C / C++ / MFC

14-Nov-11 16:32

I thought I got this right, but it's my first time converting numbers to letters, in a message I'm building to send to a text hwnd.

// Calculate the MegaBytes Downloaded		
		dBytes = ((float)ulProgress / (1024*1024));
		dTotal = ((float)ulProgressMax / (1024*1024));

		if ((dBytes > 0.10) && (dTotal > 0.10)) {
			// Convert double to WCHAR
			WCHAR str0[120];
			WCHAR str1[120];
			str0[0] = L'\0';
			str1[0] = L'\0';
			wprintf(str0, L"%.2f", dBytes);
			wprintf(str1, L"%.2f", dTotal);

David Crow14-Nov-11 16:54

14-Nov-11 16:54

jkirkerx wrote:
str0[0] = L'\0';
str1[0] = L'\0';

Unnecessary.

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Peter_in_278014-Nov-11 17:06

Peter_in_2780

14-Nov-11 17:06

jkirkerx wrote:
wprintf(str0, L"%.2f", dBytes);
wprintf(str1, L"%.2f", dTotal);
Don't you mean wsprintf?

There are probably close to aleph-null ways to do it.

Peter

Software rusts. Simon Stephenson, ca 1994.

jkirkerx15-Nov-11 6:15

15-Nov-11 6:15

The wsprintf just gave me a f

I tried a char and sprintf, and the values I need came back. I'm new to this, so I thought I could go straight to unicode.

char szTemp0[20];
char szTemp1[20];
sprintf(szTemp0, "%.2f", dBytes); // .10
sprintf(szTemp1, "%.2f", dTotal); // 727.42

David Crow15-Nov-11 7:17

15-Nov-11 7:17

jkirkerx wrote:
The wsprintf just gave me a f

In your original post, you used wprintf() not wsprintf(). They output to two different places.

Have you considered:

TCHAR szTemp0[20];
TCHAR szTemp1[20];
_stprintf(szTemp0, _T("%.2f"), dBytes);
_stprintf(szTemp1, _T("%.2f"), dTotal);

This will handle both Unicode and MBCS.

modified 15-Nov-11 15:07pm.

jkirkerx15-Nov-11 8:43

15-Nov-11 8:43

No.

But I did consider that perhaps I should always use TCHAR when working with Windows stuff like writing registry keys, and sending setting window text.

I change my code to this, and I'm still working with WCHAR on szStatusMessage. The code is inside the IBindStatusCallback in the OnProgress Loop in case your wondering. For me this is uncharted waters, and I sort had to guess at how to work with it.

// Calculate the MegaBytes Downloaded
        dBytes = ((float)ulProgress / (1024*1024));
        dTotal = ((float)ulProgressMax / (1024*1024));
        dPercent = dBytes/dTotal*100;

        if ((dBytes > 0.10) && (dTotal > 0.10)) {
            swprintf_s(szStatusMessage, L"Downloading %.2f MB of %.2f MB [%.1f%%]", dBytes, dTotal, dPercent);
            iMsgLen = wcslen(szStatusMessage);
            szStatusMessage[iMsgLen] = '\0';
        }

David Crow15-Nov-11 9:07

15-Nov-11 9:07

jkirkerx wrote:
szStatusMessage[iMsgLen] = '\0';

Unnecessary.

jkirkerx15-Nov-11 9:53

15-Nov-11 9:53

I took it out, and put it back in.

I wasn't sure how to handle the callback loop, and didn't want to create what I call variables in the loop. So I created the szStatusMessage in the private section of the class. When the loop goes round, some of the messages are longer than others, and the old message doesn't clear when the new message is written to the space, so I put the \0 back in just to get rid of the old message, so the cat writes the entire space. I could experiment with moving it back into the loop, and see what changes I need to make.

David Crow15-Nov-11 10:08

15-Nov-11 10:08

You are misusing swprintf_s(). The second argument is the maximum number of characters to store in the buffer. Correctly used, swprintf_s() will terminate the buffer where necessary.

Try:

swprintf_s(szStatusMessage, sizeof(szStatusMessage), L"Downloading %.2f MB of %.2f MB [%.1f%%]", dBytes, dTotal, dPercent);

jkirkerx15-Nov-11 10:17

15-Nov-11 10:17

Let me look into the proper use, I know there was a ms version wsprintf_s and a ansi version swprintf_s. I moved the variables inside the loop, works ok, but I get squares in the message because I haven't populated it yet.

I guess I should of shown more code, the other half of the if statement, that shows the status message from the callback. I may kill the idea of that message, I don't see anything relevant to it.

if ((dBytes > 0.10) && (dTotal > 0.10)) {
            swprintf_s(szStatusMessage, L"Downloading %.2f MB of %.2f MB [%.1f%%]", dBytes, dTotal, dPercent);
            iMsgLen = wcslen(szStatusMessage);
            szStatusMessage[iMsgLen] = '\0';
        }
        else {
            if (wszStatusText != NULL) {
                int iStatusLen = wcslen(wszStatusText);
                if (iStatusLen < 80) {
                    iMsgLen = wcslen(szStatusMessage);
                    wcsncpy_s(szStatusMessage, wszStatusText, iStatusLen);
                    szStatusMessage[iStatusLen] = '\0';
                }
            }
        }

        // Publish Status Message
        SetWindowText(hWnd_Progress_Text, szStatusMessage);

        // Format the Progress Bar Value
        dPB = (float)ulProgress/ulProgressMax*5000.0;
        SendMessage(hWnd_Progress_Bar, PBM_SETRANGE, 0, MAKELPARAM(0, 5000));
        SendMessage(hWnd_Progress_Bar, PBM_SETPOS, (WPARAM)dPB, 0);

jkirkerx15-Nov-11 15:16

15-Nov-11 15:16

Thanks for the heads up on the swprintf_s. I appreciate the attention to detail and efficiency you gave me today. tough learn today, but it works well.

Changed it to this now.

case BINDSTATUS_DOWNLOADINGDATA:
                // Calculate the MegaBytes Downloaded
                dBytes = ((float)ulProgress / (1024*1024));
                dTotal = ((float)ulProgressMax / (1024*1024));
                dPercent = dBytes/dTotal*100;

                if ((dBytes > 0.10) && (dTotal > 0.10)) {
                    swprintf_s(szStatusMessage, 80, L"Downloading %.2f MB of %.2f MB [%.1f%%]", dBytes, dTotal, dPercent);
                    iMsgLen = wcslen(szStatusMessage);
                    szStatusMessage[iMsgLen] = '\0';
                }
                break;

David Crow16-Nov-11 2:05

16-Nov-11 2:05

jkirkerx wrote:
iMsgLen = wcslen(szStatusMessage);
szStatusMessage[iMsgLen] = '\0';

wcslen() relies upon szStatusMessage being \0 terminated, so these two statements don't do anything useful.

jkirkerx16-Nov-11 6:20

16-Nov-11 6:20

I didn't know that. I'll experiment with removing them and see what happens. I'm sure your right on that. That means less code to type for me in the future.

Thanks Dave,

jkirkerx15-Nov-11 6:34

15-Nov-11 6:34

I used swprintf, I think the wsprintf was for tchars. It will do for now

WCHAR szBytes[20];
WCHAR szTotal[20];
swprintf(szBytes, L"%.2f", dBytes);
swprintf(szTotal, L"%.2f", dTotal);

jkirkerx15-Nov-11 7:18

15-Nov-11 7:18

Alright I'm still learning here so don't laugh, but I was able to consolidate the whole thing into one swprintf_s, to produce my status message. That's pretty cool. I wonder if I should of just used TCHAR and wsprintf_s and went the Microsoft way?

FYI:
I started with vb, so I was use to building strings together with &, or + in JavaScript.

dBytes = ((float)ulProgress / (1024*1024));
dTotal = ((float)ulProgressMax / (1024*1024));

if ((dBytes > 0.10) && (dTotal > 0.10)) {
            swprintf_s(szStatusMessage, L"Downloading %.2f MB of %.2f MB", dBytes, dTotal);
            iMsgLen = wcslen(szStatusMessage);
            szStatusMessage[iMsgLen] = '\0';
}

David Crow15-Nov-11 9:09

15-Nov-11 9:09

jkirkerx wrote:
I started with vb, so I was use to building strings together with &, or + in JavaScript.

You can still do that with MFC's CString class, or with the STL's std::string class.