1.??的使用,就是判断值是否为null,为null的话，给赋初值，否则就直接取值。
decimal new_amount = 0;
if (targetEntity.Contains("字段1"))
{
//?? 判断(targetEntity["字段1"] as Money为null的话，赋值为0
new_amount = (targetEntity["字段1"] as Money ?? new Money(0M)).Value;
}
注:字段1为货币（Money）类型。
2. 一般从Targt 中取值,必须先判断是否存在，然后在判断不为null.不然会报错，因为字段1有可能不在Target里面，意思
targetEntity.Contains("字段1")为False,那么直接写targetEntity["字段1"] != null，就会报错。不信，大家可以试试。
decimal new_amount = 0;
if (targetEntity.Contains("字段1") && targetEntity["字段1"] != null)
{
new_amount = (targetEntity["字段1"] as Money).Value;
}
而不能
if (targetEntity["字段1"] != null && targetEntity.Contains("字段1"))
{
new_amount = (targetEntity["字段1"] as Money).Value;
}
注:字段1为货币（Money）类型。
3.可以将Entity取出的字段放在AttributeCollection 属性集合中去，然后可以直接从这个属性集合中取值。
/// <summary>
/// 获取属性集合
/// </summary>
/// <param name="dataEntity">Entity</param>
/// <returns>返回属性集合</returns>
public AttributeCollection GetTriggerData(Entity dataEntity)
{
AttributeCollection parames = new AttributeCollection(); if (dataEntity != null)
{
//先将字段放在一个字符串数组中
string[] arrayStr = { "new_actiontype",
"new_po_status", "new_sort",
"new_detailitem","new_costfrom","new_bgcontrolperiod" };
//foreache 循环判断，把dataEntity的索引赋给parames中去。
foreach (var item in arrayStr)
{
if (dataEntity.Contains(item) && dataEntity[item] != null)
{
parames[item] = dataEntity[item];
}
}
}
return parames;
}
调用：AttributeCollection parmes = GetTriggerData(dataEntity);
4.根据很多条件，查询一个实体的实体集合，除了fetchxml,也可以用QueryByAttribute。
/// <summary>
/// 根据所属预算品类、费用项目、费用归属和预算控制期间获取预算费用项实体
/// </summary>
/// <param name="service">crm组织服务</param>
/// <param name="parmes">属性集合</param>
/// <returns>返回Entity</returns>
public Entity GetBugetByParmes(IOrganizationService service, AttributeCollection parmes)
{
QueryByAttribute query = new QueryByAttribute("new_buget");查询的实体
query.ColumnSet = new ColumnSet("new_bugetid");//查询的列
query.AddAttributeValue("statecode", 0);//查询的条件
query.AddAttributeValue("new_sort", (parmes["new_sort"] as EntityReference).Id);
query.AddAttributeValue("new_expenseitem", (parmes["new_detailitem"] as EntityReference).Id);
query.AddAttributeValue("new_bugetunit", (parmes["new_costfrom"] as EntityReference).Id);
query.AddAttributeValue("new_bedgetsheet", (parmes["new_bgcontrolperiod"] as EntityReference).Id); EntityCollection acc_new_buget = service.RetrieveMultiple(query); Entity new_bugetEntity = null; if (acc_new_buget.Entities.Count > )
{
new_bugetEntity = acc_new_buget.Entities[] as Entity;
} return new_bugetEntity;
}
5.Double? 类型+？ ?是表示值类型可以为null,值类型的初始化不为null，比如int的初始值为0.
具体可以参考msdn:http://msdn.microsoft.com/zh-cn/library/1t3y8s4s(v=vs.90).aspx
//查询
QueryByAttribute query = new QueryByAttribute("new_exp_undertaker");
query.ColumnSet = new ColumnSet("new_ratio_undertaker");
query.AddAttributeValue("new_pe_undertaker", new_promotion_peid); EntityCollection accEntityColls = service.RetrieveMultiple(query); if (accEntityColls.Entities.Count == ) return; foreach (Entity accEntity in accEntityColls.Entities)
{
Double? new_ratio_undertaker = accEntity.Contains("new_ratio_undertaker")
? accEntity["new_ratio_undertaker"] as Double? : new Double?();
//更新
UpdateNew_deficit(service, new_ratio_undertaker, new_writeoff, accEntity.Id);
}
取值：(decimal)((new_ratio_undertaker.Value)
6. 如果一个实体上其他字段汇总到另外字段上，比如字段a,b,c,d 需要d = a+b*c，当进行这样子操作的时候，只有Create和Update，而且都为Pre_validation操作，能放到
Pre_validation(10)处理，尽量放到Pre_validation处理，因为这样子性能比较好，至于具体原因可以看SDK。
还有一般做check,或者导入数据根据一个lookup字段的带出值，赋给另外一个字段，也可以放在这里处理。CRM4的话是context.Stage == 10，Pre前期处理。这里暂不说明。
Entity targetEntity = context.InputParameters["Target"] as Entity; //消息名称
string messageName = context.MessageName; decimal sumNew_budgetbalance = ; switch (messageName)
{
case "Create":
sumNew_budgetbalance = DoCreateSumNew_budgetbalance(targetEntity);
break;
case "Update":
sumNew_budgetbalance = DoUpdateSumNew_budgetbalance(targetEntity, preImageEntity);
break;
} targetEntity["new_budgetbalance"] = new Money(sumNew_budgetbalance); context.InputParameters["Target"] = targetEntity;//把提交的值放到Target中，当保存之后，就会把这些值保存到数据库中。 } .RegisterFile.crmregister: <Plugin Description="Plug-in to New_bugetUpdatenew_CalcuBudgetbalance" FriendlyName="New_bugetUpdatenew_CalcuBudgetbalance" Name="Frensworkz.LibyCrm.Plugins.New_bugetUpdatenew_CalcuBudgetbalance" Id="b5985a39-e284-e311-ad3b-00155d386b48" TypeName="Frensworkz.LibyCrm.Plugins.New_bugetUpdatenew_CalcuBudgetbalance">
<Steps>
<clear />
<Step CustomConfiguration="" Name="New_bugetUpdatenew_CalcuBudgetbalance" Description="New_bugetUpdatenew_CalcuBudgetbalance Create" Id="b6985a39-e284-e311-ad3b-00155d386b48" MessageName="Create" Mode="Synchronous" PrimaryEntityName="new_buget" Rank="" SecureConfiguration="" Stage="PreOutsideTransaction" SupportedDeployment="ServerOnly">
<Images />
</Step>
<Step CustomConfiguration="" Name="New_bugetUpdatenew_CalcuBudgetbalance" Description="New_bugetUpdatenew_CalcuBudgetbalance Update" Id="b9985a39-e284-e311-ad3b-00155d386b48" MessageName="Update" Mode="Synchronous" PrimaryEntityName="new_buget" Rank="" SecureConfiguration="" Stage="PreOutsideTransaction" SupportedDeployment="ServerOnly">
<Images>
<Image Attributes="new_quotabudget,new_ratio,new_saletarget,new_standardbuget,new_programholdbudget,new_noprogramhold,new_sales_app,new_pe_ch_money,new_po_ch_money,new_sales_release,new_adjust_fee,new_send_in,new_adjust_reduce" EntityAlias="PreImage" Id="bc985a39-e284-e311-ad3b-00155d386b48" MessagePropertyName="Target" ImageType="PreImage" />
</Images>
</Step>
</Steps>
</Plugin>
1
大家肯定会问，为什么会这样子写Plugin，这里暂不说明。
7.将明细中的金额汇总到主表上的一个字段时，很多人都没有考虑到SetStateDynamicEntity这个步骤。
base.RegisteredEvents.Add(new Tuple<int, string, string, Action<LocalPluginContext>>(, "Create", "new_po", new Action<LocalPluginContext>(ExecuteNew_po_New_po_status_SumNew_tt_budget)));
base.RegisteredEvents.Add(new Tuple<int, string, string, Action<LocalPluginContext>>(, "Update", "new_po", new Action<LocalPluginContext>(ExecuteNew_po_New_po_status_SumNew_tt_budget)));
base.RegisteredEvents.Add(new Tuple<int, string, string, Action<LocalPluginContext>>(, "Delete", "new_po", new Action<LocalPluginContext>(ExecuteNew_po_New_po_status_SumNew_tt_budget)));
base.RegisteredEvents.Add(new Tuple<int, string, string, Action<LocalPluginContext>>(, "SetStateDynamicEntity", "new_po", new Action<LocalPluginContext>(ExecuteNew_po_New_po_status_SumNew_tt_budget))); protected void ExecuteNew_po_New_po_status_SumNew_tt_budget(LocalPluginContext localContext)
{
if (localContext == null)
{
throw new ArgumentNullException("localContext");
} IPluginExecutionContext context = localContext.PluginExecutionContext; IOrganizationService service = localContext.OrganizationServiceAll; Entity dataEntity = null;
switch (context.MessageName)
{
case "Create":
dataEntity = context.InputParameters["Target"] as Entity;
break;
case "Update":
case "SetStateDynamicEntity":
dataEntity = context.PostEntityImages[this.postImageAlias] as Entity;
break;
case "Delete":
dataEntity = context.PreEntityImages[this.preImageAlias] as Entity;
break;
} New_po_New_po_status_SumNew_tt_budgetAction(service, dataEntity); }
8.从DataRow中取值的时候，需要判断row["new_sort"].ToString()不能为空。
foreach (DataRow row in ds.Tables[].Rows)
{
if (!string.IsNullOrEmpty(row["new_sort"].ToString()))
{
new_sort = new Guid(row["new_sort"].ToString());
}
}
9.新建(Create)的时候，需要判断preImageEntity != null。
private readonly string preImageAlias = "image";
Entity preImageEntity = (context.PreEntityImages != null && context.PreEntityImages.Contains(this.preImageAlias)) ? context.PreEntityImages[this.preImageAlias] : null; if(messageName =="Create")
{
if(preImageEntity != null)
{
if(preImageEntity.Contains("new_promotion_pe"))
{
new_promotion_peId = (preImageEntity["new_promotion_pe"] as EntityReference).Id;
}
}
}