Cannot center IActiveView at IPoint in C#.NET add in

Question

I'm testing a simple portion of my add in and can't get it to center/pan to a specified point, I've included what is currently in my OnClick() method. No errors appear it just refreshes and nothing happens (10.1 SP1, C#.NET VS 2010).

IMxDocument mxdoc = ArcMap.Application.Document as IMxDocument;
IActiveView actView = mxdoc.FocusMap as IActiveView;
IPageLayout pLayout = actView as IPageLayout;
ISpatialReferenceFactory srFactory = new SpatialReferenceEnvironmentClass();
int gcsCode = (int)esriSRGeoCSType.esriSRGeoCS_NAD1983;
ISpatialReference spatRef = srFactory.CreateGeographicCoordinateSystem(gcsCode);

try
{
    IPoint point = new PointClass();
    double xCoord = 33.217918;
    double yCoord = -98.158749;
    point.PutCoords(xCoord, yCoord);
    point.Project(spatRef);
    actView.Extent.CenterAt(point);
    actView.Refresh();
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

Answer 1

There's a few problems here. First IMxDocument.FocusMap is read only, you can't change the extent from here, use IMxDocument.ActiveView instead.

Instead of projecting your point (point.Project(spatRef);) you need to set it by using IPoint.SpatialReference (inheritied from IGeometry class): point.SpatialReference = spatRef;

I have found it better to pan an envelope rather than trying to modify with CenterAt:

IEvelope pEnv = mxdoc.ActiveView.Extent;
pEnv.CenterAt(point);
mxdoc.ActiveView.Extent = pEnv;