Urgently ask some application questions for displaying bmp images

luyang

The instructor asked to write an MFC program. The project was derived from CFormview and then split the window. The dialog box on the left and the area for displaying the picture on the right. I used the class derived from CScrollview. I want to implement the following functions: First, pull The scroll bar can change the image accordingly. Second, select an area to zoom in. In short, just like the basic functions of acdsee software. Realize zoom in, zoom out, drag up, down, left and right.
    But CScrollview is too slow, I call its function ScrollToPosition corresponding to the event of mouse movement. Now the instructor requests to achieve the effect of asdsee, the image dragging zoom in and out should be smooth. Can not be as slow and consume memory as CScrollview
    Please teach me a trick, thank you very much !!!!!!!!!

kangjsh

Display the picture and handle the scroll message yourself. Don't have to be so troublesome
You should be made by Bitble, right?

luyang

The function SetDIBitsToDevice now fixes the scrolling. It is to change the value of the second and third parameters.