public static void SendACommandToAutoCAD(string command)
{
	MgdAcDocument doc = MgdApplication.DocumentManager.MdiActiveDocument;
	if(doc == null)
	{
		MessageBox.Show("当前无活动文档，请新建或切换至活动文档后再执行命令", "无法获取活动文档", MessageBoxButtons.OK, MessageBoxIcon.Stop);
		return;
	}
	// 根据是否有命令运行决定esc的数量
	string esc = "";
	string cmds = (string)MgdApplication.GetSystemVariable("CMDNAMES");
	if (cmds.Length > 0)
	{
		int cmdNum = cmds.Split(new char[] { '\'' }).Length;
		for (int i = 0; i < cmdNum; i++)
		{
			esc += '\x03';
		}
	}
	doc.SendStringToExecute(esc + "_." + command + " ", true, false, true);
}