Making Property Handler for my application to add custom properties to a file format

Question

I wanted to add custom properties for my application file type, just like Microsoft Word file tyep .docx has properties on Details Pane in vista and window 7 that show author property and etc trying to do the same for my application but have no clue yet. working in .net2.0 .i dont know what i am doing wrong,

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices.ComTypes;
using Microsoft.Win32;

namespace TestShell
{
    [ComImport]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    [Guid("b7d14566-0509-4cce-a71f-0a554233bd9b")]
    interface IInitializeWithFile
    {
        [PreserveSig]
        int Initialize([MarshalAs(UnmanagedType.LPWStr)] string pszFilePath, uint grfMode);
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PROPERTYKEY
    {
        public Guid fmtid;
        public UIntPtr pid;
    }

    [ComImport]
    [Guid("c8e2d566-186e-4d49-bf41-6909ead56acc")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    interface IPropertyStoreCapabilities
    {
        [PreserveSig]
        int IsPropertyWritable([In] ref PROPERTYKEY key);
    }

    [ComImport]
    [Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    interface IPropertyStore
    {
        [PreserveSig]
        int GetCount([Out] out uint cProps);
        [PreserveSig]
        int GetAt([In] uint iProp, out PROPERTYKEY pkey);
        [PreserveSig]
        int GetValue([In] ref PROPERTYKEY key, out PropVariant pv);
        [PreserveSig]
        int SetValue([In] ref PROPERTYKEY key, [In] ref object pv);
        [PreserveSig]
        int Commit();
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct PropVariant
    {
        public short variantType;
        public short Reserved1, Reserved2, Reserved3;
        public IntPtr pointerValue;
    }


    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.None)]
    [ProgId("TestShell.PropertyHandler")]
    [Guid("9BC59AF4-41E3-49B1-9A62-17F4C92D081F")]
    public class PropertyHandler : IInitializeWithFile, IPropertyStore, IPropertyStoreCapabilities
    {
        private const int S_OK = 0, S_FALSE = 1;

        private string path = null;

        public int Initialize(string pszFilePath, uint grfMode)
        {
            System.Windows.Forms.MessageBox.Show(pszFilePath);
            path = pszFilePath;
            return S_OK;
        }

        public int IsPropertyWritable(ref PROPERTYKEY key)
        {
            System.Windows.Forms.MessageBox.Show("Writable");
            return S_OK;
        }

        public int GetCount(out uint cProps)
        {
            System.Windows.Forms.MessageBox.Show("GetCount");
            cProps = 1;
            return S_OK;
        }

        public int GetAt(uint iProp, out PROPERTYKEY pkey)
        {
            System.Windows.Forms.MessageBox.Show(iProp.ToString());
            pkey = new PROPERTYKEY();
            pkey.fmtid = PKEY_Title;
            pkey.pid = (UIntPtr)0x2;
            return S_OK;
        }

        private Guid PKEY_Title = new Guid("F29F85E0-4FF9-1068-AB91-08002B27B3D9");

        public int GetValue(ref PROPERTYKEY key, out PropVariant pv)
        {
            System.Windows.Forms.MessageBox.Show(key.fmtid.ToString());
            pv = new PropVariant();
            if (key.fmtid == PKEY_Title) {
                pv.variantType = 31;
                pv.pointerValue = Marshal.StringToHGlobalUni("Test");
                return S_OK;
            } else {
                pv.variantType = 0; //VT_EMPTY
                pv.pointerValue = IntPtr.Zero;
                return S_OK;
            }
        }

        public int SetValue(ref PROPERTYKEY key, ref object pv)
        {
            return S_OK;
        }

        public int Commit()
        {
            return S_OK;
        }

        [ComRegisterFunctionAttribute]
        public static void RegisterFunction(Type t)
        {
            try {
                RegistryKey regHKCR = Registry.ClassesRoot;
                regHKCR = regHKCR.CreateSubKey(".test");
                regHKCR.SetValue(null, "TestShell.PropertyHandler");

                regHKCR = Registry.ClassesRoot;
                regHKCR = regHKCR.CreateSubKey("CLSID\\{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");
                regHKCR.SetValue(null, "Test Property");
                regHKCR.SetValue("ManualSafeSave", 1);
                regHKCR = regHKCR.CreateSubKey("InProcServer32");
                regHKCR.SetValue(null, System.Reflection.Assembly.GetExecutingAssembly().Location);
                regHKCR.SetValue("ThreadingModel", "Apartment");

                RegistryKey regHKLM;
                regHKLM = Registry.LocalMachine.CreateSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\PropertySystem\\PropertyHandlers\\.test");
                regHKLM.SetValue(null, "{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");
                regHKLM = Registry.LocalMachine.CreateSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Shell Extensions\\Approved");
                regHKLM.SetValue("{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}", "Test Property");
            } catch (Exception ex) {
#if DEBUG
                System.Windows.Forms.MessageBox.Show(ex.Message + System.Environment.NewLine + ex.StackTrace);
#endif
            }
#if DEBUG
            //SHShellRestart();
#endif
        }

        [ComUnregisterFunctionAttribute]
        public static void UnRegisterFunction(Type t)
        {
            try {
                RegistryKey regHKCR = Registry.ClassesRoot;
                regHKCR.DeleteSubKey(".test");
                regHKCR.DeleteSubKeyTree("CLSID\\{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");

                RegistryKey regHKLM = Registry.LocalMachine;
                regHKLM.DeleteSubKeyTree("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\PropertySystem\\PropertyHandlers\\.test");
                regHKLM = Registry.LocalMachine.OpenSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Shell Extensions\\Approved", true);
                regHKLM.DeleteValue("{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");
            } catch (Exception ex) {
#if DEBUG
                System.Windows.Forms.MessageBox.Show(ex.Message + System.Environment.NewLine + ex.StackTrace);
#endif
            }
#if DEBUG
            //SHShellRestart();
#endif
        }

#if DEBUG
        [DllImport("user32.dll")]
        static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
        [DllImport("user32.dll")]
        static extern bool PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
        [DllImport("shell32.dll")]
        static extern IntPtr ShellExecute(
            IntPtr hwnd, string lpOperation, string lpFile,
            string lpParameters, string lpDirectory, int nShowCmd);
        private static void SHShellRestart()
        {
            PostMessage(FindWindow("Progman", null), 0x0012, IntPtr.Zero, IntPtr.Zero);
            ShellExecute(IntPtr.Zero, null, "explorer.exe", null, null, 5);
            return;
        }
#endif
    }
}

do i need to instatiate the propert handler class too. if yes than how should i do it, any ideas someone, i have been stuck here for 3 days now. when i register this dll the property handler gets registered but no custom property appears on the .test file.

Answer 1

i have managed to register my property handler as COM and explorer is calling my code when i click on file tyep (.test) against whcih i am trying to custom add properties. Below is the code, now the only thing left is to somehow create new properties, i have no idea how to create new properties, any help is appreciated

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices.ComTypes;
using Microsoft.Win32;
using System.Windows.Forms;

namespace TestShell
{
  [ComImport]
  [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
  [Guid("b7d14566-0509-4cce-a71f-0a554233bd9b")]
  interface IInitializeWithFile
  {
    [PreserveSig]
    int Initialize([MarshalAs(UnmanagedType.LPWStr)] string pszFilePath, uint grfMode);
  }

  [StructLayout(LayoutKind.Sequential)]
  public struct PROPERTYKEY
  {
    public Guid fmtid;
    public UIntPtr pid;
  }

  [ComImport]
  [Guid("c8e2d566-186e-4d49-bf41-6909ead56acc")]
  [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
  interface IPropertyStoreCapabilities
  {
    [PreserveSig]
    int IsPropertyWritable([In] ref PROPERTYKEY key);
  }

  [ComImport]
  [Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99")]
  [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
  interface IPropertyStore
  {
    [PreserveSig]
    int GetCount([Out] out uint cProps);
    [PreserveSig]
    int GetAt([In] uint iProp, out PROPERTYKEY pkey);
    [PreserveSig]
    int GetValue([In] ref PROPERTYKEY key, out PropVariant pv);
    [PreserveSig]
    int SetValue([In] ref PROPERTYKEY key, [In] ref object pv);
    [PreserveSig]
    int Commit();
  }

  [StructLayout(LayoutKind.Sequential)]
  public struct PropVariant
  {
    public short variantType;
    public short Reserved1, Reserved2, Reserved3;
    public IntPtr pointerValue;
  }


  [ComVisible(true)]
  [ClassInterface(ClassInterfaceType.None)]
  [ProgId("TestShell.PropertyHandler")]
  [Guid("9BC59AF4-41E3-49B1-9A62-17F4C92D081F")]
  public class PropertyHandler : IInitializeWithFile, IPropertyStore, IPropertyStoreCapabilities
  {
    private const int S_OK = 0, S_FALSE = 1;

    private string path = null;


    public int Initialize(string pszFilePath, uint grfMode)
    {
      //System.Windows.Forms.MessageBox.Show(pszFilePath);
      path = pszFilePath;
      return S_OK;
    }

    public int IsPropertyWritable(ref PROPERTYKEY key)
    {
      //System.Windows.Forms.MessageBox.Show("Writable");
      return S_OK;
    }

    public int GetCount(out uint cProps)
    {
      //System.Windows.Forms.MessageBox.Show("GetCount");
      cProps = 1;
      return S_OK;
    }

    public int GetAt(uint iProp, out PROPERTYKEY pkey)
    {
      System.Windows.Forms.MessageBox.Show(iProp.ToString());
      pkey = new PROPERTYKEY();
      pkey.fmtid = PKEY_Title;
      pkey.pid = (UIntPtr)0x2;
      return S_OK;
    }

    private Guid PKEY_Title = new Guid("F29F85E0-4FF9-1068-AB91-08002B27B3D9");

    public int GetValue(ref PROPERTYKEY key, out PropVariant pv)
    {
      System.Windows.Forms.MessageBox.Show(key.fmtid.ToString());
      pv = new PropVariant();
      if (key.fmtid == PKEY_Title)
      {
        pv.variantType = 31;
        pv.pointerValue = Marshal.StringToHGlobalUni("Test");
        return S_OK;
      }
      else
      {
        pv.variantType = 0; //VT_EMPTY
        pv.pointerValue = IntPtr.Zero;
        return S_OK;
      }
    }

    public int SetValue(ref PROPERTYKEY key, ref object pv)
    {
      return S_OK;
    }

    public int Commit()
    {
      return S_OK;
    }



    [ComRegisterFunctionAttribute]
    public static void RegisterFunction(Type t)
    {

      try
      {
        RegistryKey regHKCR = Registry.ClassesRoot;
        regHKCR = regHKCR.CreateSubKey(".test");
        regHKCR.SetValue(null, "TestShell.PropertyHandler");

        regHKCR = Registry.ClassesRoot;
        regHKCR = regHKCR.CreateSubKey("CLSID\\{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");
        regHKCR.SetValue(null, "Test Property");
        regHKCR.SetValue("ManualSafeSave", 1);
        regHKCR.SetValue("Title", 2);
        regHKCR.SetValue("Whatever", 3);
        regHKCR = regHKCR.CreateSubKey("InProcServer32");

        regHKCR.SetValue(null, @"C:\Windows\System32\mscoree.dll");
        //regHKCR.SetValue(null, System.Reflection.Assembly.GetExecutingAssembly().Location);
        regHKCR.SetValue("ThreadingModel", "Apartment");

        RegistryKey regHKLM;
        regHKLM = Registry.LocalMachine.CreateSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\PropertySystem\\PropertyHandlers\\.test");
        regHKLM.SetValue(null, "{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");
        regHKLM = Registry.LocalMachine.CreateSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Shell Extensions\\Approved");
        regHKLM.SetValue("{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}", "Test Property");
        //SHShellRestart();---------------------------------------------------------------------------------------------

        // string propertyID = "VolumeName";
        // //PROPSPEC propSpec = new PROPSPEC();
        // //propSpec.ulKind = 0;
        //// propSpec.__unnamed.lpwstr = (char*)Marshal.StringToCoTaskMemUni(propertyID);

        // PropVariant propVar = new PropVariant();
        // propVar.__unnamed.__unnamed.__unnamed.bstrVal = (char*)Marshal.StringToCoTaskMemUni(value);

        //   //delcare un safe variables
        //   PROPSPEC[] rgSpecs = new PROPSPEC[1];
        //   rgSpecs[0] = propSpec;

        //   PROPVARIANT[] rgVar = new PROPVARIANT[1];
        //   rgVar[0] = propVar;

        //   object val = value;
        //   ppPropStg.WriteMultiple(1, ref propSpec, ref val, 3);
        //   ppPropStg.Commit(0x8);
        //   fDataDiscWriter.SetJolietProperties(ppPropStg);

      }




      catch (Exception ex)//HKEY_CLASSES_ROOT\CLSID\{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}\Implemented Categories\{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}
      {
#if DEBUG
        System.Windows.Forms.MessageBox.Show(ex.Message + System.Environment.NewLine + ex.StackTrace);
#endif
      }
#if DEBUG
      //SHShellRestart();
#endif
    }

    [ComUnregisterFunctionAttribute]
    public static void UnRegisterFunction(Type t)
    {
      try
      {
        RegistryKey regHKCR = Registry.ClassesRoot;
        regHKCR.DeleteSubKey(".test");
        regHKCR.DeleteSubKeyTree("CLSID\\{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");

        RegistryKey regHKLM = Registry.LocalMachine;
        regHKLM.DeleteSubKeyTree("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\PropertySystem\\PropertyHandlers\\.test");
        regHKLM = Registry.LocalMachine.OpenSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Shell Extensions\\Approved", true);
        regHKLM.DeleteValue("{9BC59AF4-41E3-49B1-9A62-17F4C92D081F}");
      }
      catch (Exception ex)
      {
#if DEBUG
        System.Windows.Forms.MessageBox.Show(ex.Message + System.Environment.NewLine + ex.StackTrace);
#endif
      }
#if DEBUG
      //SHShellRestart();
#endif
    }

//#if DEBUG
    [DllImport("user32.dll")]
    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
    [DllImport("user32.dll")]
    static extern bool PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
    [DllImport("shell32.dll")]
    static extern IntPtr ShellExecute(
      IntPtr hwnd, string lpOperation, string lpFile,
      string lpParameters, string lpDirectory, int nShowCmd);
    private static void SHShellRestart()
    {
      PostMessage(FindWindow("Progman", null), 0x0012, IntPtr.Zero, IntPtr.Zero);
      ShellExecute(IntPtr.Zero, null, "explorer.exe", null, null, 5);
      return;
    }
//#endif
  }
}

his code is prety much from msdn link d except there was a mistake in the code coz of which the handler was not being register, In the InProc32 registy key the value should be the path to mscoree.dll, when i added that the application started working.

I know this much the custom properties will be added using 2 ways. just a guess 1 - IPropertyStrore.SetValue 2 - Adding registry key entries to F29F85E0-4FF9-1068-AB91-08002B27B3D9 key in registry

Answer 2

As Jakob mentioned, take a look at Windows API Code Pack (the old link is deprecated). Here is a simple code snippet using it:

public static void PreventPinning(Window window)
{
    var preventPinningProperty = new PropertyKey(new Guid("9F4C2855-9F79-4B39-A8D0-E1D42DE1D5F3"), 9);
    WindowProperties.SetWindowProperty(window, preventPinningProperty, "1");
}

Example above is setting System.AppUserModel.PreventPinning defined by its Guid and PropertyId.

Answer 3

Have you had a look at the Windows API Code Pack ? I am not sure if the Code Pack can add properties to file types but I know it can be used for editing existing properties so it may be worth a look.

Answer 4

Alternative:

If I understand your problem correctly, this might be what you are looking for

How to set custom attributes / file properties on a file in C# .Net - by Rod Howarth

While Saving the file, you could just set the custom property on it.