CAD二开中，经常会用到用户交互功能，常见的方法如下：

GetKeyword 方法提示用户在 AutoCAD 命令提示下输入关键字,GetString 方法提示用户在 AutoCAD 命令提示下输入字符串。两者就有区别又有相似处，getkeyword只允许用户输入指定的字符。

GetKeyword 方法：AllowNone 属性为False强制用户输入关键字，而禁止输入 NULL（按回车键）。Keywords 用于添加有效的关键字列表。

GetString 方法：该方法接收两个参数。PromptStringOptions 对象允许控制用户输入以及怎样显示提示信息。PromptStringOptions 对象的 AllowSpaces 属性控制是否允许输入空格。如果为 False ，按空格键将中止用户输入。

getkeyword案例如下：

 

附代码： 

using AcTools;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using System;
using System.Collections.Generic;
using System.Linq;namespace Acdemo
{public  class Acdemo{[CommandMethod("xx")]public void ACDE(){Document acDoc = Application.DocumentManager.MdiActiveDocument;Database db = HostApplicationServices.WorkingDatabase;Line line = new Line(Point3d.Origin, new Point3d(100, 100, 0));Line line1 = new Line(Point3d.Origin, new Point3d(50, 200, 0));//db.AddEntityToModeSpace(line);PromptKeywordOptions pKeyOpts = new PromptKeywordOptions("");pKeyOpts.Message = "\nEnter an option ";pKeyOpts.Keywords.Add("Line");pKeyOpts.Keywords.Add("Circle");pKeyOpts.Keywords.Add("Arc");pKeyOpts.AllowNone = false;PromptResult pKeyRes = acDoc.Editor.GetKeywords(pKeyOpts);//Application.ShowAlertDialog("Entered keyword: " +//                            pKeyRes.StringResult);//if (pKeyRes.StringResult == "Line")//{//    db.AddLineToModeSpace(new Point3d(), new Point3d(100, 100, 0));//}switch (pKeyRes.StringResult){case "Line":Database db1 = HostApplicationServices.WorkingDatabase;db1.AddEntityToModeSpace(line1);break;case "Circle":db.AddCircleModeSpace(new Point3d(), 100);break;case "Arc":db.AddArcToModeSpace(new Point3d(0,0,0), new Point3d(500, 100, 0), new Point3d(200, 200, 0));break;}}}
}

getstring用法：

using AcTools;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using System;
using System.Collections.Generic;
using System.Linq;namespace Acdemo
{public  class Acdemo{public static void GetStringFromUser(string message){Document acDoc = Application.DocumentManager.MdiActiveDocument;PromptStringOptions pStrOpts = new PromptStringOptions("\nEnter your name: ");pStrOpts.AllowSpaces = true;PromptResult pStrRes = acDoc.Editor.GetString(pStrOpts);Application.ShowAlertDialog(message +  "\nThe name entered was: " +pStrRes.StringResult);}[CommandMethod("xx")]public void ACDE(){  GetStringFromUser("Hello,world !");}}
}