How To Associate a Custom Icon with a File Extension (247529)

MORE INFORMATION

Step-by-Step Example

1. Copy an icon into the application directory and name it myIcon.ico.
2. Start a new Visual Basic Standard EXE project. Form1 is created by default.
3. On the Project menu, select Project1 properties. Set the Project Name field to MyApp.
4. On the Project menu, choose Components. In the Components dialog box, select "Microsoft RichTextBox Control" and click OK.
5. Cite an instance of the RichTextBox control on Form1.
6. Add the following code to the General Declarations section of Form1:

   Option Explicit
   
   Private Declare Function RegCreateKey Lib "advapi32.dll" _
    Alias "RegCreateKeyA" (ByVal hKey As Long, _
                           ByVal lpSubKey As String, _
                           phkResult As Long) As Long
                    
   Private Declare Function RegSetValue Lib "advapi32.dll" _
    Alias "RegSetValueA" (ByVal hKey As Long, _
                          ByVal lpSubKey As String, _
                          ByVal dwType As Long, _
                          ByVal lpData As String, _
                          ByVal cbData As Long) As Long
   
   ' Return codes from Registration functions.
   Const ERROR_SUCCESS = 0&
   Const ERROR_BADDB = 1&
   Const ERROR_BADKEY = 2&
   Const ERROR_CANTOPEN = 3&
   Const ERROR_CANTREAD = 4&
   Const ERROR_CANTWRITE = 5&
   Const ERROR_OUTOFMEMORY = 6&
   Const ERROR_INVALID_PARAMETER = 7&
   Const ERROR_ACCESS_DENIED = 8&
   
   Private Const HKEY_CLASSES_ROOT = &H80000000
   Private Const MAX_PATH = 260&
   Private Const REG_SZ = 1
   
   Private Declare Sub SHChangeNotify Lib "shell32.dll" _
              (ByVal wEventId As Long, _
               ByVal uFlags As Long, _
               dwItem1 As Any, _
               dwItem2 As Any)
   
   Const SHCNE_ASSOCCHANGED = &H8000000
   Const SHCNF_IDLIST = &H0&
   
   Private Sub Form_Click()
      Dim sKeyName As String   ' Holds Key Name in registry.
      Dim sKeyValue As String  ' Holds Key Value in registry.
      Dim ret&           ' Holds error status if any from API calls.
      Dim lphKey&        ' Holds  key handle from RegCreateKey.
      Dim path As String
   
      path = App.path
      If Right(path, 1) <> "\" Then
         path = path & "\"
      End If
   
   ' This creates a Root entry called "MyApp".
      sKeyName = "MyApp"
      sKeyValue = "My Application"
      ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
      ret& = RegSetValue&(lphKey&, "", REG_SZ, sKeyValue, 0&)
   
   ' This creates a Root entry called .BAR associated with "MyApp".
      sKeyName = ".BAR"
      sKeyValue = "MyApp"
      ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
      ret& = RegSetValue&(lphKey&, "", REG_SZ, sKeyValue, 0&)
   
   ' This sets the command line for "MyApp".
      sKeyName = "MyApp"
      sKeyValue = path & "MyApp.exe %1"
      ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
      ret& = RegSetValue&(lphKey&, "shell\open\command", REG_SZ, _
                          sKeyValue, MAX_PATH)
   
   ' This sets the icon for the file extension
      sKeyName = "MyApp"
      sKeyValue = path & "myIcon.ico"
      ret& = RegCreateKey&(HKEY_CLASSES_ROOT, sKeyName, lphKey&)
      ret& = RegSetValue&(lphKey&, "DefaultIcon", REG_SZ, _
                          sKeyValue, MAX_PATH)
    
   ' This notifies the shell that the icon has changed
      SHChangeNotify SHCNE_ASSOCCHANGED, SHCNF_IDLIST, 0, 0
   
   End Sub
   
   Private Sub Form_Load()
    ' When the file is double clicked the name is stored in Command()
   
      RichTextBox1.LoadFile Command()
   End Sub
   					

7. From the File menu, choose Make Project1.exe and compile the project as MyApp.exe.
8. In the application directory, create a text file named myFile.bar and enter some text into it. The file displays the default Windows icon.
9. Now run MyApp.exe and click on the form. This creates the following structure in the Registry:

   .bar = MyApp
         MyApp = My Application
           | 
            -- DefaultIcon= myIcon.ico
           |
            -- Shell
                 |
                  ----open
                       |
                        ------command = MyApp.exe %1
   					

10. The icon of myFile.bar is changed to myIcon.ico.
11. Double-clicking myFile.bar starts MyApp.exe and the text is seen in the RichTextBox control.