Question

I’m trying to create a sync between my mobile and database server. I am following this tutorial and it get ArgumentNullException Value can not be null.
Parameter name: ServerSyncProvider in sych() function.

Code

 private void Sync()
        {
            Cursor.Current = Cursors.WaitCursor;
            WebReference.NorthwindCacheSyncService svcProxy = new WebReference.NorthwindCacheSyncService();
            Microsoft.Synchronization.Data.ServerSyncProviderProxy syncProxy =
                new Microsoft.Synchronization.Data.ServerSyncProviderProxy(svcProxy);
            // Call SyncAgent.Synchronize() to initiate the synchronization process.
            // Synchronization only updates the local database, not your project's data source.
            NorthwindCacheSyncAgent syncAgent = new NorthwindCacheSyncAgent();
            Microsoft.Synchronization.Data.SyncStatistics syncStats = syncAgent.Synchronize();

            // TODO: Reload your project data source from the local database (for example, call the TableAdapter.Fill method).
            // Show synchronization statistics
            MessageBox.Show("Changes downloaded: " + syncStats.TotalChangesDownloaded.ToString()
                + "\r\nChanges Uploaded: " + syncStats.TotalChangesUploaded.ToString());

            Cursor.Current = Cursors.Default;

        }

Answer 1

As the error says “Value can not be null. Parameter name: ServerSyncProvider”

Means it is not initialized

You have missed one line of code inbetween

NorthwindCacheSyncAgent syncAgent = new NorthwindCacheSyncAgent();

syncAgent.RemoteProvider = syncProxy
Microsoft.Synchronization.Data.SyncStatistics syncStats = syncAgent.Synchronize();