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Get Icon Images Of Files, Folders, Drives, or Registered Files

Posted 07 August 2016 - 05:09 PM

Here is a way to get 32x32 or 16x16 icon images of any files, folders, or Drives by supplying the full path to the file, folder, or drive. Not only can you get the icon images directly from a file, folder, or drive but, you can also get icon images of any registered file type by supplying just a file extension.

This is handy for things like filling the ImageLists that are used for TreeViews or ListViews when building your own file/folder browsers or explorer type windows. However, it can be used for any purpose where you need the icon image for a file or folder. For example, a Button or PictureBox Image.

The only downfall to this method is that you are limited to only the 32x32 or 16x16 sizes for the images. Getting the larger images such as 48x48, 64x64, 128x128, and 256x256 sizes requires a bit more complex method. Perhaps i will post a snippet of how to do that at a later date. For now i will just show this simpler example.

I have put together the small Iconhelper class below which you can add to your project and call the GetIconImage function to get the icon image. The SHGetFileInfo Win32 Api function is used to do the work of getting the icon. However, since Icons are not so nice to work with in VB.Net and can appear blurry/distorted in the ListView or TreeView controls, i convert the Icon to a Bitmap image which makes the image clearer/cleaner looking and can be used easily with the Image property of any control.

So, enough rambling on. Add the Iconhelper class below to your project.
Imports System.Runtime.InteropServices

Public Enum IconSizes As Integer
    Large32x32 = 0
    Small16x16 = 1
End Enum

Public Class Iconhelper
    Private Const SHGFI_ICON As Integer = &H100
    Private Const SHGFI_USEFILEATTRIBUTES As Integer = &H10

    <StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
    Private Structure SHFILEINFOW
        Public hIcon As IntPtr
        Public iIcon As Integer
        Public dwAttributes As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=260)> Public szDisplayName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=80)> Public szTypeName As String
    End Structure

    <DllImport("shell32.dll", EntryPoint:="SHGetFileInfoW")>
    Private Shared Function SHGetFileInfoW(<MarshalAs(UnmanagedType.LPTStr)> ByVal pszPath As String, ByVal dwFileAttributes As Integer, ByRef psfi As SHFILEINFOW, ByVal cbFileInfo As Integer, ByVal uFlags As Integer) As Integer
    End Function

    <DllImport("user32.dll", EntryPoint:="DestroyIcon")> Private Shared Function DestroyIcon(ByVal hIcon As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

    ''' <summary>Gets a Bitmap image of the specified file or folder icon.</summary>
    ''' <param name="FileOrFolderPath">The full path to the folder or file to get the icon image from, or just a file extension (.ext) to get the registered icon image of the file type.</param>
    ''' <param name="IconSize">The size of the icon to retrieve.</param>
    Public Shared Function GetIconImage(ByVal FileOrFolderPath As String, ByVal IconSize As IconSizes) As Bitmap
        Dim bm As Bitmap = Nothing
        Dim fi As New SHFILEINFOW
        Dim flags As Integer = If(FileOrFolderPath.StartsWith("."), (IconSize Or SHGFI_USEFILEATTRIBUTES), IconSize)
        If SHGetFileInfoW(FileOrFolderPath, 0, fi, Marshal.SizeOf(fi), SHGFI_ICON Or flags) <> 0 Then
            bm = Icon.FromHandle(fi.hIcon).ToBitmap
        End If
        Return bm
    End Function
End Class

Now i will give you a few examples of how you can use the Iconhelper class to get both sizes of the icon image from a Folder, a HardDrive, and a File.

First add 2 PictureBoxes to the form and set their SizeMode property to CenterImage. You can then use any of the next few code examples below in the Form Load event or a Button Click event if you want for testing.
        'get the icon image for the Pictures folder
        Dim PictureFolderPath As String = Environment.GetFolderPath(Environment.SpecialFolder.MyPictures)
        PictureBox1.Image = Iconhelper.GetIconImage(PictureFolderPath, IconSizes.Large32x32)
        PictureBox2.Image = Iconhelper.GetIconImage(PictureFolderPath, IconSizes.Small16x16)

        'gets the icon images for the hard drive
        PictureBox1.Image = Iconhelper.GetIconImage("C:\", IconSizes.Large32x32)
        PictureBox2.Image = Iconhelper.GetIconImage("C:\", IconSizes.Small16x16)

        'gets the icon images from a Rich Text file
        PictureBox1.Image = Iconhelper.GetIconImage("C:\TestFolder\MyRtfFile.rtf", IconSizes.Large32x32)
        PictureBox2.Image = Iconhelper.GetIconImage("C:\TestFolder\MyRtfFile.rtf", IconSizes.Small16x16)

It should be pretty easy to see how it is used but, i will show an example of getting the icon image of a registered file extension type. It is done the same way but, you just supply the extension instead of a file or folder path. The extension must begin with the . character.
        'get the icon image for a .zip type file
        PictureBox1.Image = Iconhelper.GetIconImage(".zip", IconSizes.Large32x32)
        'get the icon image for a .vbproj type file.
        PictureBox2.Image = Iconhelper.GetIconImage(".vbproj", IconSizes.Large32x32)

Here i added several PictureBoxes to a form to show the Pictures Folder, the Hard Drive, and a Rich Text file icon.
Attached Image

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