title: Creating login screen with WPF
body: <p>I am trying to create login screen with WPF, i have input username and password in SQL data base and connected with C# code. When i am designing in visual studio, i am not getting any error messages and everything seams fine, but when i run application and login screen shows up, i put username and password in to fields but i still get error message that information are incorrect but application still let me trough to next window.Bellow is my code in xaml and c#.</p>
  
  <pre><code>private void buttonLogin_Click(object sender, RoutedEventArgs e)
  {
      SqlConnection conn = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Denis\Documents\Data.mdf;Integrated Security=True;Connect Timeout=30");
      conn.Open();
      SqlCommand cmd = new SqlCommand("Select * from Login where Username='" + textBoxUsername + "' and Password='" + textBoxPassowrd + "'", conn);
      cmd.CommandType = CommandType.Text;
      SqlDataAdapter adapter = new SqlDataAdapter();
      adapter.SelectCommand = cmd;
      DataSet dataSet = new DataSet();
      adapter.Fill(dataSet);
  
      if (dataSet.Tables[0].Rows.Count&gt;0)
      {
          string username = dataSet.Tables[0].Rows[0]["Username"].ToString();
          Close();
      }
      else
      {
          MessageBox.Show("Invalid username or password!", "Paznja", MessageBoxButton.OK, MessageBoxImage.Error);
      }
  
      this.Hide();
      MainWindow mn = new MainWindow(); 
      mn.Show();
      this.Close();
  }
  </code></pre>