// todo ...
// .... others code ...
}

 // startup.cs 
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    // 配置 
    app.UseQQAuthentication(new Microsoft.AspNetCore.Authentication.QQ.QQAuthenticationOptions()
            {
                ClientId = "[you client id]",
                ClientSecret ="[you client Secret]",
            });

    // .... others code ...
}

// GET: /Account/ExternalLoginCallback
[HttpGet]
[AllowAnonymous]
public async Task<IActionResult> ExternalLoginCallback(string returnUrl = null, string remoteError = null)
{ 
    // .... others code ...
    // .....
  
    // Получение информации о пользователе, который вошёл в систему (using Microsoft.AspNetCore.Authentication.QQ;)
    var loginInfo = await HttpContext.Authentication.GetExternalQQLoginInfoAsync();
    
    // todo ...
    // .... others code ...
}

 // startup.cs 
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    // 配置 
    app.UseWeixinAuthentication(new Microsoft.AspNetCore.Authentication.Weixin.WeixinAuthenticationOptions()
            {
                ClientId = "[you client id]",
                ClientSecret ="[you client Secret]",
            });

    // .... others code ...
}

// GET: /Account/ExternalLoginCallback
[HttpGet]
[AllowAnonymous]
public async Task<IActionResult> ExternalLoginCallback(string returnUrl = null, string remoteError = null)
{ 
    // .... others code ...
    // .....
  
    // Получение информации о пользователе, который вошёл в систему (using Microsoft.AspNetCore.Authentication.Weixin;)
    var loginInfo = await HttpContext.Authentication.GetExternalWeixinLoginInfoAsync();
    
    // todo ...
    // .... others code ...
}

 // startup.cs 
public void ConfigureServices(IServiceCollection services)
{
    // .... others code ...
    // 配置 
    services.AddAuthentication() 
        .AddQQAuthentication(options =>
        {
            options.ClientId = "[you app id]";
            options.ClientSecret = "[you app secret]";
        });

    // .... others code ...
}

// GET: /Account/ExternalLoginCallback
[HttpGet]
[AllowAnonymous]
public async Task<IAActionResult> ExternalLoginCallback(string returnUrl = null, string remoteError = null)
{ 
    // .... others code ...
    // .....
  
    // Получение информации о пользователе, который вошёл в систему (using Microsoft.AspNetCore.Authentication.QQ;)
    var loginInfo = await HttpContext.GetExternalQQLoginInfoAsync();
    
    // todo ...
    // .... others code ...
}
 

 // startup.cs 
public void ConfigureServices(IServiceCollection services)
{
    // .... others code ...
    // 配置 
    services.AddAuthentication() 
        .AddWeixinAuthentication(options =>
        {
            options.ClientId = "[you app id]";
            options.ClientSecret = "[you app secret]";
        });

    // .... others code ...
}

// GET: /Account/ExternalLoginCallback
[HttpGet]
[AllowAnonymous]
public async Task<IActionResult> ExternalLoginCallback(string returnUrl = null, string remoteError = null)
{ 
    // .... others code ...
    // .....
  
    // Получение информации о пользователе, который вошёл в систему (using Microsoft.AspNetCore.Authentication.Weixin;)
    var loginInfo = await HttpContext.GetExternalWeixinLoginInfoAsync();
    
    // todo ...
    // .... others code ...