How to display multiple messages in one MsgBox()? [VB.NET]

Question

I would like to scan my xml file whether the specific node is exists or not. Then, I wanted to show the number of files in a message box. For example, when I browse multiply files, then the output will show difference results in the MsgBox()

This is what I have tried:

 Private Sub WritingFile(ByVal strContent As String)
 Dim xmlDoc As New XmlDocument()
        xmlDoc.Load(strContent)

        Dim nodes As XmlNode

        Try
            nodes = xmlDoc.DocumentElement.SelectSingleNode("\PRODUCT\NAME")
                If nodes Is Nothing Then
                MsgBox("File Not Exist")<----<--- should display the no. of files not exists
            Else
                MsgBox("File Exists") <--- should display the no. of files exists
            End If

        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
End Sub

How can I display the results without the messagesbox display one by one for each files? Thank you

Answer 1

This is an example of how you could loop through the list of xml files

Private fileWithNode As Integer
Private fileWithoutNode As Integer

Private Sub CountValidFiles()

    Dim xmlFilePath As String = "c:\temp\myxmlfiles\"
    fileWithNode = 0
    fileWithoutNode = 0

    For Each filePath As String In Directory.GetFiles(xmlFilePath)
        ValidateFile(filePath)
    Next

    MessageBox.Show(String.Concat(String.Format("Files without node: {0}", fileWithoutNode),
                                  Environment.NewLine,
                                  String.Format("Files with node: {0}", fileWithNode)))

End Sub

Private Sub ValidateFile(strContent As String)
    Dim xmlDoc As New XmlDocument()
    xmlDoc.Load(strContent)

    Dim nodes As XmlNode

    Try
        nodes = xmlDoc.DocumentElement.SelectSingleNode("\PRODUCT\NAME")
        If nodes Is Nothing Then
            fileWithoutNode += 1 ' the no. Of files Not exists
        Else
            fileWithNode += 1 ' the no. Of files exists
        End If

    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub