## Message Function

The Wxutil.h header file in the DirectShow base classes provides a helper function for processing messages.

Function | Description
WaitDispatchingMessages | Waits for a for the HANDLE hObject before dispatching messages. While waiting, messages sent to windows on the thread by SendMessage will be processed.

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WaitDispatchingMessages

Message Function

Waits for a for the HANDLE hObject before dispatching messages. While waiting, messages sent to windows on the thread by SendMessage will be processed.

DWORD WINAPI WaitDispatchingMessages(
HANDLE hObject,
DWORD dwWait,
HWND hwnd = NULL,
UINT uMsg = 0
);

##### Parameters

hObject
  Handle of object to wait for.
dwWait
  Time-out interval in milliseconds.
hwnd
  Handle to a window.
uMsg
  Win32 message.

##### Return Values

If the function succeeds, the return value indicates the event that caused the function to return. If the function fails, the return value is WAIT_FAILED.

The return value on success is one of the following values:

Value | Meaning
WAIT_ABANDONED | The specified object is a mutex (mutual exclusion) object that was not released by the thread that owned the mutex object before the owning thread terminated. Ownership of the mutex object is granted to the calling thread, and the mutex is set to nonsignaled.
WAIT_OBJECT_0 | The state of the specified object is signaled.
WAIT_TIMEOUT | The time-out interval elapsed, and the object's state is nonsignaled.

##### Remarks

This function enables sent messages to be processed while waiting for a handle to a window. Use this function to wait for an object to be processed and to perform mutually exclusive operations, consequently avoiding possible deadlocks in objects with windows.

This helper function is similar to the Win32 WaitForSingleObject function.

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