Report error/warning if missing files in project/solution in Visual Studio

Question

Is there a way for Visual Studio to report an error/warning when you build a solution that has missing files (yellow triangle icon with exclamation) that do have necessarily

Answer 1

When we had missing files, we were getting crazy compile errors, like unable to write xyz.pdb even though the file ended up getting written. I took what Simon had provided (thanks!) and flipped it around a bit; specifically, I added a bit of recursion and added support for folders and files with sub-files (e.g. datasets, code-behinds).

Private Sub BuildEvents_OnBuildBegin(ByVal Scope As EnvDTE.vsBuildScope, ByVal Action As EnvDTE.vsBuildAction) Handles BuildEvents.OnBuildBegin

    For Each proj As Project In DTE.Solution.Projects
        walkTree(proj.ProjectItems, False)
    Next

End Sub

Private Sub walkTree(ByVal list As ProjectItems, ByVal showAll As Boolean)

    For Each item As ProjectItem In list

        ' from http://msdn.microsoft.com/en-us/library/z4bcch80(v=vs.80).aspx
        ' physical files:   {6BB5F8EE-4483-11D3-8BCF-00C04F8EC28C}
        ' physical folders: {6BB5F8EF-4483-11D3-8BCF-00C04F8EC28C}

        If (item.Kind = "{6BB5F8EE-4483-11D3-8BCF-00C04F8EC28C}" OrElse _
            item.Kind = "{6BB5F8EF-4483-11D3-8BCF-00C04F8EC28C}") Then

            For i As Integer = 1 To item.FileCount ' appears to be 1 all the time...

                Dim existsOrIsFolder As Boolean = (item.Kind = "{6BB5F8EF-4483-11D3-8BCF-00C04F8EC28C}" OrElse System.IO.File.Exists(item.FileNames(i)))

                If (showAll OrElse _
                    existsOrIsFolder = False) Then

                    WriteToBuildWindow(String.Format("{0}, {1}, {2} ", existsOrIsFolder, item.ContainingProject.Name, item.FileNames(i)))

                End If

            Next

            If (item.ProjectItems.Count > 0) Then
                walkTree(item.ProjectItems, showAll)
            End If

        End If

    Next

End Sub

Private Sub WriteToBuildWindow(ByVal text As String)
    Dim ow As OutputWindow = DTE.Windows.Item(EnvDTE.Constants.vsWindowKindOutput).Object
    Dim build As OutputWindowPane = ow.OutputWindowPanes.Item("Build")
    build.OutputString(text & Environment.NewLine)
End Sub