private async void GetCaptchaImage() { var captcha = await DataRequester.GetCaptchaImage(); if (captcha == null) { PopupMessage.DisplayMessage(StringUtil.GetString("GetCaptchaFailed")); CaptchaImage.Source = new BitmapImage(new Uri("ms-appx:///Assets/CaptchaFailed.png")); return; } if (!string.IsNullOrEmpty(captcha.Img_Base64)) { NeedCaptcha = true; ResUtil.SetBase64ToImage((BitmapSource)CaptchaImage.Source, captcha.Img_Base64); } else { NeedCaptcha = false; } }