Window explorer is freezing when open

Question

I need to open the specific folder for a file and I am doing it with:

file = Directory.GetFiles(filepath,Filename,
                          SearchOption.AllDirectories).FirstOrDefault()

   Process.Start("explorer.exe", "/select," & file.ToString)

This code is immediately opening the folder which is already fully loaded, but it doesnt seem enabled, endeed I cant do any action in it. The form is not freezing. Thanks

Answer 1

I'll give you an answer in two parts...

Firstly, if the GetFiles() call takes to long and freezes the form (which doesn't seem to be the current problem), you should do the following:

• Use EnumerateFiles() instead because in this case, FirstOrDefault() will return immediately after finding a matching file, unlike GetFiles() which will get all the files first before calling FirstOrDefault().

• Wrap the call to EnumerateFiles() in a Task.Run() to execute it on a worker thread in case the search takes a little too long:

  ' Or: 
  ' Private Async Sub SomeEventHandler() 
  Private Async Function ParentMethod() As Task
      Dim filePath As String = Await Task.Run(
          Function()
              Return Directory.EnumerateFiles(dirPath, FileName, SearchOption.AllDirectories).
                               FirstOrDefault()
          End Function)
      ' TODO: Use `filePath` to open the folder and select the file.
  End Function
  

Secondly, do not use Process.Start("explorer.exe", "/select") because a) it starts a new Explorer.exe process rather than opening the directory in the current one, b) it seems to be causing you some issues, and c) it has some limitations.

Instead, use the approach demonstrated in the answer linked in point (c) above. The code is in C# but it can be easily converted to VB. Here's the VB version of the code (with an additional overload).

Add the following class to your project:

Imports System.IO
Imports System.Runtime.InteropServices

Public Class NativeMethods
    <DllImport("shell32.dll", SetLastError:=True)>
    Private Shared Function SHOpenFolderAndSelectItems(
            pidlFolder As IntPtr, cidl As UInteger,
            <[In], MarshalAs(UnmanagedType.LPArray)> apidl As IntPtr(),
            dwFlags As UInteger) As Integer
    End Function

    <DllImport("shell32.dll", SetLastError:=True)>
    Private Shared Sub SHParseDisplayName(
            <MarshalAs(UnmanagedType.LPWStr)> name As String,
            bindingContext As IntPtr, <Out> ByRef pidl As IntPtr,
            sfgaoIn As UInteger, <Out> ByRef psfgaoOut As UInteger)
    End Sub

    Public Shared Sub OpenFolderAndSelectFile(filePath As String)
        Dim dirPath As String = Path.GetDirectoryName(filePath)
        Dim fileName As String = Path.GetFileName(filePath)
        OpenFolderAndSelectFile(dirPath, fileName)
    End Sub

    Public Shared Sub OpenFolderAndSelectFile(dirPath As String, fileName As String)
        Dim nativeFolder As IntPtr
        Dim psfgaoOut As UInteger
        SHParseDisplayName(dirPath, IntPtr.Zero, nativeFolder, 0, psfgaoOut)

        If nativeFolder = IntPtr.Zero Then
            ' Log error, can't find folder
            Return
        End If

        Dim nativeFile As IntPtr
        SHParseDisplayName(Path.Combine(dirPath, fileName),
                           IntPtr.Zero, nativeFile, 0, psfgaoOut)

        Dim fileArray As IntPtr()
        If nativeFile = IntPtr.Zero Then
            ' Open the folder without the file selected if we can't find the file
            fileArray = New IntPtr(-1) {}
        Else
            fileArray = New IntPtr() {nativeFile}
        End If

        SHOpenFolderAndSelectItems(nativeFolder, CUInt(fileArray.Length), fileArray, 0)

        Marshal.FreeCoTaskMem(nativeFolder)
        If nativeFile <> IntPtr.Zero Then
            Marshal.FreeCoTaskMem(nativeFile)
        End If
    End Sub
End Class

Then, you can easily call it like this:

NativeMethods.OpenFolderAndSelectFile(filePath)

Some additional notes:

• You should choose meaningful variable names. filePath should refer to the path of a file. If you want to refer to a folder/directory path, use something like dirPath or folderPath instead.

• You don't need to call .ToString() on a variable that's already of a String type.

Answer 2

I would change the variable name file to something else. Maybe foundFile. After all File is the name of a class in System.IO and vb.net is not case sensitive. Your code works fine for me with the variable name change. Also got rid of the .ToString. I used .EnumerateFiles as commented by @jmcilhinney in the question you deleted. I purposely chose a path with all sorts of strange characters and it still worked.

Private Sub OPCode()
    Dim filepath = "C:\Users\xxxx\Documents\TextNotes\Dogs & Cats (Pets)"
    Dim Filename = "Specialty Vets.txt"
    Dim foundFile = Directory.EnumerateFiles(filepath, Filename,
                      IO.SearchOption.AllDirectories).FirstOrDefault()
    Process.Start("explorer.exe", "/select," & foundFile)
End Sub