How to Make a Log-in form Using Local database

Hi there,
Its very easy to create a Login Form with C# and WPF.

I just created it. You can keep Connection String in project settings. For this,
1. You need to right click on your wpf project and select Properties.
2. There you will find a tab named "Settings" next to "Services" and followed by "Reference Paths". Now Click on that - Settings.
3. Now you can add Name for your setting and You can also set type i.e., datatype and Scope for your setting. Keep Scope to User, and provide value for your setting,
i.e., your connection string "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True".
4. Save the project now.

Now talking about WPF Login project, I create a WPF window with
TextBox for Username
PasswordBox for Password
TextBlock for Error
Buttons for Login, Reset the input fields and closing the window.

And I created a seperate class file named "Authorization.cs" to keep Login function seperate from code behind window file. In Autorization class, I created a function called Login(string Username, string Password), which needs two string parameters for passing username and password.

And I paste the code for the project,

For MainWindow.xaml

<window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d" x:Class="LoginExample.MainWindow"
        Title="User Login" Height="212" Width="400">
    <grid>
    	<groupbox x:name="GroupBoxLogin" header="Login Form" margin="8" xmlns:x="#unknown">
    		<grid>
    			<label x:name="LabelUserName" content="User Name:" horizontalalignment="Left" verticalalignment="Top" margin="8,8,0,0" width="115.993" />
    			<label x:name="LabelPassword" content="Password:" horizontalalignment="Left" verticalalignment="Top" margin="8,37.96,0,0" width="115.993" />
    			<textbox x:name="TextUserName" textwrapping="Wrap" verticalalignment="Top" margin="123.993,8,8,0" height="25.96" />
    			<passwordbox x:name="PasswordUserPwd" verticalalignment="Top" margin="123.993,37.96,8,0" height="25.96" />
    			<textblock x:name="TextError" textwrapping="Wrap" verticalalignment="Top" margin="123.993,67.92,8,0" height="21.96" foreground="Red" fontstyle="Italic" />
    			<button x:name="ButtonLogIn" content="Log In" horizontalalignment="Left" width="100" margin="8.993,93.88,0,0" verticalalignment="Top" height="30" click="Button_Click" />
    			<button x:name="ButtonReset" content="Reset" margin="0,93.88,0,0" height="30" verticalalignment="Top" click="Button_Click" width="100" horizontalalignment="Center" />
    			<button x:name="ButtonCancel" content="Cancel" margin="0,93.88,8,0" height="30" verticalalignment="Top" click="Button_Click" horizontalalignment="Right" width="100" />
    		</grid>
    	</groupbox>
    </grid>
</window>

For MainWindow.xaml.cs

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;

namespace LoginExample
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
        {
            try
            {
                if (sender == ButtonLogIn)
                {
                    if (Authorization.Login(TextUserName.Text.Trim(), PasswordUserPwd.Password.Trim()) == true)
                    {
                        MessageBox.Show("Login Successfull");
                        // You can now open your main form here
                    }
                    else
                    {
                        TextError.Text = "* Username or Password is incorrect.";
                    }
                }

                if (sender == ButtonReset)
                {
                    TextUserName.Text = "";
                    PasswordUserPwd.Password = "";
                    TextError.Text = "";
                }

                if (sender == ButtonCancel)
                {
                    this.Close();
                }
            }
            catch (Exception Ex)
            {
                MessageBox.Show("Exception: " + Ex.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }
    }
}

For Class Autorization.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace LoginExample
{
    public static class Authorization
    {
        public static bool Login(string UserName, string Password)
        {
            DataTable _DataTable = new DataTable();
            SqlConnection _SqlConnection = new SqlConnection(Properties.Settings.Default.ConnectionString);
            _SqlConnection.Open();

            using (SqlDataAdapter _SqlDataAdapter = new SqlDataAdapter("SELECT * FROM Login WHERE UserId#='" + UserName + "' AND Password='" + Password + "'", _SqlConnection))
            {
                _SqlDataAdapter.Fill(_DataTable);
            }

            if (_DataTable.Rows.Count != 0)
                return true;
            else
                return false;
        }
    }
}

Here MainWindow refers your Login Window.