Library tutorials & articles
File Extensions: Finding the default Icon
The Registry
And so to begin. First, we need to convert the filename into just a file extension. That is, remove everything before the “.”:
TempFileName = Right(FileName, Len(FileName) - InStrRev(FileName, ".") + 1)
Now we take a look at the registry and see if it has any record of this file type (it is, of course, possible that it doesn’t)
lngError = RegOpenKey(HKEY_CLASSES_ROOT, TempFileName, lngRegKeyHandle)
If lngError Then GoTo No_Icon 'we do not even have a valid extension so lets NOT try to find an
icon!
lngStringLength = 260
'Make space for the incoming string
strProgramName = Space$(260)
'Get the key value:
lngError = RegQueryValueEx(lngRegKeyHandle, vbNullString, 0, 0, strProgramName, lngStringLength)
If lngError Then
'if
there's an error then BIG TROUBLE so lets use the normal "windows" icon
'the world may be about to end (or its just an error) but we'll clean up anyway
lngError = RegCloseKey(lngRegKeyHandle)
GoTo No_Icon
End If
'if this generates an error then we can't do anthing about it anyway
lngError = RegCloseKey(lngRegKeyHandle)
'Cut the name down to size
strProgramName = Left(strProgramName, lngStringLength - 1)
You will notice that even when I am not going to use it I still make “lngError” receive any errors. I have left this in because it’s useful for debugging.
You will notice that if any errors occur in this code I use the line “GoTo No_Icon”. This is because even if we can’t get a default icon for this file type, we will still want to display something, ie: the windows icon:
Ok, now we have the key name of our second registry key (stored in “strProgramName”) what we need to do now is to get the location for the default icon. The value that we want is held inside the sub-key “DefaultIcon”. So in a very similarly to the last piece of code, we need to get this value
'Use the value of the
last key in the name of the next one (strProgramName
)
lngError = RegOpenKey(HKEY_CLASSES_ROOT, strProgramName & "\DefaultIcon", lngRegKeyHandle)
'there is no icon for this extension so lets NOT try to load what doesn't exist!
If lngError Then GoTo No_Icon
'The rest is just the
same as before
lngStringLength = 260
strDefaultIcon = Space$(260)
lngError = RegQueryValueEx(lngRegKeyHandle, vbNullString, 0, 0, strDefaultIcon, lngStringLength)
If lngError Then
lngError = RegCloseKey(lngRegKeyHandle)
GoTo No_Icon
End If
lngError = RegCloseKey(lngRegKeyHandle)
strDefaultIcon = Trim$(Left(strDefaultIcon, lngStringLength - 1))
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the icon may be in an exe file or dll file.
this is a veryyyyyyyy long way, and there are ready softwares available for it.
but it is discovered by me, so posting
in folder options, create a dummy file extension
click advanced,
change the icon of that file extension to desired icon; from dll or exe file.
open google talk (sounds funny naa)
now create a file with that extension
using file transfer option, send that file to someone
it is not needed that actual transfer shd take place, u only need to initiate the transfer & then u can abort the transfer.
now go to
%userprofile%\Local Settings\Temp\Google Talk\File Extensions
the icon file is seen there as a png image
open it with mspaint or similar software & save it as 256 color bitmap
change its extension to .ico from .bmp
& u r done
Thanks a lot for the help and the good job you're doing
Yves
I AM AN UNDERGRADUATE STUDYING COMPUTER PRORAMMING. i WILL NEED MORE EXPLANATION ON THIS TOPIC.
tOCHUKWU.
Absolutely brilliant! Works a treat.
THANKS VERY MUCH!!!
Looks like my reply is too large to fit in one post so I've put it here.
Hope this helps
Lovely coding couling! Its helped me alot.
I'm not too hot with API work though and have had trouble incorporating your two lots of code. I'm ultimately trying to display the associated file icons from a directory of scanned files from a database on a Listview (like Explorer), using a 16x16 picture box. 32x32 is no problem (in theoy) but I'm unable to get my head round the 16x16 bit.
Any help VERY much appreciated.
Really Very Nice
In the properties of the picturebox, set "AutoRedraw" to "True"
If you want to draw to other objects, you can either
1.
2. If your object has a “Picture” or “Image” property then you could use:
Object.Picture = Picture1.Image
Or
Object.Image = Picture1.Image
Hope this helps
Hi, this is great code! I just have one question...
When form minimize or is hidden behind another one, the drawn icon just dissapear, how can I make it persistant?? how can I convert it to a Picture Object I could manipulate to assign it to any other control???
Sorry this took a while
Ok, Small Icons:
These will be a little more complex, you will need to use two more windows APIs:
ExtractIconEx (instead of ExtractIconEx)
DrawIconEx (instead of DrawIcon)
These functions do basically the same thing, but they are capable of much more. ExtractIconEx can extract any number of Icons into two arrays (although in the example below I’ve only used two long variables “lngSmall” and “lngLarge”). DrawIconEx will allow you to draw the small icon as a 16 X 16 image instead of 32 X 32. This is just a small example of how to use the two functions, hopefully you can see how to alter the origional code. You will need:
two picture boxes (to receve the images)
an icon (in the code Ive used the path "C:\1.ico")
A command button (the subroutine is "command1_CLick()")
So for some code:
Private Declare Function DestroyIcon Lib "user32.dll" (ByVal hIcon As Long) As Long
Private Declare Function DrawIconEx Lib "user32.dll" (ByVal hDC As Long, ByVal xLeft As Long, ByVal yTop As Long, ByVal hIcon As Long, ByVal cxWidth As Long, ByVal cyWidth As Long, ByVal istepIfAniCur As Long, ByVal hbrFlickerFreeDraw As Long, ByVal diFlags As Long) As Long
Private Const DINORMAL = &H3 'Draw both the image mask in image data
Private Const DIDEFAULTSIZE = &H8 'Draw the icon at 32 X 32
Private Sub Command1Click()
Dim Retval As Long, lngLarge As Long, lngSmall As Long, hbrush As Long
' \/firstIcon \/Number of icons
Retval = ExtractIconEx("C:\1.ico", 0, lngLarge, lngSmall, 1)
Retval = DrawIconEx(Picture1.hDC, 0, 0, lngLarge, 0, 0, 0, 0, DINORMAL Or DIDEFAULTSIZE)
'note: DIDEFAULTSIZE tells windows to ignore the two parameters after "lngLarge".
Retval = DrawIconEx(Picture2.hDC, 0, 0, lngSmall, 16, 16, 0, 0, DINORMAL)
'"16,16 tells windows to draw the Icon 16 X 16 pixals
' left top Icon width height for drawing animated cursors brush type Flags
'Retval = DrawIconEx(Picture2.hDC, 0, 0, lngSmall, 16, 16, 0, 0, DINORMAL)
Retval = DestroyIcon(lngLarge) 'As in the article
Retval = DestroyIcon(lngSmall)
End Sub
To get ExatractIconEx to retrieve more than one Icon, replace lngLarge and lngSmall with arrays and set the last parameter “nIcons” to the number of icons to extract.
If this isn't clear just say so.
Fantastic tutorial. Especially as I've just started a project, this evening, that'll have file lists and icons - solved quite a head scratcher for me.
But I was wandering, is it a simple matter to use the small versions of the icons, as you get in explorer? If so, could someone tell me where to look for how
Tom.
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