ExternalDefinition

Public Class

The ExternalDefinition object adds properties specific to Autodesk Revit shared parameter definitions.

Inheritance Hierarchy

System.Object
Autodesk.Revit.DB.Definition
Autodesk.Revit.DB.ExternalDefinition

Namespace: Autodesk.Revit.DB

Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)

Syntax

public class ExternalDefinition : Definition,
  IDisposable

The ExternalDefinition type exposes the following members.

Properties

Name

Description

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Public Property

Description

The description of the parameter. The description will be used as tooltip in the Revit UI including in the properties palette.

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Public Property
GUID

Returns the GUID associated with the shared parameter definition.

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Public Property
HideWhenNoValue

Indicates whether this parameter should be hidden from the properties palette when it has no value.

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Public Property
IsValidObject

Specifies whether the .NET object represents a valid Revit entity.

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Public Property

Name

The user visible name for the parameter.
(Overrides

Definition.Name

)

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Public Property
OwnerGroup

Returns or change the group ID of the external parameter definition.

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Public Property
UserModifiable

Indicates whether the parameter can be modified by the user interface.

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Public Property
Visible

Indicates if the parameter is visible in the Autodesk Revit user interface.

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Methods

Name

Description

---

Public Method

Dispose

Releases all resources used by the ExternalDefinition

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Public Method

Equals

Determines whether the specified object is equal to the current object.
(Inherited from Object)

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Public Method
Code Example
GetDataType

Gets a ForgeTypeId identifying the data type describing values of the parameter.
(Inherited from Definition)

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Public Method

GetGroupTypeId

Returns the identifier of the parameter definition’s parameter group.
(Overrides

Definition.GetGroupTypeId.

)

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Public Method

GetHashCode

Serves as the default hash function.
(Inherited from Object)

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Public Method

GetType

Gets the Type of the current instance.
(Inherited from Object)

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Public Method

ToString

Returns a string that represents the current object.
(Inherited from Object)

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Remarks

The ExternalDefinition object can be created by a definition Group object from a shared parameters file. External parameter definition must belong to a Group which is nothing more than a collection of shared parameter definitions. The following process should be followed to add a parameter to an element: Open the shared parameters file, via the Application.OpenSharedParameterFile() method. Access an existing or create a new group, via the DefinitionFile.Groups property. Access an existing or create a new external parameter definition, via the DefinitionGroup.Definitions property. Create a new Binding object with the categories to which the parameter will be bound using an InstanceBinding or a TypeBinding object. Finally add the binding and definition to the document using the Document.ParameterBindings object.

Shared parameters added to elements are typically visible to interactive users. To add data to elements that is never visible to interactive users, use Extensible Storage to construct and populate the needed structured data.

Example

private void ReadEditExternalParam(DefinitionFile file)
{
    // get ExternalDefinition from shared parameter file
    DefinitionGroups myGroups = file.Groups;
    DefinitionGroup myGroup = myGroups.get_Item("MyGroup");
    if (myGroup != null)
    {
         ExternalDefinition myExtDef = myGroup.Definitions.get_Item("MyParam") as ExternalDefinition;
         if (myExtDef != null)
         {
             DefinitionGroup newGroup = myGroups.get_Item("AnotherGroup");
             if (newGroup != null)
             {
                 // change the OwnerGroup of the ExternalDefinition
                 myExtDef.OwnerGroup = newGroup;
             }
         }
    }
}