Check if Image Exists on Remote Site ASP.NET VB - asp.net

Question

I'm trying to get my website to detect if an image exists on the server, display if it does, if it doesn't display another image (which is just called blank.png).
I have tried to use Server.MapPath with relative pathings but havent been able to get it to work. When using Server.MapPath and checking in the broswer after the page has loaded i uses the full path of the file (eg G:\domain\path\blank.png).
If i use The normal path (Dim sImagePath As String = "\Images\DriversNew\"'). The image will display, but the check for whether the image exists or not always returns false. I'm assuming its to do with the physical location of the file.
'Dim sImagePath As String = Server.MapPath("Images/DriversNew/")
Dim sImagePath As String = "\Images\DriversNew\"
Dim sHeadshot As String = sImagePath & dsDriver.Tables("Driver").Rows(0).Item("Name") & ".png"
If File.Exists(sHeadshot) Then
imgDriver.ImageUrl = sHeadshot
Else
imgDriver.ImageUrl = sImagePath & "Blank.png"
End If
Any advice? I know its something simple, but with the reading ive been doing it hasnt been able to get it working on the site.
Thanks, much appreciated!

Answer 1

Assuming that your database column Name contains only the short filename (i.e. no directory path information or folder names) then you can do this:
String nameFromDatabase = (String)dsDriver.Tables("Driver").Rows[0]["Name"] + ".png";
String appRootRelativeHttpResourcePath = "~/Images/DriversNew/" + nameFromDatabase;
String localFileSystemPath = Server.MapPath( appRootRelativeHttpResourcePath );
if( File.Exists( localFileSystemPath ) ) {
imgDriver.ImageUrl = appRootRelativeHttpResourcePath; // you can specify app-root-relative URLs ("~/...") here
}
else {
imgDriver.ImageUrl = "~/Images/DriversNew/Blank.png";
}