AutoCAD二次开发（.Net）之获取LSP变量的值

[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("accore.dll", EntryPoint = "acedPutSym",
CharSet = CharSet.Unicode, CallingConvention = CallingConvention.Cdecl)]
extern static private int acedPutSym(string args, IntPtr result);

/// <summary>
/// Set a LISP variable value.
/// </summary>
/// <param name="name">The variable name.</param>
/// <param name="rb">The variable value</param>
public static void SetLispSym(string name, ResultBuffer rb)
{
acedPutSym(name, rb.UnmanagedObject);
}

[System.Security.SuppressUnmanagedCodeSecurity]
[DllImport("accore.dll", EntryPoint = "acedGetSym",
CharSet = CharSet.Unicode, CallingConvention = CallingConvention.Cdecl)]
extern static private int acedGetSym(string args, out IntPtr result);

/// <summary>
/// Get a LISP variable value.
/// </summary>
/// <param name="name">The variable name.</param>
/// <returns>The variable value or null if failed.</returns>
public static ResultBuffer GetLispSym(string name)
{
IntPtr ip = IntPtr.Zero;
int status = acedGetSym(name, out ip);
if (status == (int)PromptStatus.OK && ip != IntPtr.Zero)
{
return ResultBuffer.Create(ip, true);
}
return null;
}
//当然，要读取这个变量，首先要设置或者加载这个变量
ResultBuffer rb1114c = GetLispSym("dydj");
float intRetio=1;
     foreach (TypedValue val in (System.Collections.IEnumerable)rb1114c)
     {
          intRetio = (float)Convert.ToDouble((val.Value.ToString()));//根据你设置的类型进行转换
     }