WPF login example doesn't work

L Van

15y7.1k

As I stated before I put it in debug and get a row back from my sql statement. The username gets loaded properly. When I tried to load the textblock is when I get the error.

Here is the code. My table name is Users in my database.

using

System;

using

System.Collections.Generic;

using

System.Linq;

using

System.Text;

using

System.Windows;

using

System.Windows.Controls;

using

System.Windows.Data;

using

System.Windows.Documents;

using

System.Windows.Input;

using

System.Windows.Media;

using

System.Windows.Media.Imaging;

using

System.Windows.Navigation;

using

System.Windows.Shapes;

using

System.Data;

using

System.Data.SqlClient;

using

System.Text.RegularExpressions;

namespace

{

Login_WPF///

/// Interaction logic for MainWindow.xaml

///

public partial class Login : Window

{

InitializeComponent();

}

{

errormessage.Text =

textBoxEmail.Focus();

}

{

errormessage.Text =

textBoxEmail.Select(0, textBoxEmail.Text.Length);

textBoxEmail.Focus();

}

public Login()Registration registration = new Registration();Welcome welcome = new Welcome();private void button1_Click(object sender, RoutedEventArgs e)if (textBoxEmail.Text.Length == 0)"Enter an email.";else if (!Regex.IsMatch(textBoxEmail.Text, @"^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"))"Enter a valid email.";else

{

con.Open();

cmd.CommandType =

adapter.SelectCommand = cmd;

adapter.Fill(dataSet);

{

welcome.TextBlockName.Text = username;

string email = textBoxEmail.Text;string password = passwordBox1.Password;SqlConnection con = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=Customer;Integrated Security=True;Pooling=False");SqlCommand cmd = new SqlCommand("Select * from Users where Email='" + email + "' and Password='" + password + "'", con);CommandType.Text;SqlDataAdapter adapter = new SqlDataAdapter();DataSet dataSet = new DataSet();if (dataSet.Tables[0].Rows.Count > 0)string username = dataSet.Tables[0].Rows[0]["FirstName"].ToString() + " " + dataSet.Tables[0].Rows[0]["LastName"].ToString(); //Sending value from one form to another form.

welcome.Show();

Close();

}

else

{

errormessage.Text =

}

con.Close();

}

{

registration.Show();

Close();

}

"Sorry! Please enter existing emailid/password.";private void buttonRegister_Click(object sender, RoutedEventArgs e)

19 Replies

Know the answer? Post it — somebody with the same question will find it here.

Javeed M Shaikh15y ago
Accepted answer
this is fixed, you were missing the .cs file for the welcome.xaml; I have added that and tested it works. attached is the working solution.
Javeed M Shaikh15y ago
don't worry, I am sure you should get a reply soon by a WPF expert.
L Van15y ago
I posted as another topic and I don't get responses. I have a question out there from another date that I never got a response to.
Javeed M Shaikh15y ago
Hi L Van,

Please post this is as a new question in the post so it is easier for others to find solution to any questions they are looking for as well as keep the number of replies shorter.
L Van15y ago
Thanks I appreciate that. I've got a bit to learn.
I want to take this application further so I can continue to learn. Lets say I wanted to show another window instead of the "welcome" window. So when login is clicked, instead of showing the welcome window, I wanted to show another window lets say to add customer information. So instead of showing welcome, I show "customer information" and then do the code behind to handle all the editing of the data they input, writing the new records to the database and so on? Is that how I'd do it and is that the way to do it?
Javeed M Shaikh15y ago
There is nothing dumb about that, this is the process of learning.

Happy Coding :)
L Van15y ago
I knew it was something dumb on my part. Thank you very much for all your time and help. I appreciate it.
Javeed M Shaikh15y ago
got it this time, let me check.
L Van15y ago
I went into VS 2010 folder, I found my project and opened that folder. I zipped the contents. If this isn't what you are looking for I don't know what else to give you.
Javeed M Shaikh15y ago
still the same, i do not see any other file but just .sln, please zip all the files, project and everything and send.
L Van15y ago
finally
Javeed M Shaikh15y ago
i do not see any attachment
L Van15y ago
Here is the solution
L Van15y ago
I'll try again
Javeed M Shaikh15y ago
I meant the entire solution with project and all the other files in your project which when i download on my machine i should be able to fully run it, and not just one .sln file, please delete this upload and post a new.
L Van15y ago
Here is the solution
Javeed M Shaikh15y ago
can you zip and upload your solution.
L Van15y ago
Yes I am. The code I pasted didn't paste well. Here it is.
string
username = dataSet.Tables[0].Rows[0]["FirstName"].ToString() + " " + dataSet.Tables[0].Rows[0]["LastName"].ToString();
Javeed M Shaikh15y ago
Hi L Van,

I see you have posted your code here, i see that you have not declared username variable. You are trying to assign a variable to the textblock which is not declared and assigned a value.

you should do this:

if (dataSet.Tables[0].Rows.Count > 0)
{
string username = dataSet.Tables[0].Rows[0]["FirstName"].ToString() + " " + dataSet.Tables[0].Rows[0]["FirstName"].ToString() ;
welcome.TextBlockName.Text = username;
...
...
// other code
}