public bool IsVersioningSupported()

public Geodatabase ConnectToVersion(Geodatabase geodatabase, string versionName)
{
  Geodatabase connectedVersion = null;

  if (geodatabase.IsVersioningSupported())
  {
    using (VersionManager versionManager = geodatabase.GetVersionManager())
    using (Version version = versionManager.GetVersion(versionName))
    {
      connectedVersion = version.Connect();
    }
  }
  return connectedVersion;
}

public 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 ReconcileDescription object
      //At 2.x - 
      //ReconcileDescription reconcileDescription = new ReconcileDescription(parentVersion);
      //reconcileDescription.ConflictResolutionMethod = ConflictResolutionMethod.Continue; // continue if conflicts are found
      //reconcileDescription.WithPost = true;

      //// Reconcile and post
      //ReconcileResult reconcileResult = currentVersion.Reconcile(reconcileDescription);

      // ReconcileResult.HasConflicts can be checked as-needed

      // 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
        currentVersion.Post(postOptions);
      }

    }
  }
}

public 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 ReconcileDescription object
      //At 2.x - 
      //ReconcileDescription reconcileDescription = new ReconcileDescription(parentVersion);
      //reconcileDescription.ConflictResolutionMethod = ConflictResolutionMethod.Continue; // continue if conflicts are found
      //reconcileDescription.WithPost = true;

      //// Reconcile and post
      //ReconcileResult reconcileResult = currentVersion.Reconcile(reconcileDescription);

      // ReconcileResult.HasConflicts can be checked as-needed

      // 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

      }

    }
  }
}