If I understand you correctly I think a query like this might do the trick. It's written here in the editor, and not compiled, so small syntax adjustments might be necessary

TopicQuery tq = new TopicQuery();

// Initialize text and subject criteria with wildcard filtering
tq.Subject = new StringCriterion();
tq.Subject.WildCardType = WildCardType.Both;
tq.Subject.Value = "subject";

tq.Text = new StringCriterion();
tq.Text.WildCardType = WildCardType.Both;
tq.Text.Value = "text";

//  Specify that the topic must contain a reply with the same wildcard filter as obove
tq.Replies = new ReplyCollectionCriterion();
tq.Replies.Containing = new ReplyCriterion();

tq.Replies.Containing.Subject = new StringCriterion();
tq.Replies.Containing.Subject.WildCardType = WildCardType.Both;
tq.Replies.Containing.Subject.Value = "subject";

tq.Replies.Containing.Text = new StringCriterion();
tq.Replies.Containing.Text.WildCardType = WildCardType.Both;
tq.Replies.Containing.Text.Value = "text";

// Group subject, text and "replies-subquery" on the topic level
CriteriaGroup group1 = new CriteriaGroup();
group1.AddCriterion(tq.Subject);
group1.AddCriterion(LogicalOperator.Or, tq.Text);
group1.AddCriterion(LogicalOperator.Or, tq.Replies);
tq.AddCriteriaGroup(group1); 

// Group subject and text on the "Containing" level
CriteriaGroup group2 = new CriteriaGroup();
group2.AddCriterion(tq.Replies.Containing.Subject);
group2.AddCriterion(LogicalOperator.Or, tq.Replies.Containing.Text);
tq.Replies.Containing.AddCriteriaGroup(group2); 

Thank you Mattias! It looks like it would do what I intend it to do, but it does not work entirely. The ReplyCriterion part seems to match any topic. I isolated that part, the following query returns all topics:

TopicQuery tq = new TopicQuery();
// Only one reply in one topic contains this string
string keyword = "asdfasdfasdf1234";
tq.Replies = new ReplyCollectionCriterion();
tq.Replies.Containing = new ReplyCriterion();
tq.Replies.Containing.Subject = new StringCriterion();
tq.Replies.Containing.Subject.WildCardType = WildCardType.Both;
tq.Replies.Containing.Subject.Value = keyword;
tq.Replies.Containing.Text = new StringCriterion();
tq.Replies.Containing.Text.WildCardType = WildCardType.Both;
tq.Replies.Containing.Text.Value = keyword;
// Group subject and text on the "Containing" level
CriteriaGroup group2 = new CriteriaGroup();
group2.AddCriterion(tq.Replies.Containing.Subject);
group2.AddCriterion(LogicalOperator.Or, tq.Replies.Containing.Text);
tq.Replies.Containing.AddCriteriaGroup(group2); 

No solution for this? We're almost there!

*bump*

Hi,

I've been looking at this same subject recently.  I combined results from a TopicQuery with results from a ReplyQuery - possibly not the most elegant way to proceed but it seems to work fine. It searches both subject and text of all topics and replies.  I've used the WildcardType.Both so it searches for "WildCard on both ends of the value" ("%Word1%", as mentioned above).  Here's my SearchTopic function:

public MessageCollection SearchTopics(string searchText) { MessageCollection searchResults = new MessageCollection();

// The topic query 

TopicQuery tq = new TopicQuery();

// Create subject criteria 

StringCriterion subjectCriterion = new StringCriterion(); subjectCriterion.Value = searchText; subjectCriterion.WildCardType = WildCardType.Both; tq.Subject = subjectCriterion;

// Create text criteria  

StringCriterion textCriterion = new StringCriterion(); textCriterion.Value = searchText; textCriterion.WildCardType = WildCardType.Both; tq.Text = textCriterion;

// Create group for criterion relating to topic subject, text 

CriteriaGroup topicCriteriaGroup = new CriteriaGroup();

// Add criterion to criteriaGroup 

topicCriteriaGroup.AddCriterion(tq.Subject); topicCriteriaGroup.AddCriterion(LogicalOperator.Or, tq.Text);

// Add this group to tq 

tq.AddCriteriaGroup(topicCriteriaGroup);

// Get searched for topics  

int totalTopicItems = 0; searchResults = QueryHandler.GetQueryResult<Community.Forum.Topic, MessageCollection>(tq, Utils.CacheTimeOut.Search, 1, 12, out totalTopicItems);

// The reply query 

ReplyQuery rq = new ReplyQuery();

// Create subject criteria for reply 

StringCriterion replySubjectCriterion = new StringCriterion(); replySubjectCriterion.Value = searchText; replySubjectCriterion.WildCardType = WildCardType.Both; rq.Subject = replySubjectCriterion;

// Create text criteria for reply 

StringCriterion replyTextCriterion = new StringCriterion(); replyTextCriterion.Value = searchText; replyTextCriterion.WildCardType = WildCardType.Both; rq.Text = replyTextCriterion;

// Create group for criterion relating to reply subject, text 

CriteriaGroup replyCriteriaGroup = new CriteriaGroup();

// Add criterion to criteriaGroup 

replyCriteriaGroup.AddCriterion(rq.Subject); replyCriteriaGroup.AddCriterion(LogicalOperator.Or, rq.Text);

// Add this group to rq 

rq.AddCriteriaGroup(replyCriteriaGroup);

// Get searched for replys  

int totalReplyItems = 0; MessageCollection replyResults = QueryHandler.GetQueryResult<Community.Forum.Reply, MessageCollection>(rq, Utils.CacheTimeOut.Search, 1, 12, out totalReplyItems);

// Combine search results from replies with search results from topics 

foreach (Message reply in replyResults) { searchResults.Add(reply); } return searchResults; }