DataAsyncCommand Class

Article
10/02/2013

Enables executing data commands in an asynchronous manner.

Inheritance Hierarchy

System.Object
Microsoft.VisualStudio.Data.DataAsyncCommand

Namespace: Microsoft.VisualStudio.Data
Assembly: Microsoft.VisualStudio.Data (in Microsoft.VisualStudio.Data.dll)

Syntax

'Declaration
<GuidAttribute("AD18952D-2ED0-48f3-B5E6-48992526EB93")> _
Public MustInherit Class DataAsyncCommand

[GuidAttribute("AD18952D-2ED0-48f3-B5E6-48992526EB93")]
public abstract class DataAsyncCommand

[GuidAttribute(L"AD18952D-2ED0-48f3-B5E6-48992526EB93")]
public ref class DataAsyncCommand abstract

[<AbstractClass>]
[<GuidAttribute("AD18952D-2ED0-48f3-B5E6-48992526EB93")>]
type DataAsyncCommand =  class end

public abstract class DataAsyncCommand

The DataAsyncCommand type exposes the following members.

Constructors

	Name	Description
	DataAsyncCommand	Class constructor. Instantiates a nonparameterized instance of the DataAsyncCommand class.

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Methods

	Name	Description
	AsyncDeriveParameters	Derives, in an asynchronous manner, a set of parameters for use with a specified command.
	AsyncDeriveSchema	Derives, in an asynchronous manner, the schema of the specified command.
	AsyncExecute	Executes a command in an asynchronous manner.
	AsyncExecuteWithoutResults	Executes, in an asynchronous manner, a command that does not return any results beyond an integer value indicating status.
	AsyncPrepare	Prepares, in an asynchronous manner, the specified command to be executed against the data source; the command may then be executed multiple times, with varying parameters.
	Cancel()	Cancels the asynchronous call, returning immediately.
	Cancel(Boolean)	Cancels the asynchronous call, returning either immediately (asynchronously) or after waiting for the call to be fully cancelled (synchronously).
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Remarks

DDEX providers can expose the ability to execute commands against their data source. This may include, but is not limited to, SQL statements, procedures, and functions.

Providers normally expose this functionality by implementing the DataCommand class, which provides synchronous command execution. When asynchronous command handling is needed, on the other hand, you can use the DataAsyncCommand class.

The DataAsyncCommand class extends command handling by providing asynchronous-capable versions of methods on the DataCommand class, as well as with methods for canceling an asynchronous function call.

The DDEX runtime provides a default implementation of this class, which delegates to the synchronous methods provided by the DataCommand class. A DDEX provider should only need to provide their own implementation of this class in special situations.

An implementation of this class is exposed as a service on the data connection.

Thread Safety

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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