public virtual void Advise(string topic, string item)
{
if (IsDisposed)
throw new ObjectDisposedException(GetType().ToString());
if (!IsRegistered)
throw new InvalidOperationException(Resources.NotRegisteredMessage);
if (topic == null)
throw new ArgumentNullException("topic");
if (topic.Length > Ddeml.MAX_STRING_SIZE)
throw new ArgumentException(Resources.StringParameterInvalidMessage, "topic");
if (item == null)
throw new ArgumentNullException("item");
if (item.Length > Ddeml.MAX_STRING_SIZE)
throw new ArgumentException(Resources.StringParameterInvalidMessage, "item");
// Assume the topic name and item name are wild.
var topicHandle = IntPtr.Zero;
var itemHandle = IntPtr.Zero;
// Create a string handle for the topic name if it is not wild.
if (topic != "*")
topicHandle = Ddeml.DdeCreateStringHandle(_InstanceId, topic, Ddeml.CP_WINANSI);
// Create a string handle for the item name if it is not wild.
if (item != "*")
itemHandle = Ddeml.DdeCreateStringHandle(_InstanceId, item, Ddeml.CP_WINANSI);
// Post an advise notification. This will cause an XTYP_ADVREQ transaction for each conversation.
bool result = Ddeml.DdePostAdvise(_InstanceId, topicHandle, itemHandle);
// Free the string handles created earlier.
Ddeml.DdeFreeStringHandle(_InstanceId, itemHandle);
Ddeml.DdeFreeStringHandle(_InstanceId, topicHandle);
// Check the result to see if the post failed.
if (!result)
{
int error = Ddeml.DdeGetLastError(_InstanceId);
string message = Resources.AdviseFailedMessage;
message = message.Replace("${service}", _Service);
message = message.Replace("${topic}", topic);
message = message.Replace("${item}", item);
throw new DdemlException(message, error);
}
}