IVsDataProviderDynamicSupport.GetUnsupportedReason Method

Gets a localized string describing the reason an operation is not supported, for the specified DDEX data source.

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

Syntax

'宣言
Function GetUnsupportedReason ( _
    source As Guid, _
    command As CommandID, _
    context As Object _
) As String
'使用
Dim instance As IVsDataProviderDynamicSupport
Dim source As Guid
Dim command As CommandID
Dim context As Object
Dim returnValue As String

returnValue = instance.GetUnsupportedReason(source, _
    command, context)

string GetUnsupportedReason(
    Guid source,
    CommandID command,
    Object context
)

String^ GetUnsupportedReason(
    Guid source, 
    CommandID^ command, 
    Object^ context
)

function GetUnsupportedReason(
    source : Guid, 
    command : CommandID, 
    context : Object
) : String

Parameters

source
Type: System.Guid

A DDEX data source identifier.

command
Type: System.ComponentModel.Design.CommandID

A command identifying the operation.

context
Type: System.Object

An object representing the context in which the operation exists.

Return Value

Type: System.String

A localized string describing why the specified operation is not supported, if the operation is in fact not supported; otherwise, a null reference (Nothing in Visual Basic).

Exceptions

Exception	Condition
ArgumentNullException	The command parameter is a null reference (Nothing in Visual Basic).
ArgumentException	The context parameter is not an expected value for the specified operation.

Remarks

This method enables DDEX providers to return a specific reason that an operation is not supported. DDEX clients can display this reason to the user.

Examples

The following code demonstrates how to implement this method to return a useful message when a Deploy command on a connection node in the data explorer is not supported.

using System;
using System.ComponentModel.Design;
using Microsoft.Win32;
using Microsoft.VisualStudio.Data.Core;
using Microsoft.VisualStudio.Data.Services;

public class MyProviderDynamicSupport2 : IVsDataProviderDynamicSupport
{
    private static readonly CommandID DeployCommand =
        new CommandID(new Guid("6535F307-2083-4cbb-B2FA-11F2DCD69DAF"), 25);

    public bool IsProviderSupported
    {
        get
        {
            return true;
        }
    }

    public bool IsSourceSupported(Guid source)
    {
        return true;
    }

    public bool IsOperationSupported(
        Guid source, CommandID command, object context)
    {
        if (command == null)
        {
            throw new ArgumentNullException("command");
        }
        if (command.Equals(DeployCommand))
        {
            IVsDataExplorerConnection explorerConnection =
                context as IVsDataExplorerConnection;
            if (explorerConnection == null)
            {
                throw new ArgumentException();
            }
            RegistryKey key = Registry.LocalMachine.OpenSubKey(
                @"SOFTWARE\Company\DeployTechnology");
            if (key == null)
            {
                return false;
            }
            key.Close();
        }
        return true;
    }

    public string GetUnsupportedReason(
        Guid source, CommandID command, object context)
    {
        if (command == null)
        {
            throw new ArgumentNullException("command");
        }
        if (command.Equals(DeployCommand) &&
            !IsOperationSupported(source, command, context))
        {
            // Note: This string should be localized
            return "In order to deploy a database you need to install our deployment technology.";
        }
        return null;
    }
}

Permissions

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.