Identity用户管理入门六（判断是否登录）

目前用户管理的增删改查及登录功能已经全部实现，但存在一个问题，登录后要取消登录按钮显示退出按钮，未登录应该有注册按钮，现实现过程如下

一、Startup.cs中增加服务

app.UseAuthentication();

二、修改用户管理主页

注入服务

@inject SignInManager<IdentityUser> SignInManager

修改视图代码，判断当前用户是否登录

@if (SignInManager.IsSignedIn(User)) { <form asp-action="Logout" method="post" id="logoutForm"> <a href="javascript:document.getElementById('logoutForm').submit()">退出</a> </form> } else { <a asp-action="Register">注册</a> <a asp-action="Login">登录</a> }

登录及未登录显示效果

修改后完整代码

@using Microsoft.AspNetCore.Identity
@model IEnumerable<Microsoft.AspNetCore.Identity.IdentityUser>
@inject SignInManager<IdentityUser> SignInManager
@{
    ViewData["Title"] = "Index";
}

<h1>Index</h1>
<h1>@ViewData["User"]</h1>
@if (SignInManager.IsSignedIn(User))
{
    <form asp-action="Logout" method="post" id="logoutForm">
        <a href="javascript:document.getElementById('logoutForm').submit()">退出</a>
   </form>
}
else
{
    <a asp-action="Register">注册</a>
    <a asp-action="Login">登录</a>
}
<table class="table table-bordered">
    <tr>
        <th>@Html.DisplayNameFor(u => u.Id)</th>
        <th>@Html.DisplayNameFor(u => u.UserName)</th>
        <th>@Html.DisplayNameFor(u => u.Email)</th>
        <th>@Html.DisplayNameFor(u => u.PhoneNumber)</th>
        <th>操作</th>
    </tr>
    @foreach (var item in Model)
    {
        <tr>
            <td>@item.Id</td>
            <td>@item.UserName</td>
            <td>@item.Email</td>
            <td>@item.PhoneNumber</td>
            <td>
                <a asp-action="EditUser" asp-route-id="@item.Id" type="button" class="btn btn-success btn-xs">修改</a>
                <a asp-action="Delete" asp-route-id="@item.Id" type="button" class="btn  btn-danger btn-xs" size="">删除</a>
            </td>
        </tr>
    }
</table>

也可以把用户列表中加上如果没有登录不显示编辑、删除按钮

@using Microsoft.AspNetCore.Identity
@model IEnumerable<IdentityUser>
@inject SignInManager<IdentityUser> SignInManager
@{
    ViewData["Title"] = "Index";
}

<h1>Index</h1>

@if (SignInManager.IsSignedIn(User))
{
    <form asp-action="Logout" method="post" id="logoutForm">
        <a href="javascript:document.getElementById('logoutForm').submit()">退出</a>
    </form>
}
else
{
    <a asp-action="Register">注册</a>
    <a asp-action="Login">登录</a>
}
<table class="table table-bordered">
    <tr>
        <th>@Html.DisplayNameFor(u => u.Id)</th>
        <th>@Html.DisplayNameFor(u => u.UserName)</th>
        <th>@Html.DisplayNameFor(u => u.Email)</th>
        <th>@Html.DisplayNameFor(u => u.PhoneNumber)</th>
        @if (SignInManager.IsSignedIn(User))
        {
            <th>操作</th>
        }
    </tr>
    @foreach (var item in Model)
    {
        <tr>
            <td>@item.Id</td>
            <td>@item.UserName</td>
            <td>@item.Email</td>
            <td>@item.PhoneNumber</td>
            @if (SignInManager.IsSignedIn(User))
            {
                <td>
                    <a asp-action="EditUser" asp-route-id="@item.Id" type="button" class="btn btn-success btn-sm ">修改</a>
                    <a asp-action="Delete" asp-route-id="@item.Id" type="button" class="btn  btn-danger btn-sm">删除</a>
                </td>
            }
        </tr>
    }
</table>

修改后的视图

未登录

登录后显示

熟悉工作流程后上述代码可直接使用新建asp.net core项目中的个人验证，自动配置好以上基础框架