Ejemplo de código AccessDbProviderSample02

El siguiente código muestra la implementación del proveedor PowerShell de Windows descrita en Creando un proveedor de unidades Windows PowerShell. Esta implementación crea un camino, conecta con una base de datos Access y luego elimina la unidad.

Nota:

Puedes descargar el archivo fuente en C# (AccessDBSampleProvider02.cs) de este proveedor utilizando el Microsoft Windows Software Development Kit para Windows Vista y Microsoft .NET Framework 3.0 Runtime Components. Para las instrucciones de descarga, consulta Cómo instalar Windows PowerShell y descargar el SDK de Windows PowerShell. Los archivos fuente descargados están disponibles en el <directorio de Ejemplos> de PowerShell. Para más información sobre otras implementaciones de proveedores de Windows PowerShell, consulte Diseñando su proveedor de PowerShell para Windows.

Ejemplo de código

using System;
using System.IO;
using System.Data;
using System.Data.Odbc;
using System.Management.Automation;
using System.Management.Automation.Provider;
using System.ComponentModel;

namespace Microsoft.Samples.PowerShell.Providers
{
   #region AccessDBProvider

    /// <summary>
   /// A PowerShell Provider which acts upon a access data store.
   /// </summary>
   /// <remarks>
   /// This example only demonstrates the drive overrides
   /// </remarks>
   [CmdletProvider("AccessDB", ProviderCapabilities.None)]
   public class AccessDBProvider : DriveCmdletProvider
   {
       #region Drive Manipulation

       /// <summary>
       /// Create a new drive.  Create a connection to the database file and set
       /// the Connection property in the PSDriveInfo.
       /// </summary>
       /// <param name="drive">
       /// Information describing the drive to add.
       /// </param>
       /// <returns>The added drive.</returns>
       protected override PSDriveInfo NewDrive(PSDriveInfo drive)
       {
           // check if drive object is null
           if (drive == null)
           {
               WriteError(new ErrorRecord(
                   new ArgumentNullException("drive"), 
                   "NullDrive",
                   ErrorCategory.InvalidArgument, 
                   null)
               );
            
               return null;
           }
        
           // check if drive root is not null or empty
           // and if its an existing file
           if (String.IsNullOrEmpty(drive.Root) || (File.Exists(drive.Root) == false))
           {
               WriteError(new ErrorRecord(
                   new ArgumentException("drive.Root"), 
                   "NoRoot",
                   ErrorCategory.InvalidArgument, 
                   drive)
               );
 
               return null;
           }

           // create a new drive and create an ODBC connection to the new drive
           AccessDBPSDriveInfo accessDBPSDriveInfo = new AccessDBPSDriveInfo(drive);

           OdbcConnectionStringBuilder builder = new OdbcConnectionStringBuilder();

           builder.Driver = "Microsoft Access Driver (*.mdb)";
           builder.Add("DBQ", drive.Root);
          
           OdbcConnection conn = new OdbcConnection(builder.ConnectionString);
           conn.Open();
           accessDBPSDriveInfo.Connection = conn;

           return accessDBPSDriveInfo;
       } // NewDrive

       /// <summary>
       /// Removes a drive from the provider.
       /// </summary>
       /// <param name="drive">The drive to remove.</param>
       /// <returns>The drive removed.</returns>
       protected override PSDriveInfo RemoveDrive(PSDriveInfo drive)
       {
           // check if drive object is null
           if (drive == null)
           {
               WriteError(new ErrorRecord(
                   new ArgumentNullException("drive"), 
                   "NullDrive",
                   ErrorCategory.InvalidArgument, 
                   drive)
               );

              return null;
           }

           // close ODBC connection to the drive
           AccessDBPSDriveInfo accessDBPSDriveInfo = drive as AccessDBPSDriveInfo;

           if (accessDBPSDriveInfo == null)
           {
               return null;
           }
           accessDBPSDriveInfo.Connection.Close();
         
           return accessDBPSDriveInfo;
       } // RemoveDrive

       #endregion Drive Manipulation

   } // AccessDBProvider

   #endregion AccessDBProvider

   #region AccessDBPSDriveInfo

   /// <summary>
   /// Any state associated with the drive should be held here.
   /// In this case, it's the connection to the database.
   /// </summary>
   internal class AccessDBPSDriveInfo : PSDriveInfo
   {
       private OdbcConnection connection;

       /// <summary>
       /// ODBC connection information.
       /// </summary>
       public OdbcConnection Connection
       {
           get { return connection; }
           set { connection = value; }
       }

       /// <summary>
       /// Constructor that takes one argument
       /// </summary>
       /// <param name="driveInfo">Drive provided by this provider</param>
       public AccessDBPSDriveInfo(PSDriveInfo driveInfo)
           : base(driveInfo)
       { }

   } // class AccessDBPSDriveInfo

   #endregion AccessDBPSDriveInfo
}

Véase también

Guía del programador de PowerShell para Windows

Windows PowerShell SDK