private void BtnUploadImageClick(object sender, EventArgs e)
{
var dirName = string.Format("/{0}/{1}", DateTime.Now.ToString("yyyy"), DateTime.Now.ToString("MM"));
var dir = BlogService.GetDirectory(dirName);
var file = BlogService.UploadFile(txtUploadImage.PostedFile.InputStream, txtUploadImage.PostedFile.FileName, dir, true);
txtContent.Text += string.Format("<img src=\"{0}\" />", file.AsImage.ImageUrl);
}