Opening

private void Getinfo_Opening(Opening opening)
{
    string message = "Opening:";

    //get the host element of this opening
    message += "\nThe id of the opening's host element is : " + opening.Host.Id.ToString();

    //get the information whether the opening has a rect boundary
    //If the opening has a rect boundary, we can get the geometry information from BoundaryRect property.
    //Otherwise we should get the geometry information from BoundaryCurves property
    if (opening.IsRectBoundary)
    {
        message += "\nThe opening has a rectangular boundary.";
        //array contains two XYZ objects: the max and min coords of boundary
        IList<XYZ> boundaryRect = opening.BoundaryRect;

        //get the coordinate value of the min coordinate point
        XYZ point = opening.BoundaryRect[0];
        message += "\nMin coordinate point:(" + point.X + ", "
                                + point.Y + ", " + point.Z + ")";

        //get the coordinate value of the Max coordinate point
        point = opening.BoundaryRect[1];
        message += "\nMax coordinate point: (" + point.X + ", "
                                + point.Y + ", " + point.Z + ")";
    }
    else
    {
        message += "\nThe opening doesn't have a rectangular boundary.";
        // Get curve number
        int curves = opening.BoundaryCurves.Size;
        message += "\nNumber of curves is : " + curves;
        for (int i = 0; i < curves; i++)
        {
            Autodesk.Revit.DB.Curve curve = opening.BoundaryCurves.get_Item(i);
            // Get curve start point
            message += "\nCurve start point: " + XYZToString(curve.GetEndPoint(0));
            // Get curve end point
            message += "; Curve end point: " + XYZToString(curve.GetEndPoint(1));
        }
    }
    TaskDialog.Show("Revit",message);
}

// output the point's three coordinates
string XYZToString(XYZ point)
{
    return "(" + point.X + ", " + point.Y + ", " + point.Z + ")";
}