Ejemplo de código AccessDbProviderSample02

En el siguiente código se muestra la implementación del proveedor de PowerShell de Windows descrito en Creación de un proveedor de unidades de Windows PowerShell. Esta implementación crea una ruta de acceso, realiza una conexión a una base de datos de Access y, a continuación, quita la unidad.

Nota:

Puede descargar el archivo de origen de C# (AccessDBSampleProvider02.cs) para este proveedor mediante el Kit de desarrollo de software de Microsoft Windows para Windows Vista y microsoft .NET Framework 3.0 Runtime Components. Para obtener instrucciones de descarga, consulte Cómo instalar Windows PowerShell y Descargar el SDK de Windows PowerShell. Los archivos de código fuente descargados están disponibles en el directorio<>. Para obtener más información sobre otras implementaciones del proveedor de Windows PowerShell, consulte Diseño del proveedor de Windows PowerShell.

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 Windows PowerShell

del SDK de Windows PowerShell