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DataServiceContext Class

The DataServiceContext represents the runtime context of the data service.

System.Object
  System.Data.Services.Client.DataServiceContext

Namespace:  System.Data.Services.Client
Assembly:  System.Data.Services.Client (in System.Data.Services.Client.dll)
public class DataServiceContext

The DataServiceContext type exposes the following members.

  Name Description
Public method DataServiceContext Initializes a new instance of the DataServiceContext class with the specified serviceRoot.
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  Name Description
Public property ApplyingChanges Gets a value that indicates whether the DataServiceContext is currently applying changes to tracked objects.
Public property BaseUri Gets the absolute URI identifying the root of the target data service.
Public property Credentials Gets or sets the authentication information that is used by each query created by using the DataServiceContext object.
Public property DataNamespace Gets or sets the XML namespace for data items, not metadata items, of an Atom payload.
Public property Entities Gets a list of all the resources currently being tracked by the DataServiceContext.
Public property IgnoreMissingProperties Gets or sets whether the properties read from the type must be mapped to properties on the client-side type.
Public property IgnoreResourceNotFoundException Gets or sets whether an exception is raised when a 404 error (resource not found) is returned by the data service.
Public property Links Gets the collection of all associations or links currently being tracked by the DataServiceContext object.
Public property MergeOption Gets or sets the synchronization option for receiving entities from a data service.
Public property ResolveName Gets or sets a function to override the default type resolution strategy used by the client library when you send entities to a data service.
Public property ResolveType Gets or sets a function that is used to override the default type resolution option that is used by the client library when receiving entities from a data service.
Public property SaveChangesDefaultOptions Gets or sets the SaveChangesOptions values that are used by the SaveChanges method.
Public property Timeout Gets or sets the time-out option (in seconds) that is used for the underlying HTTP request to the data service.
Public property TypeScheme Gets or sets the URI used to indicate what type scheme is used by the service.
Public property UsePostTunneling Gets or sets a Boolean value that indicates whether to use post tunneling.
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  Name Description
Public method AddLink Adds the specified link to the set of objects the DataServiceContext is tracking.
Public method AddObject Adds the specified object to the set of objects that the DataServiceContext is tracking.
Public method AddRelatedObject Adds a related object to the context and creates the link that defines the relationship between the two objects in a single request.
Public method AttachLink Notifies the DataServiceContext to start tracking the specified link that defines a relationship between entity objects.
Public method AttachTo(String, Object) Notifies the DataServiceContext to start tracking the specified resource and supplies the location of the resource within the specified resource set.
Public method AttachTo(String, Object, String) Notifies the DataServiceContext to start tracking the specified resource and supplies the location of the resource in the specified resource set.
Public method BeginExecute(Of T)(DataServiceQueryContinuation(Of T), AsyncCallback, Object) Asynchronously sends a request to the data service to retrieve the next page of data in a paged query result.
Public method BeginExecute(Of TElement)(Uri, AsyncCallback, Object) Asynchronously sends the request so that this call does not block processing while waiting for the results from the service.
Public method BeginExecuteBatch Asynchronously submits a group of queries as a batch to the data service.
Public method BeginGetReadStream Asynchronously gets binary property data for the specified entity as a data stream along with the specified message headers.
Public method BeginLoadProperty(Object, String, AsyncCallback, Object) Asynchronously loads the value of the specified property from the data service.
Public method BeginLoadProperty(Object, String, DataServiceQueryContinuation, AsyncCallback, Object) Asynchronously loads the next page of related entities from the data service by using the supplied query continuation object.
Public method BeginLoadProperty(Object, String, Uri, AsyncCallback, Object) Asynchronously loads a page of related entities from the data service by using the supplied next link URI.
Public method BeginSaveChanges(AsyncCallback, Object) Asynchronously submits the pending changes to the data service collected by the DataServiceContext since the last time changes were saved.
Public method BeginSaveChanges(SaveChangesOptions, AsyncCallback, Object) Asynchronously submits the pending changes to the data service collected by the DataServiceContext since the last time changes were saved.
Public method CancelRequest Attempts to cancel the operation that is associated with the supplied IAsyncResult object.
Public method CreateQuery(Of T) Creates a data service query for data of a specified generic type.
Public method DeleteLink Changes the state of the link to deleted in the list of links being tracked by the DataServiceContext.
Public method DeleteObject Changes the state of the specified object to be deleted in the DataServiceContext.
Public method Detach Removes the entity from the list of entities that the DataServiceContext is tracking.
Public method DetachLink Removes the specified link from the list of links being tracked by the DataServiceContext.
Public method EndExecute(Of TElement) Called to complete the BeginExecute.
Public method EndExecuteBatch Called to complete the BeginExecuteBatch.
Public method EndGetReadStream Called to complete the asynchronous operation of retrieving a binary property as a stream.
Public method EndLoadProperty Called to complete the BeginLoadProperty operation.
Public method EndSaveChanges Called to complete the BeginSaveChanges operation.
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Public method Execute(Of T)(DataServiceQueryContinuation(Of T)) Sends a request to the data service to retrieve the next page of data in a paged query result.
Public method Execute(Of TElement)(Uri) Sends a request to the data service to execute a specific URI.
Public method ExecuteBatch Submits a group of queries as a batch to the data service.
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method GetEntityDescriptor Gets the EntityDescriptor for the supplied entity object.
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetLinkDescriptor Gets the LinkDescriptor for a specific link that defines the relationship between two entities.
Public method GetMetadataUri Gets a URI of the location of .edmx metadata.
Public method GetReadStream(Object) Gets binary property data for the specified entity as a data stream.
Public method GetReadStream(Object, DataServiceRequestArgs) Gets binary property data for the specified entity as a data stream along with the specified message headers.
Public method GetReadStream(Object, String) Gets binary property data for the specified entity as a data stream, with the specified Accept message header.
Public method GetReadStreamUri Gets the URI that is used to return binary property data as a data stream.
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Public method LoadProperty(Object, String) Loads deferred content for a specified property from the data service.
Public method LoadProperty(Object, String, DataServiceQueryContinuation) Loads the next page of related entities from the data service by using the supplied query continuation object.
Public method LoadProperty(Object, String, Uri) Loads a page of related entities by using the supplied next link URI.
Public method LoadProperty(Of T)(Object, String, DataServiceQueryContinuation(Of T)) Loads the next page of related entities from the data service by using the supplied generic query continuation object.
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method SaveChanges Saves the changes that the DataServiceContext is tracking to storage.
Public method SaveChanges(SaveChangesOptions) Saves the changes that the DataServiceContext is tracking to storage.
Public method SetLink Notifies the DataServiceContext that a new link exists between the objects specified and that the link is represented by the property specified by the sourceProperty parameter.
Public method SetSaveStream(Object, Stream, Boolean, DataServiceRequestArgs) Sets a new data stream as the binary property of an entity, with the specified settings in the request message.
Public method SetSaveStream(Object, Stream, Boolean, String, String) Sets a new data stream as the binary property of an entity. The specified Content-Type and Slug headers are included in the request message.
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
Public method TryGetEntity(Of TEntity) Test retrieval of an entity being tracked by the DataServiceContext by reference to the URI of the entity.
Public method TryGetUri Retrieves the canonical URI associated with the specified entity, if available.
Public method UpdateObject Changes the state of the specified object in the DataServiceContext to Modified.
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  Name Description
Public event ReadingEntity Occurs after entity data has been completely read into the entity object.
Public event SendingRequest Occurs when a new HttpWebRequest has been created.
Public event WritingEntity Occurs after an entity has been fully serialized into XML in a request message.
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WCF Data Services are stateless, but the DataServiceContext is not. State on the client is maintained between interactions in order to support features such as update management. This class, and the DataServiceQuery class that represents a particular HTTP request to a data service, are the two main classes in the client library.

The following example shows how to use the DataServiceContext generated by the Add Service Reference tool to implicitly execute a query against the Northwind data service that returns all customers. The URI of the requested Customers entity set is determined automatically by the context. The query is executed implicitly when the enumeration occurs. The Northwind data service is created when you complete the WCF Data Services quickstart.


// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);

// Define a new query for Customers.
DataServiceQuery<Customer> query = context.Customers;

try
{
    // Enumerate over the query result, which is executed implicitly.
    foreach (Customer customer in query)
    {
        Console.WriteLine("Customer Name: {0}", customer.CompanyName);
    }
}
catch (DataServiceQueryException ex)
{
    throw new ApplicationException(
        "An error occurred during query execution.", ex);
}


.NET Framework

Supported in: 4, 3.5 SP1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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