使用AuthenticationStateProvider注销用户，并使用Blazor将User.Identity.IsAuthenticated设置为false

services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = "YourAuthenticationScheme";
    options.DefaultChallengeScheme = "YourAuthenticationScheme";
}).AddYourAuthenticationScheme(options =>
{
    // 配置身份验证选项
});

services.AddScoped<AuthenticationStateProvider, YourAuthenticationStateProvider>();

public class YourAuthenticationStateProvider : AuthenticationStateProvider
{
    public override Task<AuthenticationState> GetAuthenticationStateAsync()
    {
        // 获取当前用户的身份验证状态
        // ...

        // 注销用户并将User.Identity.IsAuthenticated设置为false
        var anonymousIdentity = new ClaimsIdentity();
        var anonymousPrincipal = new ClaimsPrincipal(anonymousIdentity);
        var authenticationState = new AuthenticationState(anonymousPrincipal);

        return Task.FromResult(authenticationState);
    }
}

@inject AuthenticationStateProvider AuthenticationStateProvider

<button @onclick="Logout">注销用户</button>

@code {
    private async Task Logout()
    {
        var authenticationState = await AuthenticationStateProvider.GetAuthenticationStateAsync();
        var anonymousIdentity = new ClaimsIdentity();
        var anonymousPrincipal = new ClaimsPrincipal(anonymousIdentity);
        var anonymousAuthenticationState = new AuthenticationState(anonymousPrincipal);

        await AuthenticationStateProvider.SetAuthenticationStateAsync(anonymousAuthenticationState);
    }
}