TypeDescriptor, classe (Microsoft.Office.Server.ApplicationRegistry.Administration)
Defines the data type of a parameter for a method.
Espace de noms : Microsoft.Office.Server.ApplicationRegistry.Administration
Assembly : Microsoft.SharePoint.Portal (dans microsoft.sharepoint.portal.dll)
Syntaxe
'Déclaration
<SharePointPermissionAttribute(SecurityAction.InheritanceDemand, ObjectModel:=True)> _
<SharePointPermissionAttribute(SecurityAction.Demand, ObjectModel:=True)> _
Public Class TypeDescriptor
Inherits AccessControlledMetadataObject
'Utilisation
Dim instance As TypeDescriptor
[SharePointPermissionAttribute(SecurityAction.InheritanceDemand, ObjectModel=true)]
[SharePointPermissionAttribute(SecurityAction.Demand, ObjectModel=true)]
public class TypeDescriptor : AccessControlledMetadataObject
Remarques
Every Parameter object has a TypeDescriptor object that defines the data type of the parameter. It is the most complex metadata object. It is a hierarchical object that recursively describes an abstract data structure built of primitives. In addition, each leaf node of the TypeDescriptor tree points to a set of possible default values specified by the MethodInstance object Therefore, given a MethodInstance and a parameter, the parameter's TypeDescriptor is a recipe to instantiate a default value for that parameter.
In addition, TypeDescriptors form the heart of the Business Data Catalog's ability to transform complex backend APIs into simple stereotypical operations like Find, FindSpecific, CheckAccess, ad so on. Once you define detailed type information via the TypeDescriptor metadata, you can tag TypeDescriptors as slots where Identifiers or Filter values can be plugged in by the Business Data Catalog. For example, a TypeDescriptor in a Parameter that is tagged to receive the Identifier for an Entity, results in a Method that can be used as a SpecificFinder.
Use the IsCollection property on a return TypeDescriptor object to indicate wherever there are collections within the return parameter. Consider a Web method that return collections of customers, each customer of which contains a collection of Addresses. In this example, the flag must be set twice—once at the root Customer[] level, and then again at the Customer[0].Address[] level. However, a collection TypeDescriptor object can have only a single child TypeDescriptor object under it that represents the structure in the collection.
Business Data Catalog clients such as the Business Data Web Parts do not handle complex structures. For example, consider the following structures:
class Customer { String Name; Address address; }
class Address { Street street; String city; String zip; }
class Street { int Block; String street; }
To work around this limitation, Business Data Catalog supports the concept of "complex formatting." Because clients support flat structures of primitives, the Business Data Catalog will "render" complex structures as formatted strings via two mechanisms: a simple .NET Framework String formatter, or a more complex Renderer that one can write using any .NET language. This is accomplished by setting two String properties with the names "FormatString" (e.g. "{0}, {1} \n {2}, {3}") or "RendererDefinition" (MyMethodName!MyTypeName, MyAssemblyName), respectively. The Method object in the RendererDefinition must correspond to a public static .NET method on a public .NET Type that takes a single argument, which is an array of Objects. In either case, what gets passed to the Format string or to the .NET Renderer is basically an array of all the primitive child values of the complex structure, as modeled by the Business Data Catalog TypeDescriptor definition for that structure.
Avertissement
Complex formatting is slow; use it only if absolutely necessary.
A controlling property called "ComplexFormatting" must appear on any structure that contains complex fields, to enable complex rendering.
Notes
Be careful when tagging identifiers for complex formatting, because identifiers are used for both input and output to the back-end application (when getting the Addresses for a Customer, the Business Data Catalog looks for the Customer Key to give to the GetAddressesForCustomer method). If an identifier has been rendered as a formatted string, all type information is lost and it can no longer be used as input.
Exemple
The following code example shows you how to create a method, complete with method instances, filter descriptors, default values, and type descriptors, for the ProductModel entity in the AdventureWorks database.
Prerequisites
Make sure a Shared Service Provider has already been created.
Create an LOBSystem instance and set connection parameters as shown in Procédure : créer un objet LobSystem à l'aide du modèle objet Administration.
Create the ProductModel entity as shown in Procédure : créer une entité à l'aide du modèle objet Administration
Replace the constant value EnterYourSSPNameHere in the code with the name of your Shared Resource Provider.
Project References
Add the following Project References in your console application code project before running this sample:
Microsoft.SharePoint
Microsoft.SharePoint.Portal
Microsoft.Office.Server
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Office.Server.ApplicationRegistry.Administration;
using Microsoft.Office.Server.ApplicationRegistry.Infrastructure;
using WSSAdmin = Microsoft.SharePoint.Administration;
using OSSAdmin = Microsoft.Office.Server.Administration;
namespace Microsoft.SDK.SharePointServer.Samples
{
class GetStartedAndCreateSystem
{
const string yourSSPName ="EnterYourSSPNameHere";
static void Main(string[] args)
{
SetupBDC();
CreateFinderMethod();
Console.WriteLine("Press any key to exit...");
Console.Read();
}
static void SetupBDC()
{
SqlSessionProvider.Instance().SetSharedResourceProviderToUse(yourSSPName);
}
static void CreateFinderMethod()
{
LobSystemInstance mySysInstance = null;
LobSystemInstanceCollection sysInsCollection = ApplicationRegistry.Instance.GetLobSystemInstancesLikeName("AdventureWorksSampleFromCode");
foreach (LobSystemInstance sysInstance in sysInsCollection)
{
if (sysInstance.Name == "AdventureWorksSampleFromCode")
{
mySysInstance = sysInstance;
break;
}
}
EntityCollection entityColl = mySysInstance.LobSystem.Entities;
foreach (Entity entity in entityColl)
{
if (entity.Name == "ProductModel")
{
Method meth = entity.Methods.Create("GetProductModels", true, true);
meth.Properties.Add("RdbCommandText", "SELECT ProductModelID, Name, CatalogDescription FROM ProductModel WHERE Name LIKE @Name");
meth.Properties.Add("RdbCommandType", System.Data.CommandType.Text);
FilterDescriptor fd = meth.FilterDescriptors.Create("Name", true, "Microsoft.Office.Server.ApplicationRegistry.Runtime.WildcardFilter");
Parameter p1 = meth.Parameters.Create("@Name", true, Microsoft.Office.Server.ApplicationRegistry.MetadataModel.DirectionType.In, "Microsoft.Office.Server.ApplicationRegistry.Infrastructure.DotNetTypeReflector");
TypeDescriptor td1 = p1.CreateRootTypeDescriptor("Name", true, "System.String", null, fd, false);
Parameter p2 = meth.Parameters.Create("ProductModels", true, Microsoft.Office.Server.ApplicationRegistry.MetadataModel.DirectionType.Return, "Microsoft.Office.Server.ApplicationRegistry.Infrastructure.DotNetTypeReflector");
IList<Identifier> ids = new List<Identifier>(entity.Identifiers);
Identifier id = ids[0];
TypeDescriptor td2 = p2.CreateRootTypeDescriptor("ProductModelDataReader", true, "System.Data.IDataReader, System.Data, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089", null, null, true);
TypeDescriptor td21 = td2.ChildTypeDescriptors.Create("ProductModelDataRecord", true, "System.Data.IDataRecord, System.Data, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b77a5c561934e089", null, null, false);
TypeDescriptor td210 = td21.ChildTypeDescriptors.Create("ProductModelID", true, "System.Int32", id, null, false);
TypeDescriptor td211 = td21.ChildTypeDescriptors.Create("Name", true, "System.String", null, null, false);
TypeDescriptor td212 = td21.ChildTypeDescriptors.Create("CatalogDescription", true, "System.String", null, null, false);
MethodInstance methInst1 = meth.MethodInstances.Create("ProductModelFinder", true, td2, Microsoft.Office.Server.ApplicationRegistry.MetadataModel.MethodInstanceType.Finder);
MethodInstance methInst2 = meth.MethodInstances.Create("ProductModelSpecificFinder", true, td2, Microsoft.Office.Server.ApplicationRegistry.MetadataModel.MethodInstanceType.SpecificFinder);
IList<MethodInstance> methInstCollection = new List<MethodInstance>(entity.MethodInstances);
td1.SetDefaultValue(methInstCollection[0].Id, "%");
td1.SetDefaultValue(methInstCollection[1].Id, "%");
Console.WriteLine("Created the finder method successfully.");
break;
}
}
}
}
}
Hiérarchie d'héritage
System.Object
Microsoft.Office.Server.ApplicationRegistry.Administration.MetadataObject
Microsoft.Office.Server.ApplicationRegistry.Administration.AccessControlledMetadataObject
Microsoft.Office.Server.ApplicationRegistry.Administration.TypeDescriptor
Sécurité des threads
Les membres statiques publics de ce type (Shared en Visual Basic) sont sécurisés au niveau des threads. Il n'est pas garanti que les membres d'instance soient sécurisés au niveau des threads.
Voir aussi
Référence
Membres TypeDescriptor
Microsoft.Office.Server.ApplicationRegistry.Administration, espace de noms