void addImageFromStream(byte[] data)
        {
            if (data == null) return;
            using (var ms = new MemoryStream(data))
            {
                var image = Image.FromStream(ms);
                _worksheet.Row(_row).Height = (image.Height + 1).Pixel2RowHeight();
                _worksheet.Column(_col).Width = _worksheet.Pixel2ColumnWidth(image.Width + 1);
                var picture = _worksheet.Drawings.AddPicture("pic" + _row + _col, image);
                picture.From.Column = _col - 1;
                picture.From.Row = _row - 1;
                picture.From.ColumnOff = 2.Pixel2Mtu();
                picture.From.RowOff = 2.Pixel2Mtu();
                picture.SetSize(image.Width, image.Height);
            }
        }

namespace DNT.IDP
{
    public static class Config
    {
        public static IEnumerable<Client> GetClients()
        {
            return new List<Client>
            {
                new Client
                {
                    ClientName = "Image Gallery",
                    // IdentityTokenLifetime = ... // defaults to 300 seconds / 5 minutes
                    // AuthorizationCodeLifetime = ... // defaults to 300 seconds / 5 minutes
                    // AccessTokenLifetime = ... // defaults to 3600 seconds / 1 hour
                }
             };
        }
    }
}

namespace DNT.IDP
{
    public static class Config
    {
        public static IEnumerable<Client> GetClients()
        {
            return new List<Client>
            {
                new Client
                {
                    ClientName = "Image Gallery",
                    // IdentityTokenLifetime = ... // defaults to 300 seconds / 5 minutes
                    // AuthorizationCodeLifetime = ... // defaults to 300 seconds / 5 minutes
                    // AccessTokenLifetime = ... // defaults to 3600 seconds / 1 hour
                    AllowOfflineAccess = true,
                    // AbsoluteRefreshTokenLifetime = ... // Defaults to 2592000 seconds / 30 days
                    // RefreshTokenExpiration = TokenExpiration.Sliding
                    UpdateAccessTokenClaimsOnRefresh = true,
                    // ...
                }
             };
        }
    }
}

options.Scope.Add("offline_access");

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using IdentityModel.Client;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Protocols.OpenIdConnect;

namespace ImageGallery.MvcClient.Services
{
    public interface IImageGalleryHttpClient
    {
        Task<HttpClient> GetHttpClientAsync();
    }

    /// <summary>
    /// A typed HttpClient.
    /// </summary>
    public class ImageGalleryHttpClient : IImageGalleryHttpClient
    {
        private readonly HttpClient _httpClient;
        private readonly IConfiguration _configuration;
        private readonly IHttpContextAccessor _httpContextAccessor;
        private readonly ILogger<ImageGalleryHttpClient> _logger;

        public ImageGalleryHttpClient(
            HttpClient httpClient,
            IConfiguration configuration,
            IHttpContextAccessor httpContextAccessor,
            ILogger<ImageGalleryHttpClient> logger)
        {
            _httpClient = httpClient;
            _configuration = configuration;
            _httpContextAccessor = httpContextAccessor;
            _logger = logger;
        }

        public async Task<HttpClient> GetHttpClientAsync()
        {
            var accessToken = string.Empty;

            var currentContext = _httpContextAccessor.HttpContext;
            var expires_at = await currentContext.GetTokenAsync("expires_at");
            if (string.IsNullOrWhiteSpace(expires_at)
                || ((DateTime.Parse(expires_at).AddSeconds(-60)).ToUniversalTime() < DateTime.UtcNow))
            {
                accessToken = await RenewTokens();
            }
            else
            {
                accessToken = await currentContext.GetTokenAsync(OpenIdConnectParameterNames.AccessToken);
            }

            if (!string.IsNullOrWhiteSpace(accessToken))
            {
                _logger.LogInformation($"Using Access Token: {accessToken}");
                _httpClient.SetBearerToken(accessToken);
            }

            _httpClient.BaseAddress = new Uri(_configuration["WebApiBaseAddress"]);
            _httpClient.DefaultRequestHeaders.Accept.Clear();
            _httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

            return _httpClient;
        }

        private async Task<string> RenewTokens()
        {
            // get the current HttpContext to access the tokens
            var currentContext = _httpContextAccessor.HttpContext;

            // get the metadata
            var discoveryClient = new DiscoveryClient(_configuration["IDPBaseAddress"]);
            var metaDataResponse = await discoveryClient.GetAsync();

            // create a new token client to get new tokens
            var tokenClient = new TokenClient(
                metaDataResponse.TokenEndpoint,
                _configuration["ClientId"],
                _configuration["ClientSecret"]);

            // get the saved refresh token
            var currentRefreshToken = await currentContext.GetTokenAsync(OpenIdConnectParameterNames.RefreshToken);

            // refresh the tokens
            var tokenResult = await tokenClient.RequestRefreshTokenAsync(currentRefreshToken);
            if (tokenResult.IsError)
            {
                throw new Exception("Problem encountered while refreshing tokens.", tokenResult.Exception);
            }

            // update the tokens & expiration value
            var updatedTokens = new List<AuthenticationToken>();
            updatedTokens.Add(new AuthenticationToken
            {
                Name = OpenIdConnectParameterNames.IdToken,
                Value = tokenResult.IdentityToken
            });
            updatedTokens.Add(new AuthenticationToken
            {
                Name = OpenIdConnectParameterNames.AccessToken,
                Value = tokenResult.AccessToken
            });
            updatedTokens.Add(new AuthenticationToken
            {
                Name = OpenIdConnectParameterNames.RefreshToken,
                Value = tokenResult.RefreshToken
            });

            var expiresAt = DateTime.UtcNow + TimeSpan.FromSeconds(tokenResult.ExpiresIn);
            updatedTokens.Add(new AuthenticationToken
            {
                Name = "expires_at",
                Value = expiresAt.ToString("o", CultureInfo.InvariantCulture)
            });

            // get authenticate result, containing the current principal & properties
            var currentAuthenticateResult = await currentContext.AuthenticateAsync("Cookies");

            // store the updated tokens
            currentAuthenticateResult.Properties.StoreTokens(updatedTokens);

            // sign in
            await currentContext.SignInAsync("Cookies",
             currentAuthenticateResult.Principal, currentAuthenticateResult.Properties);

            // return the new access token
            return tokenResult.AccessToken;
        }
    }
}

namespace DNT.IDP
{
    public static class Config
    {
        public static IEnumerable<Client> GetClients()
        {
            return new List<Client>
            {
                new Client
                {
                    ClientName = "Image Gallery",
// ...
                    AccessTokenType = AccessTokenType.Reference
                }
             };
        }
    }
}

namespace DNT.IDP
{
    public static class Config
    {
        // api-related resources (scopes)
        public static IEnumerable<ApiResource> GetApiResources()
        {
            return new List<ApiResource>
            {
                new ApiResource(
                    name: "imagegalleryapi",
                    displayName: "Image Gallery API",
                    claimTypes: new List<string> {"role" })
                {
                  ApiSecrets = { new Secret("apisecret".Sha256()) }
                }
            };
        }

namespace ImageGallery.WebApi.WebApp
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddAuthentication(defaultScheme: IdentityServerAuthenticationDefaults.AuthenticationScheme)
               .AddIdentityServerAuthentication(options =>
               {
                   options.Authority = Configuration["IDPBaseAddress"];
                   options.ApiName = "imagegalleryapi";
                   options.ApiSecret = "apisecret";
               });

namespace ImageGallery.MvcClient.WebApp.Controllers
{
    [Authorize]
    public class GalleryController : Controller
    {
        public async Task Logout()
        {
            await revokeTokens();
            // Clears the  local cookie ("Cookies" must match the name of the scheme)
            await HttpContext.SignOutAsync("Cookies");
            await HttpContext.SignOutAsync("oidc");
        }

        private async Task revokeTokens()
        {
            var discoveryClient = new DiscoveryClient(_configuration["IDPBaseAddress"]);
            var metaDataResponse = await discoveryClient.GetAsync();
            var tokenRevocationClient = new TokenRevocationClient(
                metaDataResponse.RevocationEndpoint,
                _configuration["ClientId"],
                _configuration["ClientSecret"]
            );

            var accessToken = await HttpContext.GetTokenAsync(OpenIdConnectParameterNames.AccessToken);
            if (!string.IsNullOrWhiteSpace(accessToken))
            {
                var response = await tokenRevocationClient.RevokeAccessTokenAsync(accessToken);
                if (response.IsError)
                {
                    throw new Exception("Problem accessing the TokenRevocation endpoint.", response.Exception);
                }
            }

            var refreshToken = await HttpContext.GetTokenAsync(OpenIdConnectParameterNames.RefreshToken);
            if (!string.IsNullOrWhiteSpace(refreshToken))
            {
                var response = await tokenRevocationClient.RevokeRefreshTokenAsync(refreshToken);
                if (response.IsError)
                {
                    throw new Exception("Problem accessing the TokenRevocation endpoint.", response.Exception);
                }
            }
        }

var facilities = context.Facilities.ToList();

var facilities = context.Facilities.Select(x =>
                    new
                    {
                        x.Name,
                        x.MemberCost
                    }).ToList();

var facilities = context.Facilities.Where(x => x.MemberCost > 0).ToList();

var facilities = context.Facilities.Where(x => x.MemberCost > 0
                                                            && x.MemberCost < (x.MonthlyMaintenance / 50))
                                                    .Select(x =>
                                                        new
                                                        {
                                                            x.FacId,
                                                            x.Name,
                                                            x.MemberCost,
                                                            x.MonthlyMaintenance
                                                        }).ToList();

var facilities = context.Facilities.Where(x => x.Name.Contains("Tennis")).ToList();

int[] ids = { 1, 5 };
var facilities = context.Facilities.Where(x => ids.Contains(x.FacId)).ToList();

var facilities = context.Facilities
                        .Select(x =>
                                    new
                                    {
                                        x.Name,
                                        Cost = x.MonthlyMaintenance > 100 ? "expensive" : "cheap"
                                    }).ToList();

var date = new DateTime(2012, 09, 01);
var members = context.Members.Where(x => x.JoinDate >= date)
                                            .Select(x =>
                                                        new
                                                        {
                                                            x.MemId,
                                                            x.Surname,
                                                            x.FirstName,
                                                            x.JoinDate
                                                        }).ToList();

var members = context.Members.OrderBy(x => x.Surname)
                                            .Select(x =>
                                                        new
                                                        {
                                                            x.Surname
                                                        })
                                            .Distinct()
                                            .Take(10)
                                            .ToList();

var names = context.Members.Select(m => m.Surname).ToList()
                            .Union(context.Facilities.Select(f => f.Name).ToList()) // For now we have to use `.ToList()` here
                            .ToList();

SELECT surname
FROM members
UNION
SELECT name
FROM facilities;

var latest = context.Members.Max(x => x.JoinDate);

var latest2 = context.Members.Select(m => m.JoinDate).DefaultIfEmpty().Max();

SELECT MAX([m].[JoinDate])
FROM   (SELECT NULL AS [empty]) AS [empty]
       LEFT OUTER JOIN
       [Members] AS [m]
       ON 1 = 1;

var latest3 = context.Members.Max(m => (DateTime?)m.JoinDate) ?? DateTime.Now;

var latest4 = context.Members.OrderByDescending(m => m.JoinDate).Select(m => m.JoinDate).FirstOrDefault();

var lastMember = context.Members.OrderByDescending(m => m.JoinDate)
                            .Select(x => new { x.FirstName, x.Surname, x.JoinDate })
                            .FirstOrDefault();

var members = context.Members.Select(x => new { x.FirstName, x.Surname, x.JoinDate })
                                    .Where(x => x.JoinDate == context.Members.Max(x => x.JoinDate))
                                    .ToList();

 >ng g c Dashboard/CallProtectedApi

import { CallProtectedApiComponent } from "./call-protected-api/call-protected-api.component";

const routes: Routes = [
  {
    path: "callProtectedApi",
    component: CallProtectedApiComponent,
    data: {
      permission: {
        permittedRoles: ["Admin", "User"],
        deniedRoles: null
      } as AuthGuardPermission
    },
    canActivate: [AuthGuard]
  }
];

<li *ngIf="isLoggedIn" routerLinkActive="active">
        <a [routerLink]="['/callProtectedApi']">‍‍Call Protected Api</a>
</li>

import { Component, OnInit } from "@angular/core";
import { AuthService } from "../../core/services/auth.service";

@Component({
  selector: "app-call-protected-api",
  templateUrl: "./call-protected-api.component.html",
  styleUrls: ["./call-protected-api.component.css"]
})
export class CallProtectedApiComponent implements OnInit {

  isAdmin = false;
  isUser = false;
  result: any;

  constructor(private authService: AuthService) { }

  ngOnInit() {
    this.isAdmin = this.authService.isAuthUserInRole("Admin");
    this.isUser = this.authService.isAuthUserInRole("User");
  }

  callMyProtectedAdminApiController() {
  }

  callMyProtectedApiController() {
  }
}

<button *ngIf="isAdmin" (click)="callMyProtectedAdminApiController()">
  Call Protected Admin API [Authorize(Roles = "Admin")]
</button>

<button *ngIf="isAdmin || isUser" (click)="callMyProtectedApiController()">
  Call Protected API ([Authorize])
</button>

<div *ngIf="result">
  <pre>{{result | json}}</pre>
</div>

  getBearerAuthHeader(): HttpHeaders {
    return new HttpHeaders({
      "Content-Type": "application/json",
      "Authorization": `Bearer ${this.getRawAuthToken(AuthTokenType.AccessToken)}`
    });
  }

import { Injectable } from "@angular/core";
import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from "@angular/common/http";
import { Observable } from "rxjs/Observable";

import { AuthService, AuthTokenType } from "./auth.service";

@Injectable()
export class AuthInterceptor implements HttpInterceptor {

  constructor(private authService: AuthService) { }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

    const accessToken = this.authService.getRawAuthToken(AuthTokenType.AccessToken);
    if (accessToken) {
      request = request.clone({
        headers: request.headers.set("Authorization", `Bearer ${accessToken}`)
      });
    }

    return next.handle(request);
  }
}

import { HTTP_INTERCEPTORS } from "@angular/common/http";

import { AuthInterceptor } from "./services/auth.interceptor";

@NgModule({
  providers: [
    {
      provide: HTTP_INTERCEPTORS,
      useClass: AuthInterceptor,
      multi: true
    }
  ]
})
export class CoreModule {}

compiler.js:19514 Uncaught Error: Provider parse errors:
Cannot instantiate cyclic dependency! InjectionToken_HTTP_INTERCEPTORS ("[ERROR ->]"): in NgModule AppModule in ./AppModule@-1:-1

import { Injector } from "@angular/core";

  constructor(private injector: Injector) { }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const authService = this.injector.get(AuthService);

@Injectable()
export class AuthInterceptor implements HttpInterceptor {

  constructor(private injector: Injector) { }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const authService = this.injector.get(AuthService);
    const accessToken = authService.getRawAuthToken(AuthTokenType.AccessToken);
    if (accessToken) {
      request = request.clone({
        headers: request.headers.set("Authorization", `Bearer ${accessToken}`)
      });
    }

    return next.handle(request);
  }
}

  constructor(
    private authService: AuthService,
    private httpClient: HttpClient,
    @Inject(APP_CONFIG) private appConfig: IAppConfig,
  ) { }

  callMyProtectedAdminApiController() {
    this.httpClient
      .get(`${this.appConfig.apiEndpoint}/MyProtectedAdminApi`)
      .map(response => response || {})
      .catch((error: HttpErrorResponse) => Observable.throw(error))
      .subscribe(result => {
        this.result = result;
      });
  }

  callMyProtectedApiController() {
    this.httpClient
      .get(`${this.appConfig.apiEndpoint}/MyProtectedApi`)
      .map(response => response || {})
      .catch((error: HttpErrorResponse) => Observable.throw(error))
      .subscribe(result => {
        this.result = result;
      });
  }

    return next.handle(request)
      .catch((error: any, caught: Observable<HttpEvent<any>>) => {
        if (error.status === 401 || error.status === 403) {
          this.router.navigate(["/accessDenied"]);
        }
        return Observable.throw(error);
      });

@Injectable()
export class AuthInterceptor implements HttpInterceptor {

  constructor(
    private injector: Injector,
    private router: Router) { }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const authService = this.injector.get(AuthService);
    const accessToken = authService.getRawAuthToken(AuthTokenType.AccessToken);
    if (accessToken) {
      request = request.clone({
        headers: request.headers.set("Authorization", `Bearer ${accessToken}`)
      });
      return next.handle(request)
        .catch((error: any, caught: Observable<HttpEvent<any>>) => {
          if (error.status === 401 || error.status === 403) {
            this.router.navigate(["/accessDenied"]);
          }
          return Observable.throw(error);
        });
    } else {
      // login page
      return next.handle(request);
    }
  }
}

using ASPNETCore2JwtAuthentication.Services;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Cors;
using Microsoft.AspNetCore.Mvc;

namespace ASPNETCore2JwtAuthentication.WebApp.Controllers
{
    [Route("api/[controller]")]
    [EnableCors("CorsPolicy")]
    [Authorize(Policy = CustomRoles.Editor)]
    public class MyProtectedEditorsApiController : Controller
    {
        public IActionResult Get()
        {
            return Ok(new
            {
                Id = 1,
                Title = "Hello from My Protected Editors Controller! [Authorize(Policy = CustomRoles.Editor)]",
                Username = this.User.Identity.Name
            });
        }
    }
}

  callMyProtectedEditorsApiController() {
    this.httpClient
      .get(`${this.appConfig.apiEndpoint}/MyProtectedEditorsApi`)
      .map(response => response || {})
      .catch((error: HttpErrorResponse) => Observable.throw(error))
      .subscribe(result => {
        this.result = result;
      });
  }

var sequence = new[] { 12, 3, -4, 7 }.ToObservable();
var runningSum = sequence.Scan((accumulator, value) =>
{
    Console.WriteLine("accumulator {0}", accumulator);
    Console.WriteLine("value {0}", value);
    return accumulator + value;
});
runningSum.Subscribe(result => Console.WriteLine("result {0}\n", result));

result 12

accumulator 12
value 3
result 15

accumulator 15
value -4
result 11

accumulator 11
value 7
result 18

 var runningSum = sequence.Scan(seed: 10, accumulator: (accumulator, value) =>

var sequence = Enumerable.Range(1, 200)
                 .ToObservable()
                 .Buffer(count: 10);

sequence.Subscribe(onNext: numbers =>
{
   Console.WriteLine(numbers.Sum());
});

 var sequence = Enumerable.Range(1, 200)
                   .ToObservable()
                   .Buffer(timeSpan: TimeSpan.FromSeconds(2));

 var sequence = Enumerable.Range(1, 200)
                           .ToObservable()
                           .Window(timeSpan: TimeSpan.FromSeconds(2));

sequence.Subscribe(onNext: numbers =>
{
       numbers.Subscribe(onNext: number => Console.WriteLine(number));
});

 var sequence = Enumerable.Range(1, 200)
                          .ToObservable()
                          .Window(10);

sequence.Subscribe(onNext: numbers =>
{
     numbers.Sum().Subscribe(onNext: number => Console.WriteLine(number));
});

statusBarColor
textColorPrimary
colorAccent
ColorPrimary
WindowBackground

[Activity(Theme = "@style/NameThem")]

 [Activity(Theme = "@style/NameThem")]

<?xml version="1.0" encoding="utf-8" ?>
<resources>
  <style name="MainTheme" parent="Theme.AppCompat.Light.DarkActionBar">
     <item name="windowNoTitle">true</item>
     <item name="windowActionBar">false</item>
  </style>
</resources>

 <menu xmlns:android="http://schemas.android.com/apk/res/android">

 <?xml version="1.0" encoding="utf-8" ?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
  <group android:checkableBehavior="single">
     <item android:id="@+id/menuItemHome" android:title="صفحه اصلی"></item>
     <item android:id="@+id/menuItemInsertProduct" android:title="ورود کالا جدید" ></item>
     <item android:id="@+id/menuItemListProduct" android:title="مشاهده کالاها"></item>
     <item android:id="@+id/menuItemExit"  android:title="خروج"></item>
  </group>
</menu>

<android.support.v7.widget.Toolbar
  android:layout_width="match_parent"
  android:id="@+id/toolbar1"
  android:background="#33B86C"
  android:minHeight="?android:attr/actionBarSize"
  android:layout_height="wrap_content">
</android.support.v7.widget.Toolbar>

<?xml version="1.0" encoding="utf-8" ?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
  <group android:checkableBehavior="single">
    <item android:id="@+id/menuItemHome" android:title="صفحه اصلی"></item>
    <item android:id="@+id/menuItemInsertProduct" android:title="ورود کالا جدید" ></item>
    <item android:id="@+id/menuItemListProduct" android:title="مشاهده کالاها"></item>
    <item android:id="@+id/menuItemExit"  android:title="خروج"></item>
  </group>
</menu>

 xmlns:app="http://schemas.android.com/apk/res-auto"

 SupportActionBar.SetDisplayShowTitleEnabled(false);

        var navigationview = this.FindViewById<NavigationView>(Resource.Id.navigationView1);
        navigationview.NavigationItemSelected += Navigationview_NavigationItemSelected;
        private void Navigationview_NavigationItemSelected(object sender, NavigationView.NavigationItemSelectedEventArgs e)
        {
            Intent intent = null;
            switch (e.MenuItem.ItemId)
            {
                case Resource.Id.menuItemHome:

                    break;
                case Resource.Id.menuItemExit:
                    Finish();
                    break;
                case Resource.Id.menuItemInsertProduct:

                    break;
                case Resource.Id.menuItemListProduct:

                    break;
            }
        }

<?xml version="1.0" encoding="utf-8" ?>
<merge xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/toolbarlayout">
    <android.support.v7.widget.Toolbar android:layout_width="match_parent" android:id="@+id/toolbar1" android:background="#33B86C" android:minHeight="?android:attr/actionBarSize" android:layout_height="wrap_content">
        <ImageButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/imageButton1" android:background="@drawable/mainmenu" android:layout_gravity="end" />
    </android.support.v7.widget.Toolbar>
    <android.support.v4.widget.DrawerLayout android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/drawerLayout1" android:fitsSystemWindows="true">
        <android.support.design.widget.NavigationView android:minWidth="25px" android:minHeight="25px" android:layout_width="200dp" android:layout_height="match_parent" android:layout_gravity="end" app:menu="@menu/menu" android:id="@+id/navigationView1" android:fitsSystemWindows="true" />
    </android.support.v4.widget.DrawerLayout>
</merge>

        private void Navigationview_NavigationItemSelected(object sender, NavigationView.NavigationItemSelectedEventArgs e)
        {
            Intent intent = null;
            switch (e.MenuItem.ItemId)
            {
                case Resource.Id.menuItemHome:
                    intent = new Intent(this, typeof(MainActivity));
                    break;
                case Resource.Id.menuItemExit:
                    Finish();
                    break;
                case Resource.Id.menuItemInsertProduct:
                    intent = new Intent(this, typeof(InsertActivity));
                    break;
                case Resource.Id.menuItemListProduct:
                    intent = new Intent(this, typeof(ListProductsActivity));
                    break;
            }
            if (intent != null) { }
        }

    public class BaseAcitivity : AppCompatActivity
    {
        protected void InitieToolbar()
        {
            var toolbar = this.FindViewById<widgetV7.Toolbar>(Resource.Id.toolbar1);
            this.SetSupportActionBar(toolbar);
            //SupportActionBar.SetDisplayShowTitleEnabled(false);
            var imagebutton = toolbar.FindViewById<ImageButton>(Resource.Id.imageButton1);
            imagebutton.Click += Imagebutton_Click;
            var navigationview = this.FindViewById<NavigationView>(Resource.Id.navigationView1);
            navigationview.NavigationItemSelected += Navigationview_NavigationItemSelected;
        }

        private void Navigationview_NavigationItemSelected(object sender, NavigationView.NavigationItemSelectedEventArgs e)
        {
            Intent intent = null;
            switch (e.MenuItem.ItemId)
            {
                case Resource.Id.menuItemHome:
                    intent = new Intent(this, typeof(MainActivity));
                    break;
                case Resource.Id.menuItemExit:
                    Finish();
                    break;
                case Resource.Id.menuItemInsertProduct:
                    intent = new Intent(this, typeof(InsertActivity));
                    break;
                case Resource.Id.menuItemListProduct:
                    intent = new Intent(this, typeof(ListProductsActivity));
                    break;
            }
            if (intent != null)
                StartActivity(intent);
        }

        private void Imagebutton_Click(object sender, EventArgs e)
        {
            var drawerlayout = this.FindViewById<DrawerLayout>(Resource.Id.drawerLayout1);
            if (drawerlayout.IsDrawerOpen(Android.Support.V4.View.GravityCompat.End) == false)
            {
                drawerlayout.OpenDrawer(Android.Support.V4.View.GravityCompat.End);
            }
            else
            {
                drawerlayout.CloseDrawer(Android.Support.V4.View.GravityCompat.End);
            }
        }
    }

 android:theme="@style/Theme.AppCompat.Light.NoActionBar"

    public class Fragment1 : Android.Support.V4.App.Fragment
    {
        public override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
        }
        public override View OnCreateView(LayoutInflater inflater,
      ViewGroup container, Bundle savedInstanceState)
        {
            return inflater.Inflate(Resource.Layout.FragmentLayout1, container, false);
        }
    }

 var tablayout = FindViewById<Android.Support.Design.Widget.TabLayout>(Resource.Id.tabLayout1);
var viewpager = FindViewById<ViewPager>(Resource.Id.viewPager1);
tablayout.SetupWithViewPager(viewpager);

    class TabFragmentAdapter : FragmentPagerAdapter
    {
        public TabFragmentAdapter(FragmentManager fm) : base(fm)
        {
        }
        public override int Count => 3;
        public override Fragment GetItem(int position)
        {
            switch (position)
            {
                case 0: return new Fragment1();
                case 1: return new Fragment2();
                case 2: return new Fragment3();
                default: return new Fragment1();
            }
        }


        //int f1() { return 100; }
        //int f1 => 100;
    }

 viewpager.Adapter = new TabFragmentAdapter(this.SupportFragmentManager);

 tablayout.GetTabAt(0).SetIcon(Resource.Drawable.iconCall);

 View iconlayout1 = LayoutInflater.Inflate(Resource.Layout.custom_TabIconLayout, null);
var txt = iconlayout1.FindViewById<TextView>(Resource.Id.tabTextIcon);
txt.Text = "تماس";
txt.SetCompoundDrawablesWithIntrinsicBounds(Resource.Drawable.iconCall, 0, 0, 0);
tablayout.GetTabAt(0).SetCustomView(iconlayout1);

میخوام لیست گروهبندی مطالبمو تو _Layout.cshtml  ( نمایش در تمام صفحات مثل MasterPage در WebForm) نشون بدم چه راهی رو پیشنهاد میدید ؟ خیلی ممنون