Error handling for methods can be performed using either return
codes or exceptions, depending on the value of this property.
If the ThrowError property is set to False, methods will
return a status value indicating success or failure. Applications
should check the return value of each method and use the
LastError and LastErrorString properties to determine
the cause of any error.
If the ThrowError property is set to True, errors occurring
within the control will be raised to the host application as ActiveX
exceptions. In addition, the OnError event will fire. This
allows applications to use language-specific exception handling
mechanisms, such as Visual Basic error handling, instead of checking
individual return values after each method call.
Even when the ThrowError property is set to True, the
LastError and LastErrorString properties will still be
updated with information about the most recent error.
If an error occurs while accessing a property value, an exception
will be raised regardless of the value of the ThrowError
property. However, the OnError event will not be fired for
property access errors.