How to create a progress bar while downloading a file using the windows API?
- by Jorge Chayan
i'm working on an application in MS Visual C++ using Windows API that must download a file and place it in a folder.
I have already implemented the download using URLDownloadToFile function, but i want to create a PROGRESS_CLASS progress bar with marquee style while the file is being downloaded, but it doesn't seems to get animated in the process.
This is the function I use for downloading:
BOOL SOXDownload()
{
HRESULT hRez = URLDownloadToFile(NULL,
"url","C:\\sox.zip", 0, NULL);
if (hRez == E_OUTOFMEMORY ) {
MessageBox(hWnd, "Out of memory Error","", MB_OK);
return FALSE;
}
if (hRez != S_OK) {
MessageBox(hWnd, "Error downloading sox.", "Error!", MB_ICONERROR | MB_SYSTEMMODAL);
return FALSE;
}
if (hRez == S_OK) {
BSTR file = SysAllocString(L"C:\\sox.zip");
BSTR folder = SysAllocString(L"C:\\");
Unzip2Folder(file, folder);
::MessageBoxA(hWnd, "Sox Binaries downloaded succesfully", "Success", MB_OK);
}
return TRUE;
}
Later I call inside WM_CREATE (in my main window's message processor):
if (!fileExists("C:\\SOX\\SOX.exe")) {
components[7] = CreateWindowEx(0, PROGRESS_CLASS,
NULL, WS_VISIBLE | PBS_MARQUEE,
GetSystemMetrics(SM_CXSCREEN) / 2 - 80,
GetSystemMetrics(SM_CYSCREEN) / 2 + 25,
200, 50, hWnd, NULL, NULL, NULL);
SetWindowText(components[7], "Downloading SoX");
SendMessage(components[7], PBM_SETRANGE, 0, (LPARAM) MAKELPARAM(0, 50));
SendMessage(components[7], PBM_SETMARQUEE, TRUE, MAKELPARAM( 0, 50));
SOXDownload();
SendMessage(components[7], WM_CLOSE, NULL, NULL);
}
And as I want, I get a tiny progress bar... But it's not animated, and when I place the cursor over the bar, the cursor indicates that the program is busy downloading the file.
When the download is complete, the window closes as i requested: SendMessage(components[7], WM_CLOSE, NULL, NULL);
So the question is how can I make the bar move while downloading the file? Considering that i want it done with marquee style for simplicity.
Thanks in advance.
