'' Attempts to open the given file, and returns a boolean indicating success or failure
'' Never throws.
Function OpenFile(ByVal filePath As String)
    Try
        DTE.ItemOperations.OpenFile(filePath)
        Return True
    Catch ex As Exception
        Return False
    End Try
End Function

'' Opens the corresponding header/source file
'' Current file | Target file(s)
'' X.hpp        | X.cpp
'' X.h          | X.c, else X.cpp
'' X.cpp        | X.hpp, else X.h
'' X.c          | X.h
Public Sub SwitchHeaderToOrFromSource()
    If DTE.ActiveDocument Is Nothing Then Exit Sub

    Dim fileInfo As FileInfo = New FileInfo(DTE.ActiveDocument.FullName)

    Dim extensionMap As New Dictionary(Of String, String())
    extensionMap.Add(".hpp", New String() {".cpp"})
    extensionMap.Add(".h", New String() {".c", ".cpp"})
    extensionMap.Add(".cpp", New String() {".hpp", ".h"})
    extensionMap.Add(".c", New String() {".h"})

    Dim currentExt As String = LCase(fileInfo.Extension)
    If extensionMap.ContainsKey(currentExt) = False Then Exit Sub

    Dim extensions As String() = extensionMap(currentExt)
    Dim baseName = Path.GetFileNameWithoutExtension(fileInfo.FullName)
    For Each ext As String In extensions
        'MsgBox("Trying: " + baseName + ext)
        If OpenFile(baseName + ext) = True Then Exit Sub
    Next

    MsgBox("Could not find any corresponding h/c/hpp/cpp files to open")
End Sub

    '' Attempts to open the given file, and returns a boolean indicating success or failure
    '' Never throws.
    Function OpenFile(ByVal filePath As String)
        Try
            DTE.ItemOperations.OpenFile(filePath)
            Return True
        Catch ex As Exception
            Return False
        End Try
    End Function

    '' Opens the corresponding header/source file
    '' Current file | Target file(s)
    '' X.hpp        | X.cpp
    '' X.h          | X.c, else X.cpp
    '' X.cpp        | X.hpp, else X.h
    '' X.c          | X.h
    Public Sub nss_ToggleDesignAndCode_macro()
        If DTE.ActiveDocument Is Nothing Then Exit Sub

        Dim fileInfo As FileInfo = New FileInfo(DTE.ActiveDocument.FullName)

        Dim extensionMap As New Dictionary(Of String, String())
        extensionMap.Add(".hpp", New String() {".cpp"})
        extensionMap.Add(".h", New String() {".c", ".cpp"})
        extensionMap.Add(".cpp", New String() {".hpp", ".h"})
        extensionMap.Add(".c", New String() {".h"})
        extensionMap.Add(".master", New String() {".master.cs"})
        extensionMap.Add(".cs", New String() {""})
        extensionMap.Add(".aspx", New String() {".aspx.cs"})
        extensionMap.Add(".ascx", New String() {".ascx.cs"})

        Dim currentExt As String = LCase(fileInfo.Extension)
        If extensionMap.ContainsKey(currentExt) = False Then Exit Sub

        Dim extensions As String() = extensionMap(currentExt)
        Dim baseName = Path.GetFileNameWithoutExtension(fileInfo.FullName)
        For Each ext As String In extensions
            If OpenFile(fileInfo.DirectoryName + "\" + baseName + ext) = True Then Exit Sub
        Next

        MsgBox("Could not find any corresponding file to open")
    End Sub

Imports System
Imports System.Collections.Generic

'' Attempts to open the given file, and returns a boolean indicating success or failure
    '' Never throws.
    Function OpenFile(ByVal filePath As String)
        Try
            DTE.ItemOperations.OpenFile(filePath)
            Return True
        Catch ex As Exception
            Return False
        End Try
    End Function

    '' Opens the corresponding header/source file
    '' Current file | Target file(s)
    '' X.hpp        | X.cpp
    '' X.h          | X.c, else X.cpp
    '' X.cpp        | X.hpp, else X.h
    '' X.c          | X.h
    Public Sub SwitchHeaderToOrFromSource()
        If DTE.ActiveDocument Is Nothing Then Exit Sub

        Dim fileInfo As IO.FileInfo = New IO.FileInfo(DTE.ActiveDocument.FullName)

        Dim extensionMap As New Dictionary(Of String, String())
        extensionMap.Add(".hpp", New String() {".cpp"})
        extensionMap.Add(".h", New String() {".c", ".cpp"})
        extensionMap.Add(".cpp", New String() {".hpp", ".h"})
        extensionMap.Add(".c", New String() {".h"})

        Dim currentExt As String = LCase(fileInfo.Extension)
        If extensionMap.ContainsKey(currentExt) = False Then Exit Sub

        Dim extensions As String() = extensionMap(currentExt)
        Dim baseName = IO.Path.GetFileNameWithoutExtension(fileInfo.FullName)
        Dim path = fileInfo.DirectoryName

        For Each ext As String In extensions
            'MsgBox("Trying: " + baseName + ext)
            If OpenFile(path + "\" + baseName + ext) = True Then Exit Sub
        Next

        MsgBox("Could not find any corresponding h/c/hpp/cpp files to open")
    End Sub