Microsoft Dynamics 2016

Question

我试图编写一个fetch来从设施/设备实体中检索BusinessUnitID和设备ID，我已经用c#代码编写了这个获取xml，但是它在行(粗体行)中抛出了一个空引用异常/System.NullReferenceException--我在设施/设备实体中没有任何空值。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"];
}

​

​

有人能给我建议一下吗？提前感谢！

Answer 1

您还需要在属性中添加businessunitid，而不仅仅是在以下条件下：

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>";