Set Registry key to make program a default

[Robert Homes]

How to set registry key to make program a default for a particular file type. My program works with .JPG files. I'd like to set the registry to treat my program as the default for such files.

 

[jmcilhinney]

Do you have an installer for your app? That's the simplest option.

 

[Robert Homes]

Not yet., But I expect to have one soon. Actually, I'm still developing the program and its not quite finished. I'm must working on this to get ready for when I'm done. I have someone helping me with the installer aspect. I didn't realize that the installer could probably set the default I'm looking for. Thanks for that insight.

 

[jdelano]

A second option is on the first app launch, you can ask the user if they want this app to be the default for JPG files. If yes, then you can write to the registry Reading from and Writing to the Registry Using the Microsoft.Win32 Namespace - Visual Basic

This post has some info on where the application defaults are stored in the registry Where in the registry does Windows store with which program to open certain file types?

 

[JohnH]

It is also possible to open Default Apps settings where user can choose:

Process.Start(New ProcessStartInfo("ms-settings:defaultapps") With {.UseShellExecute = True})

 

[Rythorian]

This is another way, but JohnH gave you the fastest approach.

Imports Microsoft.Win32

Module Module1
   Private Sub Main()
        Dim appName As String = "YourAppName"
        Dim appPath As String = "C:\Path\To\YourApp.exe"

        ' Set the default application for .jpg files
        SetDefaultApp(".jpg", appName, appPath)
        ' Set the default application for .png files
        SetDefaultApp(".png", appName, appPath)
        ' Set the default application for .bmp files
        SetDefaultApp(".bmp", appName, appPath)
    End Sub

   Private Sub SetDefaultApp(extension As String, appName As String, appPath As String)
        Dim key As RegistryKey = Registry.ClassesRoot.CreateSubKey(extension)
        key.SetValue("", appName)

        Dim appKey As RegistryKey = Registry.ClassesRoot.CreateSubKey(appName)
        appKey.SetValue("", "Image File")
        appKey.CreateSubKey("shell\open\command").SetValue("", """" & appPath & """ ""%1""")
    End Sub
End Module