private async void InternalDownloadImage(string notePath, HtmlNode imgNode)
{
var imgUrl = imgNode.Attributes["src"].Value;
var imgUrlSplits = imgUrl.Split('/');
var fileName = imgUrlSplits[imgUrlSplits.Length - 1];
ImageEntity image;
var savePath = !ImageDao.ImageExists(fileName, out image)
? downloadAndSaveImageToLocal(notePath, imgNode, imgUrl, fileName)
: image.ImgLocalSavePath;
// Replace the image's src attribute to local path.
imgNode.Attributes["src"].Value = savePath;
}
