如何使用 CrmServiceClient 设置空属性值

Question

我正在努力使用 CrmServiceClient 将属性值更新为 null。

我的代码对于非 null 值工作正常但失败并出现异常：

Object reference not set to an instance of an object. at Microsoft.Xrm.Tooling.Connector.CrmServiceClient.AddValueToPropertyList(KeyValuePair2 Field, AttributeCollection PropertyList) at Microsoft.Xrm.Tooling.Connector.CrmServiceClient.UpdateEntity(String entityName, String keyFieldName, Guid id, Dictionary2 fieldList, String applyToSolution, Boolean enabledDuplicateDetection, Guid batchId)

每当我尝试设置空值时。

到目前为止，我已经尝试了以下方法：

// create Crm service client object
CrmServiceClient svc = new CrmServiceClient(
new System.Net.NetworkCredential("username", "password", "domain"),
                "crmhost",
                "443",
                "crmorganization",
                false,
                true
                );

// check the connection to CRM was successful
if (!svc.IsReady)
{
    throw new Exception("Could not connect to CRM Organization.", svc.LastCrmException);
}

// create a Dictionary to store the attributes to be added to the entity
Dictionary<string, CrmDataTypeWrapper> attributes = new Dictionary<string, CrmDataTypeWrapper>();

//this doesn't work
attributes.Add("new_somedatefield", null);

// and this doesn't work
attributes.Add("new_somedatefield", new CrmDataTypeWrapper(null, CrmFieldType.CrmDateTime));

// this also doesn't work
DateTime? nullDate = new DateTime();
nullDate = null;
attributes.Add("new_somedatefield", new CrmDataTypeWrapper(nullDate, CrmFieldType.CrmDateTime));

svc.UpdateEntity("new_entityname", "new_entitynameid", (Guid)data[metaData.PrimaryIdAttribute], attributes));

文档中没有特别提到设置空值。

有没有人成功做到这一点？

编辑 - 为了阐明我需要以 Dynamics CRM 2015 为目标，CrmServiceClient 上的更新方法要到 2016 年才可用。

Answer 1

这应该有效。

Entity ent = new Entity("entityname");
ent.Attributes["datefieldname"] = null;
ent.id = Id;
service.Update(ent);