WPFHelperForAlex 1.0.3

//authorizatiomwindow.xaml
<window x: class = "wpfapp1.authorizationwindow"
       xmlns = "https://schemas.microsoft.com/winfx/2006/xaml/presentation"
       xmlns: x = "https://schemas.microsoft.com/winfx/2006/xaml"
       xmlns: d = "https://schemas.microsoft.com/expression/blend/2008"
       xmlns: mc = "http://schemas.openxmlformats.org/markup-compatibility/2006"
       xmlns: local = "clr-namespace:wpfapp1"
       mc: ignorable = "d"
       title = "authorizationwindow" height = "450" width = "800" >
   <grid >
       <label content = "авторизация" horizontalalignment = "center" margin = "0,38,0,0" verticalalignment = "top" / >
       <textbox x: name = "logbox" horizontalalignment = "center" margin = "0,217,0,0" textwrapping = "wrap" text = "login" verticalalignment = "top" width = "120" / >
       <textbox x: name = "pasbox" horizontalalignment = "center" margin = "0,251,0,0" textwrapping = "wrap" text = "password" verticalalignment = "top" width = "120" textchanged = "pasbox_textchanged" / >
       <button x: name = "loginbutton" content = "войти" horizontalalignment = "center" margin = "0,290,0,0" verticalalignment = "top" click = "loginbutton_click" / >
       <button x: name = "guestbutton" content = "войти как гость" horizontalalignment = "center" margin = "0,385,0,0" verticalalignment = "top" click = "button_click" / >

   < / grid >
< / window >



//authorizationwindow.xaml.cs
using microsoft.entityframeworkcore;
using microsoft.entityframeworkcore.storage;
using system;
using system.collections.generic;
using system.linq;
using system.text;
using system.threading.tasks;
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.shapes;
using wpfapp1.models;

namespace wpfapp1
{
   /// <summary>
   /// логика взаимодействия для authorizationwindow.xaml
   /// </summary>
   public partial class authorizationwindow : window
   {
       wpfcontext db = wpfcontext.getinstance();
       public authorizationwindow()
       {
           initializecomponent();
       }

       private void pasbox_textchanged(object sender, textchangedeventargs e)
       {

       }

       private void loginbutton_click(object sender, routedeventargs e)
       {
           if (!string.isnullorempty(logbox.text) && !string.isnullorempty(pasbox.text))
           {
               var user = db.users.include(u = > u.idrolenavigation).firstordefault(x = > x.login == logbox.text && x.password == pasbox.text);
               if (user != null)
               {
                   mainwindow mainwindow = new mainwindow(user);
                   mainwindow.show();

                   this.close();
               }
               else
               {
                   messagebox.show("неверный логин или пароль");
               }
           }
           else
           {
               messagebox.show("заполните поля login и password");
           }
       }

       private void button_click(object sender, routedeventargs e)
       {
           mainwindow mainwindow = new mainwindow(null);
           mainwindow.show();

           this.close();
       }
   }
}