Memory can not Read

[yxq]

Using the function below, i can get icon from a file to imagelist, but when
exit my program, system will pop up a error box of "Memory can not Read",
why? My system is Windows XP & sp2

*************************************************************************************
<Flags()> Private Enum SHGFI
SmallIcon = &H1
LargeIcon = &H0
Icon = &H100
DisplayName = &H200
Typename = &H400
SysIconIndex = &H4000
UseFileAttributes = &H10
End Enum

Public Enum IconSize
SmallIcon = 1
LargeIcon = 0
End Enum

<StructLayout(LayoutKind.Sequential)> _
Private Structure SHFILEINFO
Public hIcon As IntPtr
Public iIcon As Integer
Public dwAttributes As Integer
<MarshalAs(UnmanagedType.LPStr, SizeConst:=260)> Public
szDisplayName As String
<MarshalAs(UnmanagedType.LPStr, SizeConst:=80)> Public
szTypeName As String

Public Sub New(ByVal B As Boolean)
hIcon = IntPtr.Zero
iIcon = 0
dwAttributes = 0
szDisplayName = vbNullString
szTypeName = vbNullString
End Sub
End Structure

Private Declare Auto Function SHGetFileInfo Lib "shell32" (ByVal
pszPath As String, ByVal dwFileAttributes As Integer, ByRef psfi As
SHFILEINFO, ByVal cbFileInfo As Integer, ByVal uFlagsn As SHGFI) As Integer

'Get the icon
Public Shared Function GetDefaultIcon(ByVal Path As String, Optional
ByVal IconSize As IconSize = IconSize.SmallIcon, Optional ByVal SaveIconPath
As String = "") As Icon
Dim info As New SHFILEINFO(True)
Dim cbSizeInfo As Integer = Marshal.SizeOf(info)
Dim flags As SHGFI = SHGFI.Icon Or SHGFI.UseFileAttributes
flags = flags + IconSize
SHGetFileInfo(Path, 256, info, cbSizeInfo, flags)
GetDefaultIcon = Icon.FromHandle(info.hIcon)

If SaveIconPath <> "" Then
Dim FileStream As New IO.FileStream(SaveIconPath,
IO.FileMode.Create)
GetDefaultIcon.Save(FileStream)
FileStream.Close()
End If
End Function

 

[Ken Tucker [MVP]]

Hi,

Here is an example that adds the filenames with there icons to a
listview and imagelist.

Private Function getLocalIcons(ByVal szFolderPath As String)

Dim dirInfo As New System.IO.DirectoryInfo(szFolderPath)

Dim di As System.IO.DirectoryInfo

Dim fi As System.IO.FileInfo

Dim lvitem As ListViewItem

Dim hIcon As Icon

Dim cIcon As New clsGetIcon

Dim htIcons As New Hashtable

Dim intIndex As Integer

imlIcon.Images.Clear()

lv.Items.Clear()

lv.SmallImageList = imlIcon

For Each di In dirInfo.GetDirectories()

lvitem = lv.Items.Add(di.Name)

hIcon = cIcon.getIcon(di.FullName)

If htIcons.ContainsKey(hIcon) Then

intIndex = htIcons(hIcon)

Else

imlIcon.Images.Add(hIcon.ToBitmap)

intIndex = imlIcon.Images.Count - 1

End If

lvitem.ImageIndex = intIndex

Next

For Each fi In dirInfo.GetFiles()

lvitem = lv.Items.Add(fi.Name)

hIcon = cIcon.getIcon(fi.FullName)

If htIcons.ContainsKey(hIcon) Then

intIndex = htIcons(hIcon)

Else

imlIcon.Images.Add(hIcon.ToBitmap)

intIndex = imlIcon.Images.Count - 1

End If

lvitem.ImageIndex = intIndex

Next

End Function

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

lv.SuspendLayout()

getLocalIcons("C:\")

lv.ResumeLayout()

End Sub



The helper class.

Imports System.Runtime.InteropServices

Public Class clsGetIcon

Public Structure SHFILEINFO

Dim hIcon As IntPtr

Dim iIcon As Integer

Dim dwAttributes As Integer

<VBFixedString(260),
System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValTStr,
SizeConst:=260)> Public szDisplayName As String

'String that contains the name of the file as it appears in the Microsoft®
Windows® Shell, or the path and file name of the file that contains the icon
representing the file.

<VBFixedString(80),
System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValTStr,
SizeConst:=80)> Public szTypeName As String

End Structure


Private Declare Auto Function SHGetFileInfo Lib "shell32" (ByVal pszPath As
String, _

ByVal dwFileAttributes As Integer, ByRef psfi As SHFILEINFO, _

ByVal cbFileInfo As Integer, ByVal uFlags As Integer) As Integer

Private Const SHGFI_ICON As Integer = &H100

Private Const SHGFI_SMALLICON As Integer = &H1 'Small icon

Private Const SHGFI_TYPENAME As Integer = &H400 ' get type name



Public Function getIcon(ByVal szFilename As String) As Icon

Try

Dim aSHFileInfo As New SHFILEINFO

Dim cbFileInfo As Integer = _

Marshal.SizeOf(aSHFileInfo)

Dim uflags As Integer = SHGFI_ICON Or SHGFI_SMALLICON

SHGetFileInfo(szFilename, 0, aSHFileInfo, cbFileInfo, uflags)

Dim myIcon As Icon

myIcon = Icon.FromHandle(aSHFileInfo.hIcon)

aSHFileInfo.szTypeName = Space(255)

SHGetFileInfo(szFilename, 0, aSHFileInfo, cbFileInfo, SHGFI_TYPENAME)

Trace.WriteLine(aSHFileInfo.szTypeName)

Return myIcon

Catch ex As Exception

Debug.WriteLine(ex.ToString)

Return Nothing

End Try

End Function

End Class



Ken

---------------------------
Using the function below, i can get icon from a file to imagelist, but when
exit my program, system will pop up a error box of "Memory can not Read",
why? My system is Windows XP & sp2

*************************************************************************************
<Flags()> Private Enum SHGFI
SmallIcon = &H1
LargeIcon = &H0
Icon = &H100
DisplayName = &H200
Typename = &H400
SysIconIndex = &H4000
UseFileAttributes = &H10
End Enum

Public Enum IconSize
SmallIcon = 1
LargeIcon = 0
End Enum

<StructLayout(LayoutKind.Sequential)> _
Private Structure SHFILEINFO
Public hIcon As IntPtr
Public iIcon As Integer
Public dwAttributes As Integer
<MarshalAs(UnmanagedType.LPStr, SizeConst:=260)> Public
szDisplayName As String
<MarshalAs(UnmanagedType.LPStr, SizeConst:=80)> Public
szTypeName As String

Public Sub New(ByVal B As Boolean)
hIcon = IntPtr.Zero
iIcon = 0
dwAttributes = 0
szDisplayName = vbNullString
szTypeName = vbNullString
End Sub
End Structure

Private Declare Auto Function SHGetFileInfo Lib "shell32" (ByVal
pszPath As String, ByVal dwFileAttributes As Integer, ByRef psfi As
SHFILEINFO, ByVal cbFileInfo As Integer, ByVal uFlagsn As SHGFI) As Integer

'Get the icon
Public Shared Function GetDefaultIcon(ByVal Path As String, Optional
ByVal IconSize As IconSize = IconSize.SmallIcon, Optional ByVal SaveIconPath
As String = "") As Icon
Dim info As New SHFILEINFO(True)
Dim cbSizeInfo As Integer = Marshal.SizeOf(info)
Dim flags As SHGFI = SHGFI.Icon Or SHGFI.UseFileAttributes
flags = flags + IconSize
SHGetFileInfo(Path, 256, info, cbSizeInfo, flags)
GetDefaultIcon = Icon.FromHandle(info.hIcon)

If SaveIconPath <> "" Then
Dim FileStream As New IO.FileStream(SaveIconPath,
IO.FileMode.Create)
GetDefaultIcon.Save(FileStream)
FileStream.Close()
End If
End Function

 

[Herfried K. Wagner [MVP]]

<StructLayout(LayoutKind.Sequential)> _

Replace the line above with this one:

\\\

Private Structure SHFILEINFO
Public hIcon As IntPtr
Public iIcon As Integer
Public dwAttributes As Integer
<MarshalAs(UnmanagedType.LPStr, SizeConst:=260)> Public
szDisplayName As String
<MarshalAs(UnmanagedType.LPStr, SizeConst:=80)> Public
szTypeName As String

Replace the two lines above with these:

\\\
<MarshalAs(UnmanagedType.ByValTStr, SizeConst:=260)> _
Publiv szDisplayName As String
<MarshalAs(UnmanagedType.ByValTStr, SizeConst:=80)> _
Public szTypeName As String
///

 

[Armin Zingler]

Hi,

Here is an example that adds the filenames with there icons to
a
listview and imagelist.
[...]

Ken, if you paste your code to notepade first, then into your posting,
formatting remains and no additional lines are inserted. Better to read.


Armin