Getting String from array?

Hey guy's im trying to load a string from an array(in this case a url) then download the file, but i get this error below:

Argument cannot be Nothing.
Parameter name: address

Here is my code:

    Dim urld As String

    urld = dls.GetValue(dlcount)
    My.Computer.Network.DownloadFile(urld, "image开发者_如何学Pythons/image-" + dlcount.ToString + ".png")
    Form1.o.Text = Form1.o.Text + urld + vbNewLine

dls is the array.

I thought i did everything right but maybe not.

Difficult to say for sure, but it looks like urld is Nothing when you call the DownloadFile method. This would be caused by the call to dls.GetValue(dlcount) returning Nothing.

So it's likely that there's either a problem with the GetValue method itself, or the value of dlcount that you're passing to it is invalid in some way.