File Icons and List view - vb.net

Question

How to retrieve file icons associated with the file types and add them with the items of Listview in vb.net
I read about SHGetFileInfo but I didn't understand anything from that
please give me solution or please explain me ho system works with the .net controls in details

Answer 1

Having looked up SHGetFileInfo I can see why you're confused by it, but I think it might be slightly overkill for what I think you're trying to do i.e. enumerating the contents of a folder and adding items to the Listview.
If we have a form that contains a ListView and an ImageList, with the two related by having the ListView's LargeImageList property set to the ImageList, then here's how we put the contents of a folder into the ListView with the icons coming from the associated EXE file for each file.
Imports System.IO
Imports System.Drawing
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim dirInfo As DirectoryInfo
Dim fileInfo As FileInfo
Dim exePath As String
Dim exeIcon As Icon
dirInfo = New DirectoryInfo(path_to_some_folder
'We use this For...Each to iterate over the collection of files in the folder
For Each fileInfo In dirInfo.GetFiles
'We can only find associated exes by extension, so don't show any files that have no extension
If fileInfo.Extension = String.Empty Then
Else
'Use the function to get the path to the executable for the file
exePath = GetAssociatedProgram(fileInfo.Extension)
'Use ExtractAssociatedIcon to get an icon from the path
exeIcon = Drawing.Icon.ExtractAssociatedIcon(exePath)
'Add the icon if we haven't got it already, with the executable path as the key
If ImageList1.Images.ContainsKey(exePath) Then
Else
ImageList1.Images.Add(exePath, exeIcon)
End If
'Add the file to the ListView, with the executable path as the key to the ImageList's image
ListView1.Items.Add(fileInfo.Name, exePath)
End If
Next
End Sub
GetAssociatedProgram comes from developer.com
Public Function GetAssociatedProgram(ByVal FileExtension As _
String) As String
' Returns the application associated with the specified
' FileExtension
' ie, path\denenv.exe for "VB" files
Dim objExtReg As Microsoft.Win32.RegistryKey = _
Microsoft.Win32.Registry.ClassesRoot
Dim objAppReg As Microsoft.Win32.RegistryKey = _
Microsoft.Win32.Registry.ClassesRoot
Dim strExtValue As String
Try
' Add trailing period if doesn't exist
If FileExtension.Substring(0, 1) <> "." Then _
FileExtension = "." & FileExtension
' Open registry areas containing launching app details
objExtReg = objExtReg.OpenSubKey(FileExtension.Trim)
strExtValue = objExtReg.GetValue("").ToString
objAppReg = objAppReg.OpenSubKey(strExtValue & _
"\shell\open\command")
' Parse out, tidy up and return result
Dim SplitArray() As String
SplitArray = Split(objAppReg.GetValue(Nothing).ToString, """")
If SplitArray(0).Trim.Length > 0 Then
Return SplitArray(0).Replace("%1", "")
Else
Return SplitArray(1).Replace("%1", "")
End If
Catch
Return ""
End Try
End Function
At the end of all of that, when you run this code on this folder:
alt text http://www.philippursglove.com/stackoverflow/listview1.png
you should get:
alt text http://www.philippursglove.com/stackoverflow/listview2.png

Answer 2

If you know the file name of the file whose icon you want, you can use the System.Drawing.Icon.ExtractAssociatedIcon function for that purpose. e.g.
Icon ico = System.Drawing.Icon.ExtractAssociatedIcon(#"C:\WINDOWS\system32\notepad.exe");
You can also refer to my answer to a related question for more implementation details.