BaseTool を使用したフラッシュ

'フィーチャの取得
Dim pPoint As IPoint = m_hookHelper.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(X, Y)

Dim pIdentify As IIdentify = CType(pCountryFeatureLayer, IIdentify)
Dim pArray As IArray = pIdentify.Identify(CType(pPoint, IGeometry))
If pArray Is Nothing Then
    MessageBox.Show("Country フィーチャをクリックしてください。")
    Return
End If
Dim pIdentiryObj As IIdentifyObj = CType(pArray.Element(0), IIdentifyObj)
'pIdentiryObj.Flash(m_hookHelper.ActiveView.ScreenDisplay)         'フィーチャのフラッシュ

Dim pRowIdentifyObject As IRowIdentifyObject = CType(pIdentiryObj, IRowIdentifyObject)
Dim pCountryFeature As IFeature = CType(pRowIdentifyObject.Row, IFeature)

Dim pHookActions As IHookActions = CType(m_hookHelper, IHookActions)
pHookActions.DoAction(pCountryFeature.ShapeCopy, esriHookActions.esriHookActionsFlash)