"Value of 'null' is not valid for stream" - image

Question

Attempting to download an image from a URL into memory. Getting an error on the response stream.
Exception calling "FromStream" with "1" argument(s): "Value of 'null' is not valid for 'stream'."
Function Download-Image {
$req = [System.Net.WebRequest]::Create
("http://www.wired.com/images_blogs/business/2012/12/google.jpg")
$response = $req.GetResponse()
$ResponseStream = $Response.GetResponseStream()
[System.IO.Stream]$stream = $ResponseStream
#$response.close()
}
[byte[]]$image = Download-Image
Add-Type -AssemblyName System.Windows.Forms
$img = [System.Drawing.Image]::FromStream([System.IO.MemoryStream]$image)
[System.Windows.Forms.Application]::EnableVisualStyles()
$pictureBox = new-object Windows.Forms.PictureBox
$pictureBox.Width = $img.Width
$pictureBox.Height = $img.Height
$pictureBox.Image = $img
$form = new-object Windows.Forms.Form
$form.Width = $img.Width
$form.Height = $img.Height
$form.AutoSize = $True
$form.AutoSizeMode = "GrowAndShrink"
$form.Icon = $icon
$form.controls.add($pictureBox)
$form.Add_Shown( { $form.Activate() } )
$form.ShowDialog()

Answer 1

You need to return value from function after assignment:
Function Download-Image {
$req = [System.Net.WebRequest]::Create
("http://www.wired.com/images_blogs/business/2012/12/google.jpg")
$response = $req.GetResponse()
$ResponseStream = $Response.GetResponseStream()
[System.IO.Stream]$stream = $ResponseStream
#$response.close()
$req
}
In your case $image variable just have a value of $null:
[byte[]]$image = Download-Image
Updated:
To download image as byte array you can use solution from this post:
var webClient = new WebClient();
byte[] imageBytes = webClient.DownloadData("http://www.google.com/images/logos/ps_logo2.png");