DataAsyncCommand.DeriveSchemaAsync Method

Artikel
02/28/2011

Derives, in an asynchronous manner, the schema of the specified command.

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

Syntax

'Declaration
Public Sub DeriveSchemaAsync ( _
    command As String, _
    commandType As DataCommandType, _
    parameters As IVsDataParameter(), _
    commandTimeout As Integer, _
    userState As Object _
)

public void DeriveSchemaAsync(
    string command,
    DataCommandType commandType,
    IVsDataParameter[] parameters,
    int commandTimeout,
    Object userState
)

public:
virtual void DeriveSchemaAsync(
    String^ command, 
    DataCommandType commandType, 
    array<IVsDataParameter^>^ parameters, 
    int commandTimeout, 
    Object^ userState
) sealed

abstract DeriveSchemaAsync : 
        command:string * 
        commandType:DataCommandType * 
        parameters:IVsDataParameter[] * 
        commandTimeout:int * 
        userState:Object -> unit 
override DeriveSchemaAsync : 
        command:string * 
        commandType:DataCommandType * 
        parameters:IVsDataParameter[] * 
        commandTimeout:int * 
        userState:Object -> unit

public final function DeriveSchemaAsync(
    command : String, 
    commandType : DataCommandType, 
    parameters : IVsDataParameter[], 
    commandTimeout : int, 
    userState : Object
)

Parameters

command
Type: System.String
The command for which the schema is derived.

commandType
Type: Microsoft.VisualStudio.Data.Services.SupportEntities.DataCommandType
A value from the DataCommandType enumeration representing the command type for the indicated command. The value specifies how to interpret the contents of the command parameter.

parameters
Type: array<Microsoft.VisualStudio.Data.Services.SupportEntities.IVsDataParameter[]
A list of parameters to pass with the command.

commandTimeout
Type: System.Int32
Amount of time, in seconds, before which the command times out.

userState
Type: System.Object
The object on which this method calls back as the command progresses.

Implements

IVsDataAsyncCommand.DeriveSchemaAsync(String, DataCommandType, array<IVsDataParameter[], Int32, Object)

Exceptions

Exception	Condition
ArgumentNullException	The command or userState parameter is nulla null reference (Nothing in Visual Basic).
ArgumentOutOfRangeException	The commandTimeout parameter is less than -1.

Remarks

This method performs the same operation as the DeriveSchema method, but in an asynchronous manner.

If the value of the commandTimeout parameter is 0, there is no timeout (or, timeout is infinite); if the value is -1, the timeout period is that set by the data provider.

The userState parameter uniquely identifies the specific asynchronous operation and is passed back as part of the event arguments for the DeriveSchemaCompleted event so that a listener can determine which asynchronous process completed.

Hinweis

Other exceptions that occur indicate that the parameter derivation failed for a provider-specified reason.

.NET Framework Security

Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

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