C# Signature:

[DllImport("shell32.dll", SetLastError=true)]
public static extern int SHOpenFolderAndSelectItems(IntPtr pidlFolder, uint cidl, [In, MarshalAs(UnmanagedType.LPArray)] IntPtr[] apidl, uint dwFlags);

VB Signature:

  <DllImport("shell32.dll", ExactSpelling:=True, SetLastError:=True, CharSet:=CharSet.Unicode)> _
  Public Shared Function SHOpenFolderAndSelectItems(ByVal pidlFolder As IntPtr, ByVal cidl As UInteger, <MarshalAs(UnmanagedType.LPArray)> ByVal apidl() As IntPtr, ByVal dwFlags As UInteger) As Integer
  End Function

User-Defined Types:

None.

Alternative Managed API:

Do you know one? Please contribute it!

Process.Start("explorer.exe", "\"/select,c:\\windows\\system32\\calc.exe\"");

Notes:

None.

Tips & Tricks:

Please add some!

Usage:

  If ExplorerSelectItems.SetFolder("c:\windows\system32\") Then
    ExplorerSelectItems.AddFile("calc.exe")
    ExplorerSelectItems.AddFile("cacls.exe")
    ExplorerSelectItems.AddFile("cabview.dll")
    ExplorerSelectItems.AddFile("cabinet.dll")
    ExplorerSelectItems.Commit()
  End If

Sample Code:

  Imports System.Runtime.InteropServices
  Imports System.Security.Permissions
  Imports System.IO

  Public NotInheritable Class ExplorerSelectItems

    Private Shared pidlList As New List(Of IntPtr)
    Private Shared pidlFolder As IntPtr = IntPtr.Zero
    Private Shared _folderPath As String = String.Empty

    Private Sub New()
    End Sub

    ''' <summary>
    ''' Sets the parent directory containing the files that will be selected.
    ''' </summary>
    <SecurityPermission(SecurityAction.LinkDemand, Flags:=SecurityPermissionFlag.UnmanagedCode)> _
    Public Shared Function SetFolder(ByVal folderPath As String) As Boolean
    FreeList()
    If SafeNativeMethods.SHParseDisplayName(folderPath, IntPtr.Zero, pidlFolder, 0, 0) = 0 Then
        _folderPath = folderPath
        Return True
    End If
    Return False
    End Function

    ''' <summary>
    ''' Adds a single file to be selected.
    ''' </summary>
    <SecurityPermission(SecurityAction.LinkDemand, Flags:=SecurityPermissionFlag.UnmanagedCode)> _
    Public Shared Sub AddFile(ByVal fileName As String)
    Dim pidl As IntPtr = IntPtr.Zero
    If pidlFolder = IntPtr.Zero Then
        Return
    End If
    If SafeNativeMethods.SHParseDisplayName(Path.Combine(_folderPath, fileName), IntPtr.Zero, pidl, 0, 0) = 0 Then
        pidlList.Add(pidl)
    End If
    End Sub

    ''' <summary>
    ''' Opens and selects all files. In addition releases all resources.
    ''' </summary>
    <SecurityPermission(SecurityAction.LinkDemand, Flags:=SecurityPermissionFlag.UnmanagedCode)> _
    Public Shared Sub Commit()
    Dim pidl() As IntPtr
    If pidlFolder = IntPtr.Zero Then
        Return
    End If
    pidl = pidlList.ToArray
    SafeNativeMethods.SHOpenFolderAndSelectItems(pidlFolder, pidl.Length, pidl, 0)
    FreeList()
    End Sub

    Private Shared Sub FreeList()
    If pidlFolder <> IntPtr.Zero Then
        Marshal.FreeCoTaskMem(pidlFolder)
        pidlFolder = IntPtr.Zero
    End If
    For Each pidl In pidlList
        Marshal.FreeCoTaskMem(pidl)
    Next
    pidlList.Clear()
    End Sub

  End Class

  Friend NotInheritable Class SafeNativeMethods
    <DllImport("shell32.dll", ExactSpelling:=True, SetLastError:=True, CharSet:=CharSet.Unicode)> _
    Public Shared Function SHParseDisplayName(<MarshalAs(UnmanagedType.LPWStr)> ByVal pszName As String, ByVal pbc As IntPtr, ByRef ppidl As IntPtr, ByVal sfgaoIn As UInteger, ByRef psfgaoOut As UInteger) As Integer
    End Function
    <DllImport("shell32.dll", ExactSpelling:=True, SetLastError:=True, CharSet:=CharSet.Unicode)> _
    Public Shared Function SHOpenFolderAndSelectItems(ByVal pidlFolder As IntPtr, ByVal cidl As UInteger, <MarshalAs(UnmanagedType.LPArray)> ByVal apidl() As IntPtr, ByVal dwFlags As UInteger) As Integer
    End Function
  End Class