DataAsyncCommand Class
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
'Declaración
<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 | |
|---|---|---|
.gif "Protected method") |
DataAsyncCommand | Class constructor. Instantiates a nonparameterized instance of the DataAsyncCommand class. |
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Methods
| Name | Description | |
|---|---|---|
.gif "Public method") |
AsyncDeriveParameters | Derives, in an asynchronous manner, a set of parameters for use with a specified command. |
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AsyncDeriveSchema | Derives, in an asynchronous manner, the schema of the specified command. |
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AsyncExecute | Executes a command in an asynchronous manner. |
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AsyncExecuteWithoutResults | Executes, in an asynchronous manner, a command that does not return any results beyond an integer value indicating status. |
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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. |
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Cancel() | Cancels the asynchronous call, returning immediately. |
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Cancel(Boolean) | Cancels the asynchronous call, returning either immediately (asynchronously) or after waiting for the call to be fully cancelled (synchronously). |
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Equals | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
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Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
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GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
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GetType | Gets the Type of the current instance. (Inherited from Object.) |
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MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
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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.