# 如何从STEP文件中获取某个EntityInstance的ID？
1. [FAQ](/cn/faq)
2. »
3.
您可以先获取实体实例的OdDAIObjectId，然后从中提取编号（#）：
```
OdDAI::ApplicationInstance pInst = ...; // arbitrary instance of SDAI Model
```
```
OdDAIObjectId id = pInst->id();
```
```
OdDbHandle h = id.getHandle();
```
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```