var prj = DlxApp.GetJob().GetProject("Example Sch");
if (!prj.IsValid())
  prj = DlxApp.GetJob().NewProject("Example Sch");
var doc = prj.GetDocument("Examples Sch", DlxApp.DOCTYPE_SCHEMATIC);
if (!doc.IsValid())
{
  doc = prj.NewDocument("Examples Sch", DlxApp.DOCTYPE_SCHEMATIC);
  doc.SetPageFormat("A4", false);
}
if (doc.IsValid() && doc.Activate())
{
  var page = doc.GetActivePage();
  if (page.IsValid())
  {
    var layer = page.GetLayerFromType(DlxApp.LAYERTYPE_DRAWING);
    if (layer.IsValid())
    {
      var p1 = new DlxPoint(50, 50);
      var p2 = new DlxPoint(100, 100);
      layer.DrawLine(p1, p2);
      var obj = layer.DrawAlignedDimension(p1, p2, 10);

      if (obj.GetValue()==DlxApp.DIMENSIONVALUE_AUTO)
      {
        obj.SetValue(12.5);
      }
    }
  }
}