topic setting parameter value causes a transaction exception in Revit API Forum

setting parameter value causes a transaction exception

Anonymous — Tue, 23 Oct 2018 11:58:37 GMT

I am using revit 2016 and c#.

When my code runs to this part(existedParameter.Set(targetParamValue);), it throws an exception "attempts to modify the model out of a transaction."The method is nested in a transaction group.

private void SetFamilyInstParamsForSelectedElement(Document familyDoc, Element element, List<Dictionary<string, string>> selectedInstAttrList)
{
if (selectedInstAttrList == null || selectedInstAttrList.Count == 0) return;

foreach (Dictionary<string, string> dict in selectedInstAttrList)
{
string targetParam = dict["attrName"];
string targetParamType = dict["attrValueType"];
string targetParamValue = dict["valuelist"];

if (element.LookupParameter("CI_" + targetParam) != null)
{
using (Transaction trans = new Transaction(familyDoc, "set param value for CI_" + targetParam))
{
trans.Start();

Parameter existedParameter = element.LookupParameter("CI_" + targetParam);

if (!string.IsNullOrEmpty(targetParamValue) && targetParamValue != "--")
{
if (targetParamType == "0")
{
existedParameter.Set(targetParamValue);

}
else if (targetParamType == "1")
{
existedParameter.Set(Convert.ToDouble(targetParamValue));
}
}

trans.Commit();
}
}

Document familyDoc = document.EditFamily(fmiInst.Symbol.Family);
List<Dictionary<string, string>> selectedInstAttrList = form1.selectedInstAttrList;

string wuliaoleibie_code = fixedParams["wuliaoleibieBianhao"];
string wuliaoleibie_name = fixedParams["SmallType"];
string wuliaoleibie_ID = fixedParams["wuliaoleibieID"];
using (TransactionGroup transGroup = new TransactionGroup(document, "create parameters for the selected single element"))
{
transGroup.Start();
SetFamilySymbolStringParamForSingleElement(familyDoc, eleSymbol, "物料类别编号", wuliaoleibie_code);
SetFamilySymbolStringParamForSingleElement(familyDoc, eleSymbol, "物料类别名称", wuliaoleibie_name);
SetFamilySymbolStringParamForSingleElement(familyDoc, eleSymbol, "物料类别ID", wuliaoleibie_ID);
SetFamilyInstParamsForSelectedElement(familyDoc, targetElement, selectedInstAttrList);
transGroup.Assimilate();

}
familyDoc.LoadFamily(document, new projFamLoadOption());

Re: setting parameter value causes a transaction exception

BardiaJahan — Tue, 23 Oct 2018 12:39:25 GMT

Is targetElement in the familyDoc? - i.e. is familyDoc the same as targetElement.Document?

Your transaction is to edit the familyDoc and the changes you make are supposed to be on the elements that belong to that document. And I am not sure where that targetElement comes from.

Re: setting parameter value causes a transaction exception

Anonymous — Tue, 23 Oct 2018 12:50:21 GMT

The element is selected by the user:

Reference ref1 = uidoc.Selection.PickObject(Autodesk.Revit.UI.Selection.ObjectType.Element, "请选择单个元素");

Element targetElement = document.GetElement(ref1);

I try to upload my whole code file but I can not successfully submit my post unless I do not upload my file.

I tried to use FamilyManager.Set() method but I need to retrieve the parameter from my element based on the unique parameter name which cannot be converted to FamilyParameter that is required by the method. So I have to use parameter.set() method.

Re: setting parameter value causes a transaction exception

BardiaJahan — Tue, 23 Oct 2018 12:56:57 GMT

Instead of passing the document to your method why don't you retrieve it from the element - i.e. change it to this:

private void SetFamilyInstParamsForSelectedElement(Element element, List<Dictionary<string, string>> selectedInstAttrList)
        {
            Document document = element.Document;
            if (selectedInstAttrList == null || selectedInstAttrList.Count == 0) return;

            foreach (Dictionary<string, string> dict in selectedInstAttrList)
            {
                string targetParam = dict["attrName"];
                string targetParamType = dict["attrValueType"];
                string targetParamValue = dict["valuelist"];

                if (element.LookupParameter("CI_" + targetParam) != null)
                {
                    using (Transaction trans = new Transaction(document, "set param value for CI_" + targetParam))
                    {
                        trans.Start();

                        Parameter existedParameter = element.LookupParameter("CI_" + targetParam);

                        if (!string.IsNullOrEmpty(targetParamValue) && targetParamValue != "--")
                        {
                            if (targetParamType == "0")
                            {
                                existedParameter.Set(targetParamValue);

                            }
                            else if (targetParamType == "1")
                            {
                                existedParameter.Set(Convert.ToDouble(targetParamValue));
                            }
                        }

                        trans.Commit();
                    }
                }
            }
        }

Re: setting parameter value causes a transaction exception

Anonymous — Tue, 23 Oct 2018 13:31:15 GMT

Your answer seems right. Before I posted this question, I was struggling with document regenerating. However, I am going to sleep and I will try your solution tomorrow. If it worked, I will put an end to this post. Thanks for your reply!

Re: setting parameter value causes a transaction exception

Anonymous — Tue, 23 Oct 2018 13:57:05 GMT

And I have understand what you mean.

Document document = commandData.Application.ActiveUIDocument.Document;

UIDocument uidoc = commandData.Application.ActiveUIDocument;

Reference ref1 = uidoc.Selection.PickObject(Autodesk.Revit.UI.Selection.ObjectType.Element, "select an element");
Element targetElement = document.GetElement(ref1);

FamilyInstance fmiInst = targetElement as FamilyInstance;

Document familyDoc = document.EditFamily(fmiInst.Symbol.Family);

And the familyDoc is put into the transaction.