Call this function within your control's DoPropExchange member function to serialize or initialize a property of type long.
Pointer to the CPropExchange object (typically passed as a parameter to DoPropExchange).
The name of the property being exchanged.
Reference to the variable where the property is stored (typically a member variable of your class).
Default value for the property.
Nonzero if the exchange was successful; 0 if unsuccessful.
The property's value is read from or written to the variable referenced by lValue, as appropriate. If lDefault is specified, it will be used as the property's default value. This value is used if, for any reason, the control's serialization process fails.