AccessDbProviderSample02 – kodexempel
Följande kod visar implementeringen av den Windows PowerShell som beskrivs i Skapa en Windows PowerShell-enhetsprovider. Den här implementeringen skapar en sökväg, upprättar en anslutning till en Access-databas och tar sedan bort enheten.
Anteckning
Du kan ladda ned C#-källfilen (AccessDBSampleProvider02.cs) för den här providern med hjälp av Microsoft Windows Software Development Kit för Windows Vista och Microsoft .NET Framework 3.0 Runtime Components. Anvisningar för nedladdning finns i Installera Windows PowerShell och Ladda ned Windows PowerShell SDK. De nedladdade källfilerna är tillgängliga i <PowerShell Samples> katalogen . Mer information om andra Windows PowerShell-providerimplementering finns i Designing Your Windows PowerShell Provider (Utforma din Windows PowerShell provider).
Kodexempel
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
}
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