OleDbCommand oleDbCommand1 = new System.Data.OleDb.OleDbCommand("select *  from masterusertable where userid='" + txtUsername.Text + "' AND passsword='" + txtPassword.Text + "'", oleDbConnection1);
            oleDbCommand1.CommandType = CommandType.Text;
            try
            {
                OleDbDataReader data = oleDbCommand1.ExecuteReader();
                if (data.Read() == true)
                {                         
                    this.Hide();
                    MainMenuForm mainmenuform = new MainMenuForm();
                    mainmenuform.Show();
                }
                else
                {
                    MessageBox.Show("Enter an valid username or password");
                    txtUsername.Text = "";
                }
            }
            catch (Exception exp)
            {
                MessageBox.Show("Exception at Database close any Access Database program and restart");
                Console.WriteLine("Error", exp);
            }           
        }
    }
    catch (Exception eps)
    {
        Console.WriteLine("Error",eps);           
    }
}

#realJSOP · Answer 5 · 2011-07-06T09:09:00

A login form should NOT be used to *save* user credentials. Instead, you should use a registration form. So, take the "save" button off your login form. There should be two text boxes (user ID and password), and two buttons (OK and CANCEL).

If the user can't be authenticated, he should be presented with either the appropriate error message, or a chance to register (using a different form, of course). Once registered, he should be re-prompted to login before being granted access to the application.