How to undo drawing images in MFC.?

[mbatra31]

Hi, I want to provide undo/redo drawing feature in MFC dialog based application. I am saving the images dynamically in a vector in OnMouseMove handler code. But when I am going to load the previous image on clicking Undo button, its getting distorted. the last image saved still remains there on the canvas. Can anybody tell me whats the issue with OnMouseMove handler. How the compiler will know when to end saving the image.? Regards,

[Lost User]

mbatra31 wrote:

How the compiler will know when to end saving the image.?

The compiler knows nothing, it's your code that has to do the work. Without seeing some of your code it's impossible to know what is going on.

speaking as ...

[Maximilien]

Don't save the image the "OnMouseMove" event handler, save it in the OnLButtonUp handler (normally when the action is finished); or else you will end up with thousands and thousands of images. How are you saving and putting back the image ? BitBlt ? StretchBlt ? show us some code. If the image is stretched, are you certain you are using the good Width and Height for the bitmap ?

Watched code never compiles.

[mbatra31]

Hi Maximilien, Thanx for your response. I have done that part. I am saving the images in OnLButtonUp event handler only. Thanx & Regards,

[Sunil P V]

Check this link http://www.codeproject.com/Messages/4305065/Re-How-to-Undo-Redo-drawing-operation-in-a-dialog-.aspx[^]

Sunil