hello, i am doing a application how download a image from internet, save it in a folder and display it in a canavas, but how can i do if the image is bigger than the canavas, change the size to 16x16? Thanks in advance
You will want to abandon the backdrop and use DrawPicture in the paint event of the canvas. See http://documentation.xojo.com/index.php/Graphics.DrawPicture
Hi Federico. The Canvas control in Xojo is very flexible, but it takes a bit of getting used to. Here is a link to a great Blog posting with an awesome tutorial: http://alwaysbusycorner.com/2011/09/15/realbasic-canvas-tutorial-lesson-1
This was a huge help for me when I got started. In *very * basic terms, the Canvas has a Graphics object/property . The Graphics object uses Methods to perform tasks, such as Drawing Lines and Drawing Pictures. The way to get to the Graphics object (on the Canvas Object) is in the Paint Event of the Canvas. The Paint Event gets called many times, based on actions in the User Interface, and can also be triggered via the Refresh and Invalidate Methods on the Canvas. Hopefully, this info will help a little bit.
With Xojo, the trick is to sometimes think “Outside In”. Rather than using a Method to act on an object, think about how the User Interface causes Events to fire. As a computer user, I don’t stop to think about all the Events that fire when I perform actions, but working with Xojo to develop desktop applications has given me a real appreciation for the Event driven model.