[CommandMethod("SL4")]
public void ShowMainForm()
{
StartPictureForm_ startPictureForm = new StartPictureForm_();
if (startPictureForm.ShowDialog() == DialogResult.Cancel)
{
SectionManagerMainForm form = new SectionManagerMainForm();
Autodesk.AutoCAD.ApplicationServices.Application.ShowModelessDialog(form); // 非模态对话框;
}
}