ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data.Knowledge Namespace / KnowledgeGraphSearchFilter Class / SearchText Property
Example Version

SearchText Property (KnowledgeGraphSearchFilter)
Gets or sets the search query used to filter the returned rows. This text should abide by the Apache Lucene query syntax.
Syntax
public string SearchText {get; set;}
Example
Submit a Text Search
//On the QueuedTask...
//and assuming you have established a connection to a knowledge graph
//...
//Construct a KG search filter. Search text uses Apache Lucene Query Parser
//syntax - https://lucene.apache.org/core/2_9_4/queryparsersyntax.html
var kg_sf = new KnowledgeGraphSearchFilter()
{
  SearchTarget = KnowledgeGraphNamedTypeCategory.Entity,
  SearchText = "Acme Electric Co.",
  ReturnSearchContext = true,
  MaxRowCount = 10 //Default is 100 if not specified
};

//submit the search - returns a KnowledgeGraphCursor
var e = 0;
using (var kg_rc = kg.SubmitSearch(kg_sf))
{
  //wait for rows to be returned from the server
  //note the "await"...
  while (await kg_rc.WaitForRowsAsync())
  {
    //Rows have been retrieved - process this "batch"...
    while (kg_rc.MoveNext())
    {
      //Get the current KnowledgeGraphRow
      using (var graph_row = kg_rc.Current)
      {
        //We are returning entities from this search
        var entity = graph_row[0] as KnowledgeGraphEntityValue;
        var entity_type = entity.GetTypeName();
        var record = new List<string>();
        //discover keys(aka "fields") dynamically via GetKeys
        foreach (var prop_name in entity.GetKeys())
        {
          var obj_val = entity[prop_name] ?? "null";
          record.Add(obj_val.ToString());
        }
        System.Diagnostics.Debug.WriteLine(
          $"{entity_type}[{e++}] " + string.Join(", ", record));
        //or use "Process a KnowledgeGraphRow Value" snippet
        //ProcessKnowledgeGraphRowValue(entity);
      }
    }
  }//WaitForRowsAsync
}//SubmitSearch
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3.2 or higher.
See Also