If I create an instance of Esri.ArcGISRuntime.UI.Graphic and add an attribute to it, in which the value of the attribute is a member of an enum, the graphic will not be successfully added to the graphics collection of an overlay. It fails silently and and I'll see this in the output window at debug time:
Exception thrown: 'System.NotSupportedException' in Esri.ArcGISRuntime.dll
Error: 'Specified method is not supported.'
Code that doesn't work:
var sketchGraphic = new Esri.ArcGISRuntime.UI.Graphic(geometry, symbol);
sketchGraphic.Attributes.Add(_adHocGraphicTypeAttributeName, AdHocGraphicTypeEnum.UserSketch);
sketchOverlay.Graphics.Add(sketchGraphic);
Code that does work:
var sketchGraphic = new Esri.ArcGISRuntime.UI.Graphic(geometry, symbol);
sketchGraphic.Attributes.Add(_adHocGraphicTypeAttributeName, 1);
sketchOverlay.Graphics.Add(sketchGraphic);
The enum above is defined as:
public enum AdHocGraphicTypeEnum
{
Unknown = 0,
UserSketch = 1,
Buffer = 2
}