AutoCAD.Net/C#.Net QQ群:193522571 遍历块属性值时，如何避免遍历到已经删除的属性？

将这一句中加入openerased的选项，这样对于已经删除的块就不会去遍历了。

AttributeReference attRef = (AttributeReference)trans.GetObject(attId, OpenMode.ForRead,true);

/// <summary>
/// 获取指定名称的块属性值
/// </summary>
/// <param name="blockReferenceId">块参照的Id</param>
/// <param name="attributeName">属性名</param>
/// <returns>返回指定名称的块属性值</returns>
public static string GetAttributeInBlockReference(this ObjectId blockReferenceId, string attributeName)
{
string attributeValue = string.Empty; // 属性值
Database db = blockReferenceId.Database;
using (Transaction trans = db.TransactionManager.StartTransaction())
{
// 获取块参照
BlockReference bref = (BlockReference)trans.GetObject(blockReferenceId, OpenMode.ForRead);
// 遍历块参照的属性
foreach (ObjectId attId in bref.AttributeCollection)
{
// 获取块参照属性对象
AttributeReference attRef = (AttributeReference)trans.GetObject(attId, OpenMode.ForRead,true);
//判断属性名是否为指定的属性名
if (attRef.Tag.ToUpper() == attributeName.ToUpper())
{
attributeValue = attRef.TextString;//获取属性值
break;
}
}
trans.Commit();
}
return attributeValue; //返回块属性值
}