AutoCAD Civil3D 2022 ActiveX匹配对象名称报错求助

已在Civil 3D中定义相关库，尝试将选中的CAD文本对象内容与无站点对齐对象名称匹配时，触发错误提示No method or operation has been applied，问题出在遍历AeccAlignmentsSiteless集合的代码部分，C#和VB.NET实现均存在该问题。

原问题代码 #

AcadApplication ACAD = (AcadApplication)System.Runtime.InteropServices.Marshal.GetActiveObject("AutoCAD.Application.24");
AcadDocument ADOC = ACAD.ActiveDocument;
AeccApplication CivilApp = ACAD.GetInterfaceObject("AeccXUiLand.AeccApplication.13.4");
AeccDocument AeccDoc = (AeccDocument)CivilApp.ActiveDocument;
            
AeccAlignmentsSiteless aliS = AeccDoc.AlignmentsSiteless;
           
AeccAlignment TAlignment;

object o1;
object o2;

AcadText AliName = null;
         
ADOC.Utility.GetEntity(out o1, out o2, "Select an alignment name on CAD");
AliName = (AcadText)o1;

// HERE THE PROBLEM!
foreach (AeccAlignment item in aliS)
{
    if (AliName.TextString == item.Name.ToString())
    {
        TAlignment = item;
                  
        break;
    }
}

问题原因与修复方案 #

AeccAlignmentsSiteless是COM对象集合，不支持C#原生foreach遍历（未实现兼容的IEnumerable接口），必须通过COM集合标准的Item属性结合索引访问，且COM集合索引通常从1开始而非0。

修改后的代码 #

AcadApplication ACAD = (AcadApplication)System.Runtime.InteropServices.Marshal.GetActiveObject("AutoCAD.Application.24");
AcadDocument ADOC = ACAD.ActiveDocument;
AeccApplication CivilApp = ACAD.GetInterfaceObject("AeccXUiLand.AeccApplication.13.4");
AeccDocument AeccDoc = (AeccDocument)CivilApp.ActiveDocument;
            
AeccAlignmentsSiteless aliS = AeccDoc.AlignmentsSiteless;
AeccAlignment TAlignment = null;

object o1;
object o2;

ADOC.Utility.GetEntity(out o1, out o2, "Select an alignment name on CAD");
// 增加类型校验，避免非文本对象导致的转换错误
if (!(o1 is AcadText))
{
    ADOC.Utility.Prompt("请选择CAD文本对象！");
    return;
}
AcadText AliName = (AcadText)o1;

// 改用COM集合兼容的遍历方式
int alignmentCount = aliS.Count;
for (int i = 0; i < alignmentCount; i++)
{
    // COM集合索引从1开始
    AeccAlignment item = aliS.Item(i + 1) as AeccAlignment;
    if (item != null && AliName.TextString.Equals(item.Name, StringComparison.OrdinalIgnoreCase))
    {
        TAlignment = item;
        break;
    }
}

额外优化说明 #

• 增加了选中对象的类型校验，避免非文本对象导致的类型转换异常
• 使用StringComparison.OrdinalIgnoreCase增强匹配鲁棒性（若需严格大小写匹配可移除该参数）
• 增加空值判断，防止Item返回null时引发空引用异常

内容的提问来源于stack exchange，提问作者H3LLF1R3