Shell Extension stages.

using System;

using System.Drawing;

using System.Runtime.InteropServices;

using ExtractImageInterop;

 

namespace WellFormed

{

  /// <summary>

  /// Summary description for ThumbExt.

  /// </summary>

  [ClassInterface(ClassInterfaceType.None),

  Guid("E134E0A2-5682-41d4-AF22-6F516844C094")]

  public class ThumbExt : IExtractImage, IPersistFile

  {

 

 

    public ThumbExt()

    {

      //

      // TODO: Add constructor logic here

      //

    }

 

    #region IExtractImage Members

 

    public void Extract(System.IntPtr phBmpThumbnail)

    {

    }

 

    public void GetLocation(string pszPathBuffer, uint cch, ref uint pdwPriority, ref tagSIZE prgSize, uint dwRecClrDepth, ref uint pdwFlags)

    {

    }

 

    #endregion

 

    #region IPersistFile Members

 

    public void SaveCompleted(string pszFileName)

    {

    }

 

    public void GetCurFile(out string ppszFileName)

    {

    }

 

    public void GetClassID(out Guid pClassID)

    {

    }

 

    public void Load(string pszFileName, uint dwMode)

    {

    }

 

    public void IsDirty()

    {

    }

 

    public void Save(string pszFileName, int fRemember)

    {

    }

 

    #endregion

  }

}

 

In stage 1 we have a project that imports the interop DLL, has a GUID, has the stubs of the interface implementations and has been configured by right clicking on the project, selecting Properties and enabling the option to "Register for COM interop" as seen in the following image.

 

Stage 2. The full implementation

using System;

using System.Drawing;

using System.Runtime.InteropServices;

using ExtractImageInterop;

 

namespace WellFormed

{

  /// <summary>

  /// Summary description for ThumbExt.

  /// </summary>

  [ClassInterface(ClassInterfaceType.None),

  Guid("E134E0A2-5682-41d4-AF22-6F516844C094")]

  public class ThumbExt : IExtractImage, IPersistFile

  {

 

    string filename;

    Size _size;

 

    public ThumbExt()

    {

      //

      // TODO: Add constructor logic here

      //

    }

    #region IExtractImage Members

 

    public void Extract(System.IntPtr phBmpThumbnail)

    {

      ColorShape cs=ColorShape.Load(filename);

      Bitmap bm=new Bitmap(_size.Width,_size.Height);

      Graphics g=Graphics.FromImage(bm);

      cs.Draw(g,new Rectangle(0,0,bm.Width,bm.Height));

      Marshal.WriteIntPtr(phBmpThumbnail,bm.GetHbitmap(Color.White));

      bm.Dispose();

    }

 

    public void GetLocation(string pszPathBuffer, uint cch, ref uint pdwPriority, ref tagSIZE prgSize, uint dwRecClrDepth, ref uint pdwFlags)

    {

      _size=new Size(prgSize.cx,prgSize.cy);

      pdwPriority=0x10000000u; //normal priority

    }

 

    #endregion

 

    #region IPersistFile Members

 

    public void SaveCompleted(string pszFileName)

    {

      throw new NotImplementedException();

    }

 

    public void GetCurFile(out string ppszFileName)

    {

      throw new NotImplementedException();

    }

 

    public void GetClassID(out Guid pClassID)

    {

      throw new NotImplementedException();

    }

 

    public void Load(string pszFileName, uint dwMode)

    {

      this.filename=pszFileName;

    }

 

    public void IsDirty()

    {

      throw new NotImplementedException();

    }

 

    public void Save(string pszFileName, int fRemember)

    {

      throw new NotImplementedException();

    }

 

    #endregion

  }

}

 

 

Imports System

Imports System.Drawing

Imports System.Runtime.InteropServices

Imports ExtractImageInterop

Imports GraphicsDLLVB

 

 

Namespace WellFormed

 

  '' <summary>

  '' Summary description for ThumbExt.

  '' </summary>

  <ClassInterface(ClassInterfaceType.None), _

  Guid("E134E0A2-5682-41d4-AF22-6F516844C095")> _

  Public Class ThumbExt

    Implements IExtractImage, IPersistFile

 

    Private filename As String

    Private _size As Size

 

    Public Sub New()

    End Sub

 

#Region "IExtractImage Members"

 

    Public Sub Extract(ByVal phBmpThumbnail As System.IntPtr) Implements IExtractImage.Extract

    End Sub

 

    Public Sub GetLocation(ByVal pszPathBuffer As String, ByVal cch As System.UInt32, ByRef pdwPriority As System.UInt32, ByRef prgSize As tagSIZE, ByVal dwRecClrDepth As System.UInt32, ByRef pdwFlags As System.UInt32) Implements IExtractImage.GetLocation

    End Sub

 

#End Region

 

#Region "IPersistFile Members"

 

    Public Sub SaveCompleted(ByVal pszFileName As String) Implements ExtractImageInterop.IPersistFile.SaveCompleted

    End Sub

 

    Public Sub GetCurFile(ByRef ppszFileName As String) Implements ExtractImageInterop.IPersistFile.GetCurFile

    End Sub

 

    Public Sub GetClassID(ByRef pClassID As System.Guid) Implements ExtractImageInterop.IPersistFile.GetClassID

    End Sub

 

    Public Sub Load(ByVal pszFileName As String, ByVal dwMode As UInt32) Implements ExtractImageInterop.IPersistFile.Load

    End Sub

 

    Public Sub IsDirty() Implements IPersistFile.IsDirty

    End Sub

 

    Public Sub Save(ByVal pszFileName As String, ByVal fRemember As Integer) Implements ExtractImageInterop.IPersistFile.Save

    End Sub

 

#End Region

 

#Region "IPersist implementation"

    Public Sub GetClassID1(ByRef pClassID As System.Guid) Implements ExtractImageInterop.IPersist.GetClassID

    End Sub

#End Region

 

  End Class

end namespace

 

In stage 1 we have a project that imports the interop DLL, has a GUID, has the stubs of the interface implementations and has been configured by right clicking on the project, selecting Properties and enabling the option to "Register for COM interop" as seen in the following image.

 

Stage 2. The full implementation

Imports System

Imports System.Drawing

Imports System.Runtime.InteropServices

Imports ExtractImageInterop

Imports GraphicsDLLVB

 

 

Namespace WellFormed

 

  '' <summary>

  '' Summary description for ThumbExt.

  '' </summary>

  <ClassInterface(ClassInterfaceType.None), _

  Guid("E134E0A2-5682-41d4-AF22-6F516844C095")> _

  Public Class ThumbExt

    Implements IExtractImage, IPersistFile

 

    Private filename As String

    Private _size As Size

 

    Public Sub New()

    End Sub

 

#Region "IExtractImage Members"

 

    Public Sub Extract(ByVal phBmpThumbnail As System.IntPtr) Implements IExtractImage.Extract

      Dim cs As ColorShape = ColorShape.Load(filename)

      Dim bm As New Bitmap(_size.Width, _size.Height)

      Dim g As Graphics = Graphics.FromImage(bm)

      cs.Draw(g, New Rectangle(0, 0, bm.Width, bm.Height))

      Marshal.WriteIntPtr(phBmpThumbnail, bm.GetHbitmap(Color.White))

      bm.Dispose()

    End Sub

 

    Public Sub GetLocation(ByVal pszPathBuffer As String, ByVal cch As System.UInt32, ByRef pdwPriority As System.UInt32, ByRef prgSize As tagSIZE, ByVal dwRecClrDepth As System.UInt32, ByRef pdwFlags As System.UInt32) Implements IExtractImage.GetLocation

      _size = New Size(prgSize.cx, prgSize.cy)

      pdwPriority = Convert.ToUInt32(&H10000000) 'normal priority

    End Sub

 

#End Region

 

#Region "IPersistFile Members"

 

    Public Sub SaveCompleted(ByVal pszFileName As String) Implements ExtractImageInterop.IPersistFile.SaveCompleted

      Throw New NotImplementedException

    End Sub

 

    Public Sub GetCurFile(ByRef ppszFileName As String) Implements ExtractImageInterop.IPersistFile.GetCurFile

      Throw New NotImplementedException

    End Sub

 

    Public Sub GetClassID(ByRef pClassID As System.Guid) Implements ExtractImageInterop.IPersistFile.GetClassID

      Throw New NotImplementedException

    End Sub

 

    Public Sub Load(ByVal pszFileName As String, ByVal dwMode As UInt32) Implements ExtractImageInterop.IPersistFile.Load

      Me.filename = pszFileName

    End Sub

 

    Public Sub IsDirty() Implements IPersistFile.IsDirty

      Throw New NotImplementedException

    End Sub

 

    Public Sub Save(ByVal pszFileName As String, ByVal fRemember As Integer) Implements ExtractImageInterop.IPersistFile.Save

      Throw New NotImplementedException

    End Sub

 

#End Region

 

#Region "IPersist implementation"

    Public Sub GetClassID1(ByRef pClassID As System.Guid) Implements ExtractImageInterop.IPersist.GetClassID

      Throw New NotImplementedException

    End Sub

#End Region

 

  End Class

end namespace