public async Task <FileContentResult> CaptchaAsync([FromServices] ICaptchaService _captchaServices)
{
//if (_captchaServices == null) throw new ArgumentNullException(nameof(_captchaServices), "ICaptchaServices未注入，请在CaptchaServices的属性ServiceLifetimeAttribute中启用");
var code = await _captchaServices.GenerateRandomCaptchaAsync();
var result = await _captchaServices.GenerateCaptchaImageAsync(code);
return(File(result.CaptchaMemoryStream.ToArray(), "image/png"));
}