学习ASP.NET Core Blazor编程系列三十——JWT登录（4）

吕淦 · 发表于 2023-3-19 15:41:26

至此关于Blazor的内容，先写到这里，我们基本上完成了登入、增加、删除、查询、修改等功能，应对一般的应用，已经足够。今天实现登录功能。有登入，必然要有登出，本文我们来介绍一下如何登出。

1. 在Visual Studio 2022的解决方案资源管理器中，鼠标左键选中“Pages”文件夹，右键单击，在弹出菜单中选择“添加—>Razor组件…”，并将组件命名为“Logout.razor”。登出组件的功能是用于退出登入，返回首面。其代码如下：

@page "/Logout"@using BlazorAppDemo.Auth;@inject IAuthService authService@inject NavigationManager navigation @code { protected override async Task OnInitializedAsync() { await authService.LogoutAsync(); navigation.NavigateTo("/"); }}

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2. 在Visual Studio 2022的解决方案管理器中，使用鼠标左键，双击TokenManager.cs文件，对代码进行修改。具体代码如下：

using BlazorAppDemo.Models;using System.Collections.Concurrent; namespace BlazorAppDemo.Utils{ public class TokenManager { private const string TOKEN = "authToken"; private static readonly ConcurrentDictionary tokenManager; static TokenManager() { tokenManager=new ConcurrentDictionary(); } public static ConcurrentDictionary Instance { get { return tokenManager; } } public static string Token { get { return TOKEN; } } public static bool RemoveToken(string token) { if (tokenManager.TryRemove(token,out UserToken delUserToken)) { Console.WriteLine($"delete token {delUserToken.Token}"); return true; } else { Console.WriteLine($"unable delete token {delUserToken.Token}"); return false; } } }}

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3.在Visual Studio 2022的解决方案资源管理器中，鼠标左键双击“Api”文件夹中的 “AuthController.cs”文件，将此文件中的Logout方法的代码补全。代码如下：

using BlazorAppDemo.Models;using BlazorAppDemo.Utils;using Microsoft.AspNetCore.Http;using Microsoft.AspNetCore.Identity;using Microsoft.AspNetCore.Mvc;using Microsoft.Extensions.Configuration;using Microsoft.IdentityModel.Tokens;using Newtonsoft.Json.Linq;using System.IdentityModel.Tokens.Jwt;using System.Security.Claims;using System.Text; namespace BlazorAppDemo.Api{ [Route("api/[controller]")] [ApiController] public class AuthController : ControllerBase { private readonly IJWTHelper jwtHelper; public AuthController(IJWTHelper _IJWTHelper) { this.jwtHelper = _IJWTHelper; } [HttpPost("Login")] public async Task Login(UserInfo userInfo) { //Demo用 if (userInfo.UserName == "admin" && userInfo.Password == "111111") { return BuildToken(userInfo); } else { UserToken userToken = new UserToken() { StatusCode = System.Net.HttpStatusCode.Unauthorized, IsSuccess = false }; return userToken; } } /// /// 建立Token /// /// /// private UserToken BuildToken(UserInfo userInfo) { string jwtToken = jwtHelper.CreateJwtToken(userInfo); //建立UserToken，回传客户端 UserToken userToken = new UserToken() { StatusCode = System.Net.HttpStatusCode.OK, Token = jwtToken, ExpireTime = DateTime.Now.AddMinutes(30), IsSuccess= true }; return userToken; } [HttpGet("Logout")] public async Task Logout() { bool flag= TokenManager.RemoveToken(TokenManager.Token); var response = new UserToken(); response.IsSuccess = !flag; return response; } }}

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4.在Visual Studio 2022的解决方案资源管理器中，鼠标左键选中“Auth”文件夹中的 “AuthService.cs”文件，将此文件中的LogoutAsync方法中添加如下代码：

using BlazorAppDemo.Models;using BlazorAppDemo.Utils;using Microsoft.AspNetCore.Components.Authorization;using Microsoft.AspNetCore.Identity;using Newtonsoft.Json;using Newtonsoft.Json.Linq;using System.Collections.Concurrent;using System.Net.Http;using System.Text; namespace BlazorAppDemo.Auth{ public class AuthService : IAuthService { private readonly HttpClient httpClient; private readonly AuthenticationStateProvider authenticationStateProvider; private readonly IConfiguration configuration; private readonly Api.AuthController authController; private readonly string currentUserUrl, loginUrl, logoutUrl; public AuthService( HttpClient httpClient, AuthenticationStateProvider authenticationStateProvider,
IConfiguration configuration,Api.AuthController authController) { this.authController = authController; this.httpClient = httpClient; this.authenticationStateProvider = authenticationStateProvider; this.configuration = configuration; currentUserUrl = configuration["AuthUrl:Current"] ?? "Auth/Current/"; loginUrl = configuration["AuthUrl:Login"] ?? "api/Auth/Login"; logoutUrl = configuration["AuthUrl:Logout"] ?? "/api/Auth/Logout/"; } public async Task LoginAsync(UserInfo userInfo) { response.Content.ReadFromJsonAsync(); var result = authController.Login(userInfo); var loginResponse = result.Result.Value; if (loginResponse != null && loginResponse.IsSuccess) { TokenManager.Instance.TryAdd(TokenManager.Token, loginResponse); ((ImitateAuthStateProvider)authenticationStateProvider).NotifyUserAuthentication(loginResponse.Token); httpClient.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("bearer",
loginResponse.Token); return loginResponse; } return new UserToken() { IsSuccess = false }; } public async Task LogoutAsync() { var result = authController.Logout(); var logoutResponse = result.Result.Value; ((ImitateAuthStateProvider)authenticationStateProvider).NotifyUserLogOut(); httpClient.DefaultRequestHeaders.Authorization = null; return logoutResponse; } }}

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LogoutAsync方法：

将token从TokenManger实例中移除
通知前面页面更新登录状态
将request中的header参数bearer token移除。

5. 在Visual Studio 2022的解决方案管理器中，使用鼠标左键，双击ImitateAuthStateProvider.cs文件，对代码进行修改。具体代码如下：

using BlazorAppDemo.Models;using BlazorAppDemo.Utils;using Microsoft.AspNetCore.Components.Authorization;using System.Net.Http;using System.Security.Claims; namespace BlazorAppDemo.Auth{ public class ImitateAuthStateProvider : AuthenticationStateProvider { private readonly IJWTHelper jwt; private AuthenticationState anonymous; private readonly HttpClient httpClient; public ImitateAuthStateProvider(IJWTHelper _jwt, HttpClient httpClient) { anonymous = new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity())); jwt = _jwt; this.httpClient = httpClient; } bool isLogin = false; string token = string.Empty; public override Task GetAuthenticationStateAsync() { //确认是否已经登录 UserToken userToken; TokenManager.Instance.TryGetValue(TokenManager.Token,out userToken); string tokenInLocalStorage=string.Empty; if (userToken != null) { tokenInLocalStorage = userToken.Token; } if (string.IsNullOrEmpty(tokenInLocalStorage)) { //沒有登录，则返回匿名登录者 return Task.FromResult(anonymous); } //將token取出转换为claim var claims = jwt.ParseToken(tokenInLocalStorage); //在每次request的header中都将加入bearer token httpClient.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("bearer",
tokenInLocalStorage); //回传带有user claim的AuthenticationState return Task.FromResult(new AuthenticationState(new ClaimsPrincipal(new ClaimsIdentity(claims, "jwt")))); } public void Login(UserInfo request) { //1.验证用户账号密码是否正确 if (request == null) { isLogin=false; } if (request.UserName == "user" && request.Password == "111111") { isLogin = true; token= jwt.CreateJwtToken(request); Console.WriteLine($"JWT Token={token}"); } NotifyAuthenticationStateChanged(GetAuthenticationStateAsync()); } public void NotifyUserAuthentication(string token) { var claims = jwt.ParseToken(token); var authenticatedUser = new ClaimsPrincipal(new ClaimsIdentity(claims, "jwt")); var authState = Task.FromResult(new AuthenticationState(authenticatedUser)); NotifyAuthenticationStateChanged(authState); } public void NotifyUserLogOut() { var authState = Task.FromResult(anonymous); NotifyAuthenticationStateChanged(authState); } }}

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6. 在Visual Studio 2022的解决方案管理器中，使用鼠标左键，双击MainLayout.razor文件，对代码进行修改。具体代码如下：

@using BlazorAppDemo.Pages@inherits LayoutComponentBase BlazorAppDemo [url=https://docs.microsoft.com/aspnet/]About[/url] 你好, @context.User.Identity.Name![url=https://www.cnblogs.com/Logout]Logout[/url] @Body [size=20px]检测到登录超时，请重新[url=https://www.cnblogs.com/login]登录[/url]！
[/size]

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7. 在Visual Studio 2022的菜单栏上，找到“调试-->开始调试”或是按F5键，Visual Studio 2022会生成BlazorAppDemo应用程序。浏览器会打开登录页面。我们在登录页面的用户名输入框中输入用户名，在密码输入框中输入密码，点击“登录”按钮，进行登录。我们进入了系统，在页面的右上角处，会出现登录用户的用户名，与一个“Logout”按钮。如下图。

来源:https://www.cnblogs.com/chillsrc/archive/2023/03/19/17232979.html
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