Assigning null values
When assigning a null value to a property or parameter in the IDO protocol classes, the best practice is to use the IDONull.Value static property.
InvokeResponseData myMethodResponse; UpdateCollectionRequestData updateRequest; // pass NULL for the 3rd parameter myMethodResponse = this.Invoke("MyMethod", "test", 100, IDONull.Value); // set the Note property to NULL updateRequest.Items[0].Properties.Add("Note", IDONull.Value);