Microsoft Dynamics CRM 2016年

Question

我试图编写一个提取xml来从设施/设备实体中检索BusinessUnitID和设备ID，我已经用c＃代码编写了此提取xml，但是它在行（粗体行）中引发了空引用异常/System.NullReferenceException。我在设施/设备实体中没有空值。 这是我的代码：

  private static OrganizationService _orgService;
  string fetchBU = @"<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>
    <entity name='equipment'>
        <attribute name='name' />
        <attribute name='equipmentid' />
        <order attribute='name' descending='false' />
      <filter type='and'>
         <condition attribute='businessunitid' operator='eq-businessid' />
      </filter>
    </entity>
   </fetch>";

EntityCollection ec = _orgService.RetrieveMultiple(new FetchExpression(fetchBU));
if (ec.Entities.Count > 0)
{
   Guid BusinessUnitId = (Guid)ec[0].Attributes["businessunitid"];
}

有人可以建议我吗？ 提前致谢！

Answer 1

您不仅需要在以下条件中，还需要在属性内添加businessunitid ：

string fetchBU = @"<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>
    <entity name='equipment'>
        <attribute name='name' />
        <attribute name='equipmentid' />
        <attribute name='businessunitid' />
        <order attribute='name' descending='false' />
      <filter type='and'>
         <condition attribute='businessunitid' operator='eq-businessid' />
      </filter>
    </entity>
   </fetch>";