Improve the previous procedures this evening to increase the scrolling view function. Finally understand the difference and contact of logical coordinates and equipment coordinates, and can be converted with DPTOLP and LPTODP ~ _ *
The logical coordinates are the coordinates of the document. The device coordinates are the coordinates of the view. The view is responding to the message and viewing the document.
The document is generally larger than the view, and the view can only view a part of the document, drag the scroll bar, change the part of the document displayed in the view, so the logical coordinates below the mouse below will change; my understanding is that the equipment coordinates Change, unless you move the window, or change the location of the view ~ _ *
Is this this? I hope everyone will discuss with me ~~~
When there is no drag scroll bar, logical coordinates and device coordinates are consistent, one drag scroll bar, logical coordinates have disseminated relative to the device coordinates. There is corresponding calculation formula, here I don't give it, you can go Take the book.
