在.net中如何检查输入的名称是否为有效字符串？_symbolutilityservices.validatesymbolname-优快云博客

本文介绍了一种方法来检查用户提供的字符串是否适用于AutoCAD中的块名或图层名。通过使用SymbolUtilityServices.ValidateSymbolName()方法，可以有效验证名称是否符合规范。

How to check if a given string is a valid name for an item in a symbol table?

Issue

I want to check if a string provided by the user is suitable for a block name or for a layer name. Is there any function that can validate the string?

Solution

You are right, not every name is acceptable, for example, for a block. When creating a block in the AutoCAD UI, the user can get the following error message:

As you may know, there is a number of Symbol Tables in an dwg file, like Block table, Linetype table etc.

To check if a given string is a valid symbol table name or not, in ObjectARX you can use acdbSNValid() function.

AutoCAD .NET API provides the SymbolUtilityServices.ValidateSymbolName() for the same purpose. The method throws an exception when the name is invalid. Here is an example:

string[] names = { "lk3j4!@ #`$>%", // will cause an exception
                   "lk3j4!@ #$%" }; // will work fine
foreach (string s in names)
{
  try
  {
    // Validate the provided symbol table name
    SymbolUtilityServices.ValidateSymbolName( s, false);
 
    System.Windows.Forms.MessageBox.Show( s + " is a valid name." );
  }
  catch
  {
    // An exception has been thrown, indicating that
    //    the name is invalid
    System.Windows.Forms.MessageBox.Show( s +" is an invalid name.");
  }
} // foreach