插件开发百问百答中代码问题

[code]FormMetadata materialMetada =
MetaDataServiceHelper.Load(this.Context, "T_BD_MATERIAL") as FormMetadata;

QueryBuilderParemeter queryParameter = new QueryBuilderParemeter();
queryParameter.BusinessInfo = materialMetada.BusinessInfo;
queryParameter.FilterClauseWihtKey = "FMaterailId = 1.01.001.0055";

DynamicObject[] objs = BusinessDataServiceHelper.Load(
this.Context,
materialMetada.BusinessInfo.GetDynamicObjectType(),
queryParameter);[/code]这段代码执行的时候会有报错

这个元数据的ID如何获取呢？从哪里查某个单据或者基础资料的元数据ID？