Hi Greg,
I've never done one, but it doesn't sound too hard. Just have an Image property that uses INotifyPropertyChanged on your bound objects for the rows. Have a default image in that property. Have a background process that loads the images into the property; the datagrid should look after the rendering itself. The fun part would be the background loading; you probably want a central service that you register each row's model with that will load the appropriate property with the appropriate image. I'm guessing keeping it central will help as you'll probably want to throttle the number of processes accessing the disk etc. Carl. PS - is this now the Greg/Patrick/Carl list? *grin* Carl Scarlett Senior .NET/WPF Developer, UX Designer | Genesis Enterprise Services | Bankwest A: Level 3, Home Zone 3B, 300 Murray Street | Perth | Western Australia | 6000 P: (08) 9369 5161 M: 0408 913 870 E: [email protected] <mailto:[email protected]> Description: cid:[email protected] From: [email protected] [mailto:[email protected]] On Behalf Of Greg Keogh <[email protected]> Sent: Sunday, 2 September 2012 4:33 PM To: "'ozWPF'" <[email protected]> Subject: Lazy loading images Folks, I have a need to lazily load image thumbnails for display in DataGrid rows. I need that sort of effect you see in Windows Explorer tile view where the items appear instantly but the images progressively load and render. Before I start coding this from scratch I thought it might be worth asking if anyone has experience in this sort of thing. In my case, the full sized (~4MB) images are in a folder and I cache thumbnails of different sizes in another common folder location. I have an old WinForms app that generates and uses these cached thumbnails and it works nicely. Now I have to do the same thing in WPF and try to do it with binding in a way that doesn't "fight the system". I have a few handy MarkupExtension classes already that replace strings and icons in the XAML. Perhaps I could write a "smarter" one that lazy loads images, but I'm not sure how the asynchronous arrival of the image would update the UI, nor is it clear how pending loads would be cancelled if the user navigates away to a different screen. Anyway, comments on this general issue would be welcome, before I hoe into the coding and possibly waste time. Greg ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit http://www.symanteccloud.com ______________________________________________________________________ _______________________________________________ ozwpf mailing list [email protected] http://prdlxvm0001.codify.net/mailman/listinfo/ozwpf ________________________________________________________________________ _______ This email has been scanned by the Bankwest Email Security System. ________________________________________________________________________ _______ _______________________________________________________________________________ Unencrypted electronic mail is not secure and may not be authentic. If you have any doubts as to the contents please telephone to confirm. This electronic transmission including any attachments is intended only for those to whom it is addressed. It may contain copyright material or information that is confidential, privileged or exempt from disclosure by law. Any claim to privilege is not waived or lost by reason of mistaken transmission of this information. If you are not the intended recipient you must not distribute or copy this transmission and should please notify the sender. Your costs for doing this will be reimbursed by the sender. We do not accept liability in connection with computer virus, data corruption, delay, interruption, unauthorised access or unauthorised amendment. _______________________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit http://www.symanteccloud.com ______________________________________________________________________
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