I have not yet had to do an identify but I have built a tool for selection by envelope. I just but a WPF button on page and on the Click event used the EnvelopSketchTool. There are other types of Sketch Tools- so I would look at those and see if any of those work better for what you need. when clicked- m_lastNavigatioMode = map1.CurrentNavigationMode;
map1.CurrentNavigationMode = ESRI.ArcGIS.Mobile.WPF.NavigationMode.None;
envelopeSketchTool = new EnvelopeSketchTool();
envelopeSketchTool.AttachToSketchGraphicLayer(selectionLayer); //selectionLayer is a MapGraphicLayer
envelopeSketchTool.SketchCompleted += doneSketch;
the on event firing private void doneSketch(object sender, EventArgs e)
{
Envelope env = envelopeSketchTool.Envelope;
if (envelopeSketchTool != null)
envelopeSketchTool.DetachFromSketchGraphicLayer();
//do something
}
Let me know if you come up with something else.