CAD调用导角命令，并返回导角的圆弧对象

主要用到函数说明：

_DMxDrawX::SendStringToExecuteFun

把命令当着函数执行,可以传参数，详细说明如下：

参数	说明
IDispatch* pParam	命令参数，IMxDrawResbuf对象
pszExecute	命令名

c#代码实现如下：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

MxDrawEntity ent1 = (MxDrawEntity)axMxDrawX1.GetEntity("曲线1");                         if (ent1 == null)                                 return;               MxDrawEntity ent2 = (MxDrawEntity)axMxDrawX1.GetEntity("曲线2");                         if (ent2 == null)                                 return;               MxDrawResbuf param = new MxDrawResbuf();                         // 曲线1 id.             param.AddObjectId(ent1.ObjectID);                         // 曲线2 id.             param.AddObjectId(ent2.ObjectID);                         // 导角半径.             param.AddDoubleEx(10, 5001);                         // 调用导角命令，                         axMxDrawX1.SendStringToExecuteFun("Mx_Fillet", param);               MxDrawResbuf ret = (MxDrawResbuf)axMxDrawX1.Cal("Mx_GetRetArgs");                         if (ret.Count > 1)             {                                 // 导角成功.                 axMxDrawX1.TwinkeEnt(ret.AtObjectId(1));                       }