应用到: CRM 2015 on-prem, CRM Online
Defines a complex query to retrieve attribute metadata for entities retrieved using an EntityQueryExpression
命名空间: Microsoft.Xrm.Sdk.Metadata.Query
程序集: Microsoft.Xrm.Sdk (在 Microsoft.Xrm.Sdk.dll 中)
语法
声明
<DataContractAttribute(Name:="AttributeQueryExpression", Namespace:="https://schemas.microsoft.com/xrm/2011/Metadata/Query")> _
Public NotInheritable Class AttributeQueryExpression
Inherits MetadataQueryExpression
[DataContractAttribute(Name="AttributeQueryExpression", Namespace="https://schemas.microsoft.com/xrm/2011/Metadata/Query")]
public sealed class AttributeQueryExpression : MetadataQueryExpression
备注
The following example shows the use of an AttributeQueryExpression to retrieve entity metadata.
//A condition expresson to return optionset attributes
MetadataConditionExpression[] optionsetAttributeTypes = new MetadataConditionExpression[] {
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.Picklist),
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.State),
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.Status),
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.Boolean)
};
//A filter expression to apply the optionsetAttributeTypes condition expression
MetadataFilterExpression AttributeFilter = new MetadataFilterExpression(LogicalOperator.Or);
AttributeFilter.Conditions.AddRange(optionsetAttributeTypes);
//A Properties expression to limit the properties to be included with attributes
MetadataPropertiesExpression AttributeProperties = new MetadataPropertiesExpression() { AllProperties = false };
AttributeProperties.PropertyNames.Add("OptionSet");
AttributeProperties.PropertyNames.Add("AttributeType");
...
//An entity query expression to combine the filter expressions and property expressions for the query.
EntityQueryExpression entityQueryExpression = new EntityQueryExpression()
{
Criteria = EntityFilter,
Properties = EntityProperties,
AttributeQuery = new AttributeQueryExpression()
{
Criteria = AttributeFilter,
Properties = AttributeProperties
},
LabelQuery = labelQuery
};
//Retrieve the metadata for the query without a ClientVersionStamp
RetrieveMetadataChangesResponse initialRequest = getMetadataChanges(entityQueryExpression, null, DeletedMetadataFilters.OptionSet);
继承层次结构
System.Object
Microsoft.Xrm.Sdk.Metadata.Query.MetadataQueryBase
Microsoft.Xrm.Sdk.Metadata.Query.MetadataQueryExpression
Microsoft.Xrm.Sdk.Metadata.Query.AttributeQueryExpression
线程安全性
此类型的所有公共静态（Visual Basic 中的 Shared）成员都是线程安全成员。不保证任何实例成员是线程安全成员。
平台
开发平台
Windows Vista、Windows Server 2003 和
目标平台
Windows 98,Windows 2000,Windows 2000 Server,Windows CE,Windows Server 2008,Windows 98 Second Edition,Pocket PC,智能电话,Windows Server 2003,Windows XP Professional,Windows Vista,Windows XP
Change History
另请参阅
参考
AttributeQueryExpression 成员
Microsoft.Xrm.Sdk.Metadata.Query 命名空间
其他资源
Query and Capture Changes to Metadata
Sample: Query Metadata and Detect Changes
Send comments about this topic to Microsoft.
© 2014 Microsoft Corporation. All rights reserved.