ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data Namespace / Version Class / Reconcile Method / Reconcile(ReconcileOptions) Method
If ReconcileOptions.TargetVersion is not specified in reconcileOptions, then the target version is the Default version.
Example Version

Reconcile(ReconcileOptions) Method
Reconciles this version against a target version specified in reconcileOptions. This method must be called on the MCT. Use QueuedTask.Run.
Syntax

Parameters

reconcileOptions
If ReconcileOptions.TargetVersion is not specified in reconcileOptions, then the target version is the Default version.

Return Value

An instance of ReconcileResult indicating the results of the operation.
Exceptions
ExceptionDescription
reconcileOptions is null.

This operation is not supported in client-server mode because the data store supports multi-branch versioning.

-or-

Multi-branch versioning does not support a ConflictResolutionType that favors the target version.

Reconcile cannot be performed in an active edit session.
A geodatabase-related exception has occurred.
This method or property must be called within the lambda passed to QueuedTask.Run
Example
Illustrate version conflict information from a reconcile operation
public void GetVersionConflictsInfoInUpdateDeleteType(ServiceConnectionProperties featureServiceConnectionProperties, string featureClassName)
{
    // To illustrate the conflict between versions,
    // the feature is updated in the child version and deleted in the parent version.

    long featureObjectIDForEdit = Int64.MinValue;

    // Get branch versioned service
    using (Geodatabase fsGeodatabase = new Geodatabase(featureServiceConnectionProperties))
    using (VersionManager versionManager = fsGeodatabase.GetVersionManager())
    using (Version defaultVersion = versionManager.GetDefaultVersion())
    using (Geodatabase defaultGeodatabase = defaultVersion.Connect())
    using (FeatureClass defaultFeatureClass = defaultGeodatabase.OpenDataset<FeatureClass>(featureClassName))
    using (FeatureClassDefinition defaultFeatureClassDefinition = defaultFeatureClass.GetDefinition())
    {
        // Create a feature in the default version to edit in a branch
        defaultGeodatabase.ApplyEdits(() =>
        {
            using (RowBuffer rowBuffer = defaultFeatureClass.CreateRowBuffer())
            {
                rowBuffer["NAME"] = "Loblolly Pine";
                rowBuffer["TREEAGE"] = 1;
                rowBuffer[defaultFeatureClassDefinition.GetShapeField()] = new MapPointBuilderEx(new Coordinate2D(1, 1),
          SpatialReferenceBuilder.CreateSpatialReference(4152, 0)).ToGeometry();

                using (Feature feature = defaultFeatureClass.CreateRow(rowBuffer))
                {
                    featureObjectIDForEdit = feature.GetObjectID();
                }
            }
        });

        // Add newly created feature in the filter
        QueryFilter queryFilter = new QueryFilter { ObjectIDs = new List<long> { featureObjectIDForEdit } };

        // Create a branch version
        VersionDescription versionDescription = new VersionDescription("UpdateDeleteConflictType",
          "Update-Delete version conflict type", VersionAccessType.Private);

        // Edit the feature in the branch 
        using (Version editVersion = versionManager.CreateVersion(versionDescription))
        using (Geodatabase branchGeodatabase = editVersion.Connect())
        using (FeatureClass featureClass = branchGeodatabase.OpenDataset<FeatureClass>(featureClassName))
        using (RowCursor rowCursor = featureClass.Search(queryFilter, false))
        {
            branchGeodatabase.ApplyEdits(() =>
            {
                while (rowCursor.MoveNext())
                {
                    using (Row row = rowCursor.Current)
                    {
                        row["TREEAGE"] = 100;
                        row["NAME"] = $"{row["Name"]}_EditInBranch";
                        row.Store();
                    }
                }
            });

            // Delete the feature from the default version
            defaultFeatureClass.DeleteRows(queryFilter);

            // Reconcile options
            ReconcileOptions reconcileOptions = new ReconcileOptions(defaultVersion)
            {
                ConflictResolutionType = ConflictResolutionType.FavorEditVersion,
                ConflictDetectionType = ConflictDetectionType.ByRow,
                ConflictResolutionMethod = ConflictResolutionMethod.Continue
            };

            // Reconcile with default
            ReconcileResult reconcileResult = editVersion.Reconcile(reconcileOptions);

            // Check for conflicts
            bool hasConflictsReconcileResults = reconcileResult.HasConflicts;
            bool hasConflictsAfterReconcile = editVersion.HasConflicts();

            // Fetch conflicts
            IReadOnlyList<Conflict> conflictsAfterReconcile = editVersion.GetConflicts();

            // Iterate conflicts
            foreach (Conflict conflict in conflictsAfterReconcile)
            {
                // Object ID of row where conflict occurs
                long objectId = conflict.ObjectID;

                ConflictType conflictType = conflict.ConflictType;

                IReadOnlyList<FieldValue> ancestorVersionValues = conflict.AncestorVersionValues;
                object nameAncestor = ancestorVersionValues.FirstOrDefault(f => f.FieldName.Contains("NAME")).Value;
                object treeAgeAncestor = ancestorVersionValues.FirstOrDefault(f => f.FieldName.Contains("TREEAGE")).Value;

                IReadOnlyList<FieldValue> childVersionValues = conflict.ChildVersionValues;
                object nameChild = childVersionValues.FirstOrDefault(f => f.FieldName.Contains("NAME")).Value;
                object treeAgeChild = childVersionValues.FirstOrDefault(f => f.FieldName.Contains("TREEAGE")).Value;

                IReadOnlyList<FieldValue> parentVersionValues = conflict.ParentVersionValues;

                IReadOnlyList<Field> originalFields = defaultFeatureClassDefinition.GetFields();

                string datasetName = conflict.DatasetName;
            }
        }
    }
}
Reconciling and Posting a Version with its Parent in separate edit sessions
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);
            }

        }
    }
}
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also