# GH_ParamViewer class Namespace: [Grasshopper.Kernel.Special](https://developer.rhino3d.com/api/gh1/namespace/grasshopper.kernel.special.md) ยท Assembly: [Grasshopper](https://developer.rhino3d.com/api/gh1/assembly/grasshopper.md) ```cs public class GH_ParamViewer : GH_Param, IGH_PreviewObject ``` ## Constructors - [GH_ParamViewer](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/ctor.md) ## Properties - [IGH_PreviewObject.ClippingBox](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/clippingbox.md) - [ComponentGuid](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/componentguid.md) - [DisplayGraph](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/displaygraph.md) - [Exposure](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/exposure.md) - [GraphicTree](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/graphictree.md) - [GraphicTreeArgs](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/graphictreeargs.md) - [IGH_PreviewObject.Hidden](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/hidden.md) - [Icon](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/icon.md) - [IconCapableUI](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/iconcapableui.md) - [IGH_PreviewObject.IsPreviewCapable](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/ispreviewcapable.md) - [Kind](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/kind.md) - [ScrollRatio](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/scrollratio.md) ## Methods - [AddSource](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/addsource.md): (2 overloads) - [AppendAdditionalMenuItems](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/appendadditionalmenuitems.md) - [ClearData](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/cleardata.md) - [CollectVolatileData_Custom](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/collectvolatiledata-custom.md) - [CollectVolatileData_FromSources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/collectvolatiledata-fromsources.md) - [CreateAttributes](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/createattributes.md) - [IGH_PreviewObject.DrawViewportMeshes](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/drawviewportmeshes.md) - [IGH_PreviewObject.DrawViewportWires](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/drawviewportwires.md) - [HtmlHelp_Source](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/htmlhelp-source.md) - [Menu_ToggleDisplayClicked](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/menu-toggledisplayclicked.md) - [Read](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/read.md) - [Write](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.special.gh-paramviewer/write.md) ## Inherited Members - From [GH_Param](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1.md): [m_data](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/m-data.md), [Access](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/access.md), [DataMapping](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/datamapping.md), [DataType](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/datatype.md), [HasProxySources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/hasproxysources.md), [InstanceDescription](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/instancedescription.md), [IsDataProvider](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/isdataprovider.md), [IsPrincipal](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/isprincipal.md), [Optional](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/optional.md), [ProcessorTime](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/processortime.md), [ProxySourceCount](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/proxysourcecount.md), [Recipients](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/recipients.md), [Reverse](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/reverse.md), [Simplify](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/simplify.md), [SourceCount](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/sourcecount.md), [Sources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/sources.md), [StateTags](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/statetags.md), [Type](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/type.md), [TypeName](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/typename.md), [VolatileData](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/volatiledata.md), [VolatileDataCount](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/volatiledatacount.md), [WireDisplay](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/wiredisplay.md), [AddVolatileData](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/addvolatiledata.md), [AddVolatileDataList](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/addvolatiledatalist.md), [AddVolatileDataTree](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/addvolatiledatatree.md), [Cast_Object](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/cast-object.md), [ClearProxySources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/clearproxysources.md), [CollectData](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/collectdata.md), [ComputeData](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/computedata.md), [ConnectNewObject](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/connectnewobject.md), [ConversionCallback](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/conversioncallback.md), [CreateProxySources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/createproxysources.md), [DependsOn](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/dependson.md), [ExpireDownStreamObjects](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/expiredownstreamobjects.md), [ExpireOwner](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/expireowner.md), [ExpireSolutionTopLevel](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/expiresolutiontoplevel.md), [Format](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/format.md), [InstantiateT](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/instantiatet.md), [IsolateObject](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/isolateobject.md), [Menu_AppendConnectRecipients](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendconnectrecipients.md), [Menu_AppendConnectSources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendconnectsources.md), [Menu_AppendConnectWires](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendconnectwires.md), [Menu_AppendDisconnectWires](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appenddisconnectwires.md), [Menu_AppendFlattenParameter](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendflattenparameter.md), [Menu_AppendGraftParameter](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendgraftparameter.md), [Menu_AppendPrincipalParameter](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendprincipalparameter.md), [Menu_AppendPublish](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendpublish.md), [Menu_AppendReverseParameter](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendreverseparameter.md), [Menu_AppendSimplifyParameter](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendsimplifyparameter.md), [Menu_AppendWireDisplay](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-appendwiredisplay.md), [Menu_ConnectOutputClicked](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/menu-connectoutputclicked.md), [OnVolatileDataCollected](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/onvolatiledatacollected.md), [PostProcessData](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/postprocessdata.md), [PreferredCast](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/preferredcast.md), [Preview_ComputeClippingBox](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/preview-computeclippingbox.md), [Preview_DrawMeshes](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/preview-drawmeshes.md), [Preview_DrawWires](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/preview-drawwires.md), [RegisterRemoteIDsUtil](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/registerremoteidsutil.md), [RelinkProxySources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/relinkproxysources.md), [RemoveAllSources](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/removeallsources.md), [RemoveEffects](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/removeeffects.md), [RemoveSource](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/removesource.md), [Render_AppendGeometry](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/render-appendgeometry.md), [ReplaceSource](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/replacesource.md), [SetPrincipal](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/setprincipal.md), [VolatileDataDescription](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-param-1/volatiledatadescription.md) - From [GH_ActiveObject](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject.md): [Locked](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/locked.md), [MutableNickName](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/mutablenickname.md), [Phase](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/phase.md), [RuntimeMessageLevel](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/runtimemessagelevel.md), [AddRuntimeMessage](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/addruntimemessage.md), [AppendMenuItems](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/appendmenuitems.md), [ClearRuntimeMessages](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/clearruntimemessages.md), [ExpireSolution](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/expiresolution.md), [Menu_AppendBakeItem](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/menu-appendbakeitem.md), [Menu_AppendEnableItem](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/menu-appendenableitem.md), [Menu_AppendPreviewItem](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/menu-appendpreviewitem.md), [Menu_AppendRuntimeMessages](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/menu-appendruntimemessages.md), [Menu_AppendWarningsAndErrors](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/menu-appendwarningsanderrors.md), [RegisterRemoteIDs](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/registerremoteids.md), [RuntimeMessages](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/runtimemessages.md), [SDKCompliancy](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-activeobject/sdkcompliancy.md) - From [GH_DocumentObject](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject.md): [m_attributes](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/m-attributes.md), [Attributes](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/attributes.md), [IconDisplayMode](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/icondisplaymode.md), [Icon_24x24](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/icon-24x24.md), [Icon_24x24_Locked](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/icon-24x24-locked.md), [Internal_Icon_24x24](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/internal-icon-24x24.md), [Obsolete](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/obsolete.md), [AttributesChanged](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/attributeschanged.md), [DisplayExpired](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/displayexpired.md), [ObjectChanged](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/objectchanged.md), [PingDocument](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/pingdocument.md), [PreviewExpired](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/previewexpired.md), [SolutionExpired](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/solutionexpired.md), [AddedToDocument](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/addedtodocument.md), [DestroyIconCache](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/destroyiconcache.md), [DocumentContextChanged](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/documentcontextchanged.md), [ExpirePreview](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/expirepreview.md), [GetValue](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/getvalue.md), [Menu_AppendObjectHelp](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/menu-appendobjecthelp.md), [Menu_AppendObjectName](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/menu-appendobjectname.md), [Menu_AppendObjectNameEx](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/menu-appendobjectnameex.md), [MovedBetweenDocuments](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/movedbetweendocuments.md), [OnAttributesChanged](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/onattributeschanged.md), [OnDisplayExpired](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/ondisplayexpired.md), [OnObjectChanged](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/onobjectchanged.md), [OnPingDocument](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/onpingdocument.md), [OnPreviewExpired](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/onpreviewexpired.md), [OnSolutionExpired](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/onsolutionexpired.md), [RecordUndoEvent](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/recordundoevent.md), [RemovedFromDocument](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/removedfromdocument.md), [SetIconOverride](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/seticonoverride.md), [SetValue](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/setvalue.md), [TriggerAutoSave](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/triggerautosave.md), [ValuesChanged](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-documentobject/valueschanged.md) - From [GH_InstanceDescription](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription.md): [Category](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/category.md), [Description](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/description.md), [HasCategory](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/hascategory.md), [HasSubCategory](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/hassubcategory.md), [InstanceGuid](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/instanceguid.md), [Keywords](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/keywords.md), [Name](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/name.md), [NickName](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/nickname.md), [SubCategory](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/subcategory.md), [CopyFrom](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/copyfrom.md), [NewInstanceGuid](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/newinstanceguid.md), [ReadFull](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/readfull.md), [WriteFull](https://developer.rhino3d.com/api/gh1/type/grasshopper.kernel.gh-instancedescription/writefull.md)