Question

hi to all i am trying to get a access a folder in my thread like this

protected string GetFolderName(int OrgID)
{
    string FolderName = string.Empty;
    string[] strDirectories = Directory.GetDirectories(HttpContext.Current.Server.MapPath("~/Uploads/"));
    if (strDirectories.Length > 0)
    {
        for (int count = 0; count < strDirectories.Length; count++)
        {
            string name = strDirectories[count].Substring(strDirectories[count].LastIndexOf("\\") + 1);
            if (name.Contains("_"))
            {
                string companyId = name.Substring(name.LastIndexOf("_") + 1);
                if (Convert.ToInt32(companyId) == OrgID)
                {
                    FolderName = name;
                    break;
                }
            }
        }
    }
    return FolderName;
}

This method is invoked through the thread pool and it’s giving me an error of “Object reference not set to an instance of an object” on this line

string[] strDirectories = Directory.GetDirectories(HttpContext.Current.Server.MapPath("~/Uploads/"));

Please help me out

---

Solution

i used HttpRuntime.AppDomainAppPath in place of HttpContext.Current.Server.MapPath and it works perfectly.

Answer 1

HttpContext.Current returns the current context in the executing thread. The thread pool thread isn’t responsible for any HTTP request, so it doesn’t have a context. The Current property will return null, which is why you’re getting the exception. I suggest you call Directory.GetDirectories() before you transfer to the thread pool. An alternative would be to pass the context instead.

EDIT: If you don’t want to perform Directory.GetDirectories() in the thread pool thread, you could at least evaluate HttpContext.Current.Server.MapPath("~/Uploads/") in the original thread, and make that available to the thread pool. Basically you just want to avoid evaluating HttpContext.Current on the wrong thread.