Convert PrintWindow to BitBlt to capture screenshot of a specific window - c++

Question

I have a C++ program to capture the screenshot of a specific window and save it using the following code
int main()
{
GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
RECT rc;
HWND hwnd = FindWindow(NULL,TEXT("Window Title Here"));
if(hwnd == NULL)
{
cout<<"Can't Find Window";
return 0;
}
GetClientRect(hwnd,&rc);
HDC hdcscreen = GetDC(NULL);
HDC hdc = CreateCompatibleDC(hdcscreen);
HBITMAP hbmp = CreateCompatibleBitmap(hdcscreen,rc.right - rc.left,rc.bottom - rc.top);
SelectObject(hdc,hbmp);
PrintWindow(hwnd,hdc,NULL);
BitmapToJpg(hbmp,rc.right - rc.left,rc.bottom-rc.top); //Function to convert hbmp bitmap to jpg
DeleteDC(hdc);
DeleteObject(hbmp);
ReleaseDC(NULL,hdcscreen);
}
This code works for many of the windows, but for some of the windows, the output is a black image with correct width and height. On searching I found a solution to use BitBlt(). But I cannot figure out how to replace PrintWindow() with BitBlt() and output to a HBITMAP. Help Need

Answer 1

First, replace hdcscreen by hdcwnd, which you get with GetDC(hwnd) instead of GetDC(NULL). It probably won't change anything, but it is more adequate, even with PrintWindow().
Then, just replace :
PrintWindow(hwnd,hdc,NULL);
By :
BitBlt( hdc, 0, 0, rc.right - rc.left,rc.bottom-rc.top, hdcwnd, 0, 0, SRCCOPY );