function DoGetSelect() {
        var ss = mxOcx.NewSelectionSet();
        var filter = mxOcx.NewResbuf();
        ss.CurrentSelect(filter);
        var i = 0;
        for (; i < ss.Count; i++) {
            var ent = ss.Item(i);
            if (ent.ObjectName == "McDbLine") {
                // 是个直线。
                var spt = ent.StartPoint;
                var ept = ent.EndPoint;
                alert(spt.x);
            }
            else if (ent.ObjectName == "McDbPolyline") {
                // 是个多义线.

                var j = 0;

                // 循环，得到端点坐标

                for (j = 0; j < ent.NumVerts; j++) {
                    var pt = ent.GetPointAt(j);
                    alert(pt.x);
                }
            }
        }
    }