Opening files with your program

[Flip]

If i made a text editor, for example, how would i make it so the user can click on my special .abc files and they would open up with MY editor? Possible in VB?

[AttnSue]

Are your .abc files text files?

[Oafo]

You'd have to create a registry key under HKEY_CLASSES_ROOT called ".abc" and then make a new folder called "ShellEx" and do something there, I've forgotten, sorry. Try searching, it could be somewhere.

[Flip]

AttnSue- its just an example, but yes (if you want, they can be txt files, i just want to know how to open them it my program)

Oafo- Thanks , thats a big help. Ill ask around about that.

Anyone else know how?

[James Stanich]

File Association 101:

'Make a new project. Add a module. To the form add a command button. 
 
'Code:
'Add this code to the module:
 
Option Explicit
 
Public Const REG_SZ As Long = 1
Public Const REG_DWORD As Long = 4
Public Const HKEY_CLASSES_ROOT = &H80000000
Public Const HKEY_CURRENT_USER = &H80000001
Public Const HKEY_LOCAL_MACHINE = &H80000002
Public Const HKEY_USERS = &H80000003
 
Public Const ERROR_NONE = 0
Public Const ERROR_BADDB = 1
Public Const ERROR_BADKEY = 2
Public Const ERROR_CANTOPEN = 3
Public Const ERROR_CANTREAD = 4
Public Const ERROR_CANTWRITE = 5
Public Const ERROR_OUTOFMEMORY = 6
Public Const ERROR_INVALID_PARAMETER = 7
Public Const ERROR_ACCESS_DENIED = 8
Public Const ERROR_INVALID_PARAMETERS = 87
Public Const ERROR_NO_MORE_ITEMS = 259
 
Public Const KEY_ALL_ACCESS = &H3F
Public Const REG_OPTION_NON_VOLATILE = 0
 
Public Declare Function RegCloseKey Lib "advapi32.dll" _
   (ByVal hKey As Long) As Long
 
Public Declare Function RegCreateKeyEx _
    Lib "advapi32.dll" Alias "RegCreateKeyExA" _
   (ByVal hKey As Long, _
    ByVal lpSubKey As String, _
    ByVal Reserved As Long, _
    ByVal lpClass As String, _
    ByVal dwOptions As Long, _
    ByVal samDesired As Long, _
    ByVal lpSecurityAttributes As Long, _
    phkResult As Long, _
    lpdwDisposition As Long) As Long
 
Public Declare Function RegOpenKeyEx _
    Lib "advapi32.dll" Alias "RegOpenKeyExA" _
   (ByVal hKey As Long, _
    ByVal lpSubKey As String, _
    ByVal ulOptions As Long, _
    ByVal samDesired As Long, _
    phkResult As Long) As Long
 
Public Declare Function RegSetValueExString _
    Lib "advapi32.dll" Alias "RegSetValueExA" _
   (ByVal hKey As Long, _
    ByVal lpValueName As String, _
    ByVal Reserved As Long, _
    ByVal dwType As Long, _
    ByVal lpValue As String, _
    ByVal cbData As Long) As Long
 
Public Declare Function RegSetValueExLong _
   Lib "advapi32.dll" Alias "RegSetValueExA" _
  (ByVal hKey As Long, _
   ByVal lpValueName As String, _
   ByVal Reserved As Long, _
   ByVal dwType As Long, _
   lpValue As Long, _
   ByVal cbData As Long) As Long
 
 
Public Sub CreateAssociation()
 
   Dim sPath As String
   
  'File Associations begin with a listing
  'of the default extension under HKEY_CLASSES_ROOT.
  'So the first step is to create that
  'root extension item
   CreateNewKey ".xxx", HKEY_CLASSES_ROOT
   
   
  'To the extension just added, add a
  'subitem where the registry will look for
  'commands relating to the .xxx extension
  '("MyApp.Document"). Its type is String (REG_SZ)
   SetKeyValue ".xxx", "", "MyApp.Document", REG_SZ
   
   
  'Create the 'MyApp.Document' item under
  'HKEY_CLASSES_ROOT. This is where you'll put
  'the command line to execute or other shell
  'statements necessary.
   CreateNewKey "MyApp.Document\shell\open\command", HKEY_CLASSES_ROOT
   
   
  'Set its default item to "MyApp Document".
  'This is what is displayed in Explorer against
  'for files with a xxx extension. Its type is
  'String (REG_SZ)
   SetKeyValue "MyApp.Document", "", "MyApp Document", REG_SZ
   
   
  'Finally, add the path to myapp.exe
  'Remember to add %1 as the final command
  'parameter to assure the app opens the passed
  'command line item.
  '(results in '"c:\LongPathname\Myapp.exe %1")
  'Again, its type is string.
   sPath = "c:\LongPathname\Myapp.exe %1"
   SetKeyValue "MyApp.Document\shell\open\command", "", sPath, REG_SZ
   
  'All done
   MsgBox "The file association has been made!"
   
End Sub
 
 
Public Function SetValueEx(ByVal hKey As Long, _
                           sValueName As String, _
                           lType As Long, _
                           vValue As Variant) As Long
 
   Dim nValue As Long
   Dim sValue As String
   
   Select Case lType
      Case REG_SZ
         sValue = vValue & Chr$(0)
         SetValueEx = RegSetValueExString(hKey, _
                                          sValueName, _
                                          0&, _
                                          lType, _
                                          sValue, _
                                          Len(sValue))
         
      Case REG_DWORD
         nValue = vValue
         SetValueEx = RegSetValueExLong(hKey, _
                                        sValueName, _
                                        0&, _
                                        lType, _
                                        nValue, _
                                        4)
   
   End Select
   
End Function
 
 
Public Sub CreateNewKey(sNewKeyName As String, _
                        lPredefinedKey As Long)
 
  'handle to the new key
   Dim hKey As Long
  
  'result of the RegCreateKeyEx function
   Dim r As Long
   
   r = RegCreateKeyEx(lPredefinedKey, _
                      sNewKeyName, 0&, _
                      vbNullString, _
                      REG_OPTION_NON_VOLATILE, _
                      KEY_ALL_ACCESS, 0&, hKey, r)
   
   Call RegCloseKey(hKey)
 
End Sub
 
 
Public Sub SetKeyValue(sKeyName As String, _
                       sValueName As String, _
                       vValueSetting As Variant, _
                       lValueType As Long)
 
  'result of the SetValueEx function
   Dim r As Long
   
  'handle of opened key
   Dim hKey As Long
   
  'open the specified key
   r = RegOpenKeyEx(HKEY_CLASSES_ROOT, _
                    sKeyName, 0, _
                    KEY_ALL_ACCESS, hKey)
                    
   r = SetValueEx(hKey, _
                  sValueName, _
                  lValueType, _
                  vValueSetting)
                  
   Call RegCloseKey(hKey)
 
End Sub
 
'Add this code to the command button:
 
Private Sub Command1_Click()
CreateAssociation
End Sub

To get list of associations on your system :

''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Copyright ©1996-2001 VBnet, Randy Birch, All Rights Reserved.
' Some pages may also contain other copyrights by the author.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' You are free to use this code within your own applications,
' but you are expressly forbidden from selling or otherwise
' distributing this source code without prior written consent.
' This includes both posting free demo projects made from this
' code as well as reproducing the code in text or html format.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
Private Const MAX_PATH As Long = 260
Private Const HKEY_CLASSES_ROOT As Long = &H80000000
Private Const ERROR_SUCCESS As Long = 0
Private Const vbDot As Long = 46 
Private Const SHGFI_USEFILEATTRIBUTES As Long = &H10
Private Const SHGFI_TYPENAME As Long = &H400
Private Const LB_SETTABSTOPS As Long = &H192
 
Private Type FILETIME 
   dwLowDateTime As Long
   dwHighDateTime As Long
End Type
 
Private Type SHFILEINFO
   hIcon As Long
   iIcon As Long
   dwAttributes As Long
   szDisplayName As String * MAX_PATH
   szTypeName As String * 80
End Type
 
Private Declare Function RegEnumKeyEx Lib "advapi32.dll" Alias "RegEnumKeyExA" (ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpName As String, lpcbName As Long, ByVal lpReserved As Long, ByVal lpClass As String, lpcbClass As Long, lpftLastWriteTime As FILETIME) As Long
Private Declare Function SHGetFileInfo Lib "shell32" Alias "SHGetFileInfoA" (ByVal pszPath As String, ByVal dwFileAttributes As Long, psfi As SHFILEINFO, ByVal cbFileInfo As Long, ByVal uFlags As Long) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
 
Private Sub GetAssociatedFileListing()
 
   Dim dwIndex As Long
   Dim sTypeName As String
   Dim sSubkey As String * MAX_PATH
   Dim sClass As String * MAX_PATH
   Dim ft As FILETIME
   
   Do While RegEnumKeyEx(HKEY_CLASSES_ROOT, _
                         dwIndex, _
                         sSubkey, _
                         MAX_PATH, _
                         0, sClass, _
                         MAX_PATH, ft) = ERROR_SUCCESS
      
      If Asc(sSubkey) = vbDot Then
         
        'Pass the returned string to get the file type
         sTypeName = GetFileType(sSubkey)
            
         If Len(sTypeName) > 0 Then
            List1.AddItem TrimNull(sSubkey) & vbTab & sTypeName
         End If            
      End If
      dwIndex = dwIndex + 1   
   Loop
End Sub
 
Private Function GetFileType(sFile As String) As String
 
  'If successful returns the specified file's
  'typename, returns an empty string otherwise.
  'sFile does not have to exist and can be
  'just a file extension.
   Dim sfi As SHFILEINFO
 
   If SHGetFileInfo(sFile, 0&, _
                    sfi, Len(sfi), _
                    SHGFI_TYPENAME Or SHGFI_USEFILEATTRIBUTES) Then
      GetFileType = TrimNull(sfi.szTypeName)
   End If
 
End Function
 
Private Function TrimNull(startstr As String) As String
 
  'returns the string up to the first
  'null, if present, or the passed string
   Dim pos As Integer
   
   pos = InStr(startstr, Chr$(0))
   
   If pos Then
      TrimNull = Left$(startstr, pos - 1)
      Exit Function
   End If
  
   TrimNull = startstr
  
End Function
 
Private Sub Command1_Click()
   List1.Clear
   Screen.MousePointer = vbHourglass   
  'fill the listbox box with the file types and their extensions
   Call GetAssociatedFileListing   
   Screen.MousePointer = vbDefault   
 
End Sub

[Flip]

Thanks James! Some day ill be smart like you...

[James Stanich]

Not smart I just know where to look (and how to store snippets of code)...

Glad I could help...