在Revit API中加载族可以使用Doc.LoadFamily方法，传入要加载的族文件路径名，但是这种方式有一种缺点，就是如果族文件在当前工程中没有加载的话则返回成功，如果已经加载过，则返回失败，也就是拿不到FamilySymbol实例，而根据族生成实例图元又需要这个FamilySymbol。网上看到有些帖子说可以传入IFamilyLoadOptions实例就可以，但是笔者多次尝试，该方法均没有成功，始终返回失败，无奈放弃这种方法，改为在当前工程中查找该族是否加载过，如果加载则直接返回FamilySymbol实例，否则加载族文件，下面贴出代码。
该代码在Revit 2016 + VS2013下调试通过：
public class CreateFamilyInstance : IExternalCommand
{
private class FamilyLoadOptions : IFamilyLoadOptions
{
public bool OnFamilyFound(bool familyInUse, out bool overwriteParameterValues)
{
overwriteParameterValues = true;
return true;
} public bool OnSharedFamilyFound(Family sharedFamily, bool familyInUse, out FamilySource source, out bool overwriteParameterValues)
{
source = FamilySource.Family;
overwriteParameterValues = true;
return true;
}
} private FamilySymbol FindFamilySymbol(Document rvtDoc, string familyName, string symbolName)
{
FilteredElementCollector collector = new FilteredElementCollector(rvtDoc);
FilteredElementIterator itr = collector.OfClass(typeof(Family)).GetElementIterator();
itr.Reset();
while (itr.MoveNext())
{
Autodesk.Revit.DB.Element elem = (Autodesk.Revit.DB.Element)itr.Current;
if (elem.GetType() == typeof(Autodesk.Revit.DB.Family))
{
if (elem.Name == familyName)
{
Autodesk.Revit.DB.Family family = (Autodesk.Revit.DB.Family)elem;
foreach (Autodesk.Revit.DB.ElementId symbolId in family.GetFamilySymbolIds())
{
Autodesk.Revit.DB.FamilySymbol symbol = (Autodesk.Revit.DB.FamilySymbol)rvtDoc.GetElement(symbolId);
if (symbol.Name == symbolName)
{
return symbol;
}
}
}
}
}
return null;
} public Autodesk.Revit.UI.Result Execute(ExternalCommandData cmdData,
ref string message, Autodesk.Revit.DB.ElementSet elements)
{
UIApplication app = cmdData.Application;
Document doc = app.ActiveUIDocument.Document;
Transaction trans = new Transaction(doc, "ExComm");
trans.Start();
Family fs = null;
FamilySymbol symbol = null;
doc.LoadFamily(@"C:\\ProgramData\\Autodesk\\RVT 2016\\Libraries\\China\\结构\\柱\\混凝土\\混凝土柱-T形.rfa",
new FamilyLoadOptions(), out fs);
if (fs != null)
{
foreach (ElementId symbolId in fs.GetFamilySymbolIds())
{
Element elem = doc.GetElement(symbolId);
if (null != elem)
{
symbol = elem as FamilySymbol;
if (null != symbol)
{
TaskDialog.Show("Info", symbol.Name);
TaskDialog.Show("Info", symbol.FamilyName); break;
}
}
}
}
else
{
symbol = FindFamilySymbol(doc, "混凝土柱-T形", "标准");
if (null != symbol)
{
TaskDialog.Show("Info", symbol.Name);
TaskDialog.Show("Info", symbol.FamilyName);
}
} if (null != symbol)
{
if (!symbol.IsActive)
symbol.Activate();
XYZ point = new XYZ(10, 10, 10);
//创建族实例
FamilyInstance fi = doc.Create.NewFamilyInstance(point, symbol,
Autodesk.Revit.DB.Structure.StructuralType.Column);
}
else
{
TaskDialog.Show("erorr", "FamilySymbol为空");
}
trans.Commit(); return Autodesk.Revit.UI.Result.Succeeded;
}
}