public sealed class ReconcileOptions 

{
  // Must be called within QueuedTask.Run
  void ReconcileAndPost(Geodatabase geodatabase)
  {
    // Get a reference to our version and our parent
    if (geodatabase.IsVersioningSupported())
    {
      using (VersionManager versionManager = geodatabase.GetVersionManager())
      using (Version currentVersion = versionManager.GetCurrentVersion())
      using (Version parentVersion = currentVersion.GetParent())
      {
        // Create a ReconcileOptions object
        ReconcileOptions reconcileOptions = new ReconcileOptions(parentVersion);
        reconcileOptions.ConflictResolutionMethod = ConflictResolutionMethod.Continue; // continue if conflicts are found
        reconcileOptions.ConflictDetectionType = ConflictDetectionType.ByRow; //Default
        reconcileOptions.ConflictResolutionType = ConflictResolutionType.FavorTargetVersion; //or FavorEditVersion

        // Reconcile
        ReconcileResult reconcileResult = currentVersion.Reconcile(reconcileOptions);
        if (!reconcileResult.HasConflicts)
        {
          //No conflicts, perform the post
          PostOptions postOptions = new PostOptions(parentVersion);
          //var postOptions = new PostOptions(); for default version
          postOptions.ServiceSynchronizationType = ServiceSynchronizationType.Synchronous; //Default

          // Post - Deprecated since Pro SDK 3.6 / Enterprise 12.0 . Use Reconcile(reconcileOptions, postOptions) instead.
          // currentVersion.Post(postOptions);

          currentVersion.Reconcile(reconcileOptions, postOptions);
        }
      }
    }
  }
}

{
  // Must be called within QueuedTask.Run
  void ReconcileAndPost2(Geodatabase geodatabase)
  {
    // Get a reference to our version and our parent
    if (geodatabase.IsVersioningSupported())
    {
      using (VersionManager versionManager = geodatabase.GetVersionManager())
      using (Version currentVersion = versionManager.GetCurrentVersion())
      using (Version parentVersion = currentVersion.GetParent())
      {
        // Create a ReconcileOptions object
        ReconcileOptions reconcileOptions = new ReconcileOptions(parentVersion);
        reconcileOptions.ConflictResolutionMethod = ConflictResolutionMethod.Continue; // continue if conflicts are found
        reconcileOptions.ConflictDetectionType = ConflictDetectionType.ByRow; //Default
        reconcileOptions.ConflictResolutionType = ConflictResolutionType.FavorTargetVersion; //or FavorEditVersion

        PostOptions postOptions = new PostOptions(parentVersion);
        //var postOptions = new PostOptions(); for default version
        postOptions.ServiceSynchronizationType = ServiceSynchronizationType.Synchronous; //Default

        // Reconcile
        ReconcileResult reconcileResult = currentVersion.Reconcile(reconcileOptions, postOptions);
        if (reconcileResult.HasConflicts)
        {
          //TODO resolve conflicts
        }
      }
    }
  }
}

{
  // Must be called within QueuedTask.Run
  void PartialPostingSnippet(Version designVersion, FeatureClass supportStructureFeatureClass, List<long> deletedSupportStructureObjectIDs)
  {
    // Partial posting allows developers to post a subset of changes made in a version.
    // One sample use case is an electric utility that uses a version to design the facilities in
    // a new housing subdivision. At some point in the process, one block of new houses have been
    // completed, while the rest of the subdivision remains unbuilt.  Partial posting allows the user
    // to post the completed work, while leaving not yet constructed features in the version to be
    // posted later. Partial posting requires a branch-versioned feature service using ArcGIS
    // Enterprise 10.9 and higher

    // Specify a set of features that were constructed
    QueryFilter constructedFilter = new QueryFilter()
    {
      WhereClause = "ConstructedStatus = 'True'"
    };
    // This selection represents the inserts and updates to the support
    // structure feature class that we wish to post
    using (Selection constructedSupportStructures = supportStructureFeatureClass.Select(constructedFilter, SelectionType.ObjectID,
             SelectionOption.Normal))
    {
      // Specifying which feature deletions you wish to post is slightly trickier, since you cannot issue
      // a query to fetch a set of deleted features Instead, a list of ObjectIDs must be used
      using (Selection deletedSupportStructures = supportStructureFeatureClass.Select(null, SelectionType.ObjectID, SelectionOption.Empty))
      {
        deletedSupportStructures.Add(deletedSupportStructureObjectIDs); //deletedSupportStructureObjectIDs is defined as List<long>

        // Perform the reconcile with partial post
        ReconcileOptions reconcileOptions = new ReconcileOptions(); // Reconcile against Default
        reconcileOptions.ConflictDetectionType = ConflictDetectionType.ByColumn;
        reconcileOptions.ConflictResolutionMethod = ConflictResolutionMethod.Continue;
        reconcileOptions.ConflictResolutionType = ConflictResolutionType.FavorEditVersion;

        /*
        PostOptions postOptions = new PostOptions(); 
        
        // PartialPostSelections - Deprecated since Pro SDK 3.7. Use PartialPostOptions instead. 
        postOptions.PartialPostSelections = new List<Selection>()
          {
            constructedSupportStructures, deletedSupportStructures
          };
        postOptions.ServiceSynchronizationType = ServiceSynchronizationType.Synchronous;
        */

        PartialPostOptions partialPostOptions = new PartialPostOptions(); // Partial post against the Default
        partialPostOptions.Selections = new List<Selection>()
        {
          constructedSupportStructures, deletedSupportStructures
        };
        partialPostOptions.ServiceSynchronizationType = ServiceSynchronizationType.Synchronous;

        ReconcileResult reconcileResult = designVersion.Reconcile(reconcileOptions, partialPostOptions);

        // Use the reconcileResult ...
      }
    }
  }
}