在 c# windows 申请表中登录仪表板后如何获取用户名

Question

In my C# windows application I want to show the username in the dashboard window after user login.

Thanks in Advance

Here it is my login code:

private void loginbt_Click(object sender, EventArgs e)
{
    try
    {
        string qry = "SELECT empid,password FROM login WHERE (empid='" + empusernametxt.Text + "'and password='" + passwordtxt.Text + "')";
        OleDbCommand cmd = new OleDbCommand(qry, dbc.cn);
        OleDbDataReader dr = cmd.ExecuteReader();
        if (dr.Read())
        {
            dbc.cn.Close();
            MessageBox.Show("Login Successfully","Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
            EmployeeDashboard emp = new EmployeeDashboard();
            emp.Show();
         }
         else if(empusernametxt.Text=="admin" && passwordtxt.Text=="admin" )
         {
            dbc.cn.Close();
            MessageBox.Show("Login Successfully","Success",MessageBoxButtons.OK,MessageBoxIcon.Information);
            AdminDashborad admin = new AdminDashborad();
            admin.Show();
         }
         else
         {
            MessageBox.Show("Username or Password Incorrect","Warning",MessageBoxButtons.OK,MessageBoxIcon.Warning);
            empusernametxt.Focus();
            empusernametxt.Text.Equals("");
            passwordtxt.Text.Equals("");
         }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

Answer 1

Send your userName or userId(get userId after success login) as a parameter. You can use that for later user interaction.

Answer 2

You can define a public variable in your EmployeeDashboard class and pass user name to it

public class EmployeeDashboard{
public string username = "";

//your codes

}

and then re-write your loginbt_Click() like that:

private void loginbt_Click(object sender, EventArgs e)
{
    try
    {
        string qry = "SELECT empid,password FROM login WHERE (empid='" + empusernametxt.Text + "'and password='" + passwordtxt.Text + "')";
        OleDbCommand cmd = new OleDbCommand(qry, dbc.cn);
        OleDbDataReader dr = cmd.ExecuteReader();
        if (dr.Read())
        {
            dbc.cn.Close();
            MessageBox.Show("Login Successfully","Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
            EmployeeDashboard emp = new EmployeeDashboard()
            {
               username = empusernametxt.Text
            };
            emp.Show();
         }
         else if(empusernametxt.Text=="admin" && passwordtxt.Text=="admin" )
         {
            dbc.cn.Close();
            MessageBox.Show("Login Successfully","Success",MessageBoxButtons.OK,MessageBoxIcon.Information);
            AdminDashborad admin = new AdminDashborad();
            admin.Show();
         }
         else
         {
            MessageBox.Show("Username or Password Incorrect","Warning",MessageBoxButtons.OK,MessageBoxIcon.Warning);
            empusernametxt.Focus();
            empusernametxt.Text.Equals("");
            passwordtxt.Text.Equals("");
         }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

you can use username in your main code