IPB_Session interface:
ProcessPBMessage method
Description
Checks the PowerBuilder message queue and, if there is a message in the queue, attempts to process it.
Syntax
ProcessPBMessage()
Return Values
pbboolean. Returns true if a PowerBuilder message was processed, and false otherwise.
Examples
This message loop in a WinMain function processes a PowerBuilder message if a message has been received and an IPB session is running:
try
{
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
// Call to ProcessPBMessage
if (session)
session->ProcessPBMessage();
}
This overloaded WindowProc function in an MFC application processes a PowerBuilder message:
LRESULT CCallPBVCtrl::WindowProc(UINT message,
WPARAM wParam, LPARAM lParam)
{
d_session->ProcessPBMessage();
return CDialog::WindowProc(message, wParam, lParam);
}
Usage
Each time this function is called, it attempts to retrieve a message from the PowerBuilder message queue and process it. It is similar to the PowerBuilder Yield function; however, ProcessPBMessage processes only one message at a time, and it processes only PowerBuilder messages. The Yield function also processes Windows messages.
Use this function when PowerBuilder windows or visual controls are called from C++ applications or from extensions to ensure that events posted to the PowerBuilder message queue are processed.
If the function is not inserted in the C++ application in a way that results in it being called repeatedly, posted events are not processed in the PowerBuilder application.
For most applications, ProcessPBMessage can be inserted in a message loop in the WinMain function. If you use Microsoft Foundation Classes (MFC), you cannot modify the built–in message loop. To ensure that the ProcessPBMessage function is called repeatedly, you can overload the CWnd::WindowProc function and insert ProcessPBMessage into the overloaded function.