在NX8.5中使用C#编辑表达式中有个坑,part.Expressions.Edit该方法鲁棒性很差,当表达式有错时也能编辑成功(手动在NX中增加错误表达式会有弹框,无法创建,而该方法却可以,疑是bug),建议使用表达式对象的RightHandSide属性进行设置。错误的表达式导致对象在保存或者设为显示部件、工作部件时,NX报“Update undo happened”错误!
如下图:
一个简单的例子:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using NXOpen; using NXOpen.Utilities; using NXOpen.UF; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { Session theSession = Session.GetSession(); UFSession theUfSession = UFSession.GetUFSession(); UFUi theUFUi = theUfSession.Ui; string path = @"D: est model\_asm1.prt"; NXOpen.Tag obj = NXOpen.Tag.Null; UFPart.LoadStatus LoadStatus; theUfSession.Part.Open(path, out obj, out LoadStatus); NXOpen.Part part = theSession.Parts.Display; try { foreach (Expression p in part.Expressions) { if ("a" == p.Name) { p.RightHandSide = "4"; //part.Expressions.Edit(p, "ab*cd*ef+5"); p.EditComment("测试"); } } //Expression exp = part.Expressions.Create("a=1"); } catch(Exception ex) { Console.WriteLine(ex.Message); } theUfSession.Part.Save(); theUfSession.Part.CloseAll(); } } }
创建表达式(part.Expressions.Create)方法和编辑表达式(RightHandSide)属性,当表达式错误时会抛出异常,使用try catch根据这点判断表达式是否正确。