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can I load image from URL RSS

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Last post Aug 14, 2011 01:02 PM by nathanael.jones@gmail.com

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hardeepsingh

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80 Points

16 Posts

can I load image from URL

Mar 15, 2004 05:51 PM|LINK
when I load an external image like this: string srcPhoto = Request.QueryString["img"]; System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(srcPhoto); it gives error: Exception Details: System.ArgumentException: URI formats are not supported. Source Error: Line 28: //create a image object containing the photograph to watermark Line 29: string srcPhoto = Request.QueryString["img"]; Line 30: System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(srcPhoto); Line 31: int phWidth = imgPhoto.Width; Line 32: int phHeight = imgPhoto.Height; is there any other way to load image from url to System.Drawing.Image imgPhoto Thanks for your help.
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Carsinigin

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40 Points

8 Posts
Re: can I load image from URL

Mar 15, 2004 08:08 PM|LINK
What I would do is use the System.Net.WebClient object to download the file to the localdrive and then open it.
```
System.Net.WebClient objWebClient = new System.Net.WebClient
objWebClient.DownloadFile(URL, FILENAME)
System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(FILENAME)
```
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hardeepsingh

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80 Points

16 Posts

Re: can I load image from URL

Mar 16, 2004 12:23 PM|LINK
Thanks for the reply. That's a good idea and I'll try that.
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sac87126

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190 Points

41 Posts

Re: can I load image from URL

Mar 16, 2004 02:45 PM|LINK
If you want to avoid saving the image to the local drive you cal load it into memory directly. I use a utility function to do it... private void LoadImageFromURL( string URL, ref Bitmap Img ) { const int BYTESTOREAD = 10000; WebRequest myRequest = WebRequest.Create( URL ); WebResponse myResponse = myRequest.GetResponse(); Stream ReceiveStream = myResponse.GetResponseStream(); BinaryReader br = new BinaryReader( ReceiveStream ); MemoryStream memstream = new MemoryStream(); byte[] bytebuffer = new byte[ BYTESTOREAD ]; int BytesRead = br.Read( bytebuffer, 0, BYTESTOREAD ); while ( BytesRead > 0 ) { memstream.Write( bytebuffer, 0, BytesRead ); BytesRead = br.Read( bytebuffer, 0, BYTESTOREAD ); } Img = new Bitmap( memstream ); }
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rafv

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190 Points

38 Posts

Re: can I load image from URL

Mar 17, 2004 01:18 PM|LINK
I think this sample could help you! http://samples.gotdotnet.com/quickstart/util/srcview.aspx?path=/quickstart/winforms/Samples/GDIPlus/Images/Images.src&file=CS\GDIPImages.cs&font=3
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Javaman59

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2 Points

1 Post

Re: can I load image from URL

Jun 10, 2009 01:06 AM|LINK

Update - June 2009

I had to solve the problem of uploading an image from a URI to memory, and, after considerable searching, I found this solution (LoadImageFromUrl, in this thread, by sac87126). It surprising difficult, but it does work. So thankyou, sac, from 2009!

Probably WCF offers a better way to do it. http://stackoverflow.com/questions/104797/wcf-service-for-receiving-image.
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afetchko

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13 Points

13 Posts

Re: can I load image from URL

Aug 12, 2011 05:48 PM|LINK

This worked for me (after a little formatting)...

VB version of code from sac87126

    Private Sub LoadImageFromURL(URL As String, ByRef Img As Drawing.Bitmap)
        Const BYTESTOREAD As Integer = 10000
        Dim myRequest As WebRequest = WebRequest.Create(URL)
        Dim myResponse As WebResponse = myRequest.GetResponse()
        Dim ReceiveStream As Stream = myResponse.GetResponseStream()
        Dim br As New BinaryReader(ReceiveStream)
        Dim memstream As New MemoryStream()
        Dim bytebuffer As Byte() = New Byte(BYTESTOREAD - 1) {}
        Dim BytesRead As Integer = br.Read(bytebuffer, 0, BYTESTOREAD)
        While BytesRead > 0
            memstream.Write(bytebuffer, 0, BytesRead)
            BytesRead = br.Read(bytebuffer, 0, BYTESTOREAD)
        End While
        Img = New Drawing.Bitmap(memstream)
    End Sub
- Edited by afetchko on Aug 12, 2011 05:50 PM
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nathanael.jo...

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137 Points

37 Posts

Re: can I load image from URL

Aug 14, 2011 01:02 PM|LINK

Is this for a publicly accessible website? Allowing arbitrary URLs in the querystring is a vunerability unless you have some way of limiting them to 'safe zones' or you sign the request url with HMAC256.

I recently implemented this feature in the ImageResizing.net library, as the RemoteReader plugin.

The code is open-source, so feel free to download it and take a look at the souce code to see how to implement the request signing and security.

Also, I'd suggest using url-safe base64 encoding for the remote URL to prevent issues with IIS's request parsing.