The drawing options. It can be one of the following values.
Only the client area of the window is copied to hdcBlt. By default, the entire window is copied.
If the function succeeds, it returns a nonzero value.
If the function fails, it returns zero.
Note This is a blocking or synchronous function and might not return immediately. How quickly this function returns depends on run-time factors such as network status, print server configuration, and printer driver implementation—factors that are difficult to predict when writing an application. Calling this function from a thread that manages interaction with the user interface could make the application appear to be unresponsive.
The application that owns the window referenced by hWnd processes the PrintWindow call and renders the image in the device context that is referenced by hdcBlt. The application receives a WM_PRINT message or, if the PW_PRINTCLIENT flag is specified, a WM_PRINTCLIENT message.
For more information, see WM_PRINT and WM_PRINTCLIENT.