Attempting to display Progress Bar

[Don57]

I am attempting to draw a progress bar for my encryption program, but am totally confused at the moment. I am successful at creating the pen, but am unable to select the object. The problem is in the device context handle. Do I use the handle created by BeginPaint, or the one created by CreateCompatableDC in WndProc uMsg==WM_PAINT , or do I have to make those calls again to obtain the DC ?



      invoke  CreatePen, PS_SOLID, PenWidth, PenColor                      ; handle returned in eax
      mov     hPen,eax                                                                     ; save the pen handle
     
      invoke  SelectObject, hGlobalDC, hPen
      mov     hPenOld,eax
     
      invoke MoveToEx, hBitmap, 135d, 350d, NULL                               ; set pen for start of draw

      invoke LineTo, hBitmap, 622d, 355d                                             ; draw the line

      invoke    SelectObject, hBitmap, hPenOld
      invoke    DeleteObject, eax

[AParsons]

You could have a look at: http://win32assembly.online.fr/tut18.html

Sorry I can't be of  more help.

[qWord]

Don57,

you have an back buffer (DC+Bitmap), which is used to draw/fill the whole client area or only parts of it?
Why not using windows progress bars?

[drizz]

Take a look here for a custom progressbar:
http://www.masm32.com/board/index.php?topic=15240.msg123821#msg123821

[Don57]

The trouble is that I am trying to draw the status bar on top of a custom bitmap, which is the user interface for the program. I thought that the DC that I established to draw the bitmap would be valid until the program was closed. As I understand it a handle in windows is merely the memory address. For example hInstance for a program is merely it's address in memory, I assumed that that would apply to the DC handle as well.

[qWord]

If you have created the bitmap and the DC, you can uses the handle as long as you wish - if you do not longer need the DC, simply destroy the bitmap and then the DC.
If I understand you right, your client area of the Window is stored in a Bitmap+DC (=UI=hGlobalDC), which you have created? If so, you are copying this DC to the screen while handling WM_PAINT? In this case, drawing the status bar would take place when the progress bar's value has changed and not while handling WM_PAINT (you would directly draw to your memory-DC, which holds the UI).
you may supply your code?

Code Select Expand

.elseif uMsg == WM_PAINT
    invoke BeginPaint,hWnd,ADDR ps
    mov edx,ps.rcPaint.right
    sub edx,ps.rcPaint.left
    mov ecx,ps.rcPaint.bottom
    sub ecx,ps.rcPaint.top
    invoke BitBlt,ps.hdc,ps.rcPaint.left,ps.rcPaint.top,edx,ecx,hGlobalDC,ps.rcPaint.left,ps.rcPaint.top,SRCCOPY
    invoke EndPaint,hWnd,ADDR ps

...
.elseif uMsg == ...
    ; Progress bar's value has changed!
    ; draw to hGlobalDC ( you may define a function for that task)
    ...
    ; fill rect-structure with region to update
    invoke InvalidateRect,hWnd,ADDR rect,FALSE

[Don57]

Still very confused. Here are some snippets of code.


   WndProc proc hWnd:HWND, uMsg:UINT, wParam, lParam

     LOCAL  ps:PAINTSTRUCT
     LOCAL  hdc:HDC                                                           
     LOCAL  hMemDC:HDC                                                     
     LOCAL  rect:RECT


     .IF uMsg==WM_CREATE

                invoke LoadBitmap, hInstance, OPENING_SCREEN               
                mov hBitmap, eax                                                           

     .ELSEIF uMsg==WM_PAINT

                invoke BeginPaint, hWnd, addr ps                           
                mov  hdc,eax                                                     

                invoke CreateCompatibleDC, hdc                             
                mov  hMemDC,eax                                               
                                                                           

                mov  hGlobalDC,eax                                         ; DC for use in other procs


                invoke SelectObject, hMemDC, hBitmap                     
                invoke GetClientRect, hWnd, addr rect                     
                                                                         

                invoke BitBlt, hdc,0,0,rect.right,\                        ; transfer to display buffer
                               rect.bottom,hMemDC,\
                               0,0,SRCCOPY


                invoke DeleteDC, hMemDC                                    ; delete the device context
                invoke EndPaint, hWnd, addr ps                             ; free DC handle

.ELSEIF uMsg==WM_LBUTTONDOWN                                          ; if user left click window

                   mov  eax,lParam                                         ; get the mouse co-ordinates
                   push eax                                                ; save them
                   and  eax,0FFFFh                                         ; we just want the last word
                   cwde                                                    ; create a double word
                   mov  dwMouseX,eax                                       ; save the X position
                   pop  eax                                                ; get lParam again
                   shr  eax,16d                                            ; put the high word in the low word
                   mov  dwMouseY,eax 


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

The call to   Progress_Bar proc  is after each block of data is written from the buffer. The buffer size is set according to the system granularity.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Progress_Bar proc


     invoke  CreatePen, PS_SOLID, PenWidth, PenColor                     
     mov     hPen,eax                                                     
     
     
      invoke  SelectObject, hGlobalDC, hPen
      mov     hPenOld,eax
     
     
      invoke MoveToEx, hBitmap, 135d, 350d, NULL                               ; set pen for start of draw

      invoke LineTo, hBitmap, 622d, 355d                                             ; draw the line  arbitrary co-ordinates to get it working



      invoke    SelectObject, hBitmap, hPenOld
      invoke    DeleteObject, eax

    ret

   Progress_Bar endp

[jj2007]

> invoke DeleteDC, hMemDC

Before doing that, you should deselect the bitmap.

[qWord]

Still very confused. Here are some snippets of code.
[...]

You are trying to use a bitmap like a DC - that won't work: You must select the loaded bitmap into your global DC (this is done at initialization).
In the attachment an example.

qWord

[Don57]

I just downloaded your code, there is quite a bit there. It will take me a while to read over. It looks like you spent a bit of time writting it. Thank you. :clap: