Creates a new arc length dimension object using the default dimension type. 
   Namespace:   Autodesk.Revit.Creation  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
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| Visual Basic | 
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| Visual C++ | 
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Parameters
- view
 -  Type:  Autodesk.Revit.DB View  
The view in which the dimension is to be visible. 
- arc
 -  Type:  Autodesk.Revit.DB Arc  
The extension arc of the dimension. 
- arcRef
 -  Type:  Autodesk.Revit.DB Reference  
Geometric reference of the arc to which the dimension is to be bound. This reference must be parallel to the extension arc. 
- firstRef
 -  Type:  Autodesk.Revit.DB Reference  
The first geometric reference to which the dimension is to be bound. This reference must intersect the arcRef reference. 
- secondRef
 -  Type:  Autodesk.Revit.DB Reference  
The second geometric reference to which the dimension is to be bound. This reference must intersect the arcRef reference. 
Return Value
If creation was successful the new arc length dimension is returned, otherwise an exception with failure information will be thrown.Remarks
 The currently user set default style is used for the created dimension. 
 Examples
public Dimension CreateArcDimension(Document document, SketchPlane sketchPlane)
{
    Autodesk.Revit.Creation.Application appCreate = document.Application.Create;
    Line gLine1 = Line.CreateBound(new XYZ(0, 2, 0), new XYZ(2, 2, 0));
    Line gLine2 = Line.CreateBound(new XYZ(0, 2, 0), new XYZ(2, 4, 0));
    Arc arctoDim = Arc.Create(new XYZ(1, 2, 0), new XYZ(-1, 2, 0), new XYZ(0, 3, 0));
    Arc arcofDim = Arc.Create(new XYZ(0, 3, 0), new XYZ(1, 2, 0), new XYZ(0.8, 2.8, 0));
    Autodesk.Revit.Creation.FamilyItemFactory creationFamily = document.FamilyCreate;
    ModelCurve modelCurve1 = creationFamily.NewModelCurve(gLine1, sketchPlane);
    ModelCurve modelCurve2 = creationFamily.NewModelCurve(gLine2, sketchPlane);
    ModelCurve modelCurve3 = creationFamily.NewModelCurve(arctoDim, sketchPlane);
    //get their reference
    Reference ref1 = modelCurve1.GeometryCurve.Reference;
    Reference ref2 = modelCurve2.GeometryCurve.Reference;
    Reference arcRef = modelCurve3.GeometryCurve.Reference;
    Dimension newArcDim = creationFamily.NewArcLengthDimension(document.ActiveView, arcofDim, arcRef, ref1, ref2);
    if (newArcDim == null)
    {
        throw new Exception("Failed to create new arc length dimension.");
    }
    return newArcDim;
} Public Function CreateArcDimension(document As Document, sketchPlane As SketchPlane) As Dimension
    Dim appCreate As Autodesk.Revit.Creation.Application = document.Application.Create
    Dim gLine1 As Line = Line.CreateBound(New XYZ(0, 2, 0), New XYZ(2, 2, 0))
    Dim gLine2 As Line = Line.CreateBound(New XYZ(0, 2, 0), New XYZ(2, 4, 0))
    Dim arctoDim As Arc = Arc.Create(New XYZ(1, 2, 0), New XYZ(-1, 2, 0), New XYZ(0, 3, 0))
    Dim arcofDim As Arc = Arc.Create(New XYZ(0, 3, 0), New XYZ(1, 2, 0), New XYZ(0.8, 2.8, 0))
    Dim creationFamily As Autodesk.Revit.Creation.FamilyItemFactory = document.FamilyCreate
    Dim modelCurve1 As ModelCurve = creationFamily.NewModelCurve(gLine1, sketchPlane)
    Dim modelCurve2 As ModelCurve = creationFamily.NewModelCurve(gLine2, sketchPlane)
    Dim modelCurve3 As ModelCurve = creationFamily.NewModelCurve(arctoDim, sketchPlane)
    'get their reference
    Dim ref1 As Reference = modelCurve1.GeometryCurve.Reference
    Dim ref2 As Reference = modelCurve2.GeometryCurve.Reference
    Dim arcRef As Reference = modelCurve3.GeometryCurve.Reference
    Dim newArcDim As Dimension = creationFamily.NewArcLengthDimension(document.ActiveView, arcofDim, arcRef, ref1, ref2)
    If newArcDim Is Nothing Then
        Throw New Exception("Failed to create new arc length dimension.")
    End If
    Return newArcDim
End Function Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions ArgumentNullException | Thrown when any input argument is a null reference ( Nothing in Visual Basic) . | 
| Autodesk.Revit.Exceptions ArgumentException | Thrown when the argument arcRef/ref1/ref2 is invalid. | 
| Autodesk.Revit.Exceptions InvalidOperationException | Thrown when the creation failed. |