要在ASP.NET Core 2.2和Angular 7+应用程序中进行身份验证，可以使用OpenID Connect（OIDC）协议和IdentityServer4作为身份提供者。下面是一个解决方案的示例代码：

1. 首先，创建一个ASP.NET Core 2.2 Web API项目，并添加IdentityServer4 NuGet包。

2. 在Startup.cs文件中进行配置：

public void ConfigureServices(IServiceCollection services)
{
    // 添加身份验证服务
    services.AddAuthentication(options =>
    {
        options.DefaultScheme = "Cookies";
        options.DefaultChallengeScheme = "oidc";
    })
    .AddCookie("Cookies")
    .AddOpenIdConnect("oidc", options =>
    {
        options.Authority = "https://your-identity-server-url";
        options.ClientId = "your-client-id";
        options.ClientSecret = "your-client-secret";
        options.ResponseType = "code";
        options.SaveTokens = true;
        options.GetClaimsFromUserInfoEndpoint = true;
    });

    // 添加MVC服务
    services.AddMvc();
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    // 使用身份验证中间件
    app.UseAuthentication();

    // 配置MVC路由
    app.UseMvc();
}

3. 在Angular 7+应用程序中使用OIDC进行身份验证。

import { UserManager, UserManagerSettings } from 'oidc-client';

export class AuthService {
    private userManager: UserManager;

    constructor() {
        const settings: UserManagerSettings = {
            authority: 'https://your-identity-server-url',
            client_id: 'your-client-id',
            redirect_uri: 'http://localhost:4200/callback',
            response_type: 'code',
            scope: 'openid profile',
            filterProtocolClaims: true,
            loadUserInfo: true
        };

        this.userManager = new UserManager(settings);
    }

    public login(): Promise {
        return this.userManager.signinRedirect();
    }

    public logout(): Promise {
        return this.userManager.signoutRedirect();
    }

    public handleCallback(): Promise {
        return this.userManager.signinRedirectCallback().then(user => {
            // 处理成功的回调
        });
    }
}

4. 在Angular组件中使用AuthService进行身份验证。

import { Component } from '@angular/core';
import { AuthService } from './auth.service';

@Component({
    selector: 'app-root',
    template: `
        Login
        Logout
    `
})
export class AppComponent {
    constructor(private authService: AuthService) {}

    public login(): void {
        this.authService.login();
    }

    public logout(): void {
        this.authService.logout();
    }
}

使用上述代码，您将能够在ASP.NET Core 2.2和Angular 7+应用程序中实现身份验证。