Question

I am trying to use xml documents to store data for a movie database, but am having an issue, I am new to using xml for documents and have been using tutorials and MSDN to figure it out but I am stuck thanks in advance

here is the code I am using

Imports <"...\movies.xml">

Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click

    Dim movieToAdd As Movie = getMovieInfo()
    MovieBindingSource.AddNew()
    Dim doc = XDocument.Load("..\..\movies.xml")
    Dim movieAdd = (<temp>
                        <Movie>
                            <MovieID><%= movieToAdd.MovieID %></MovieID>
                            <MovieTitle><%= movieToAdd.MovieTitle %></MovieTitle>
                            <Studio><%= movieToAdd.Studio %></Studio>
                            <Director><%= movieToAdd.Direcotor %></Director>
                            <ReleaseYear><%= movieToAdd.ReleaseYear %></ReleaseYear>
                            <Genre><%= movieToAdd.Genre %></Genre>
                            <Rating><%= movieToAdd.Rating %></Rating>
                            <DVD><%= movieToAdd.DVD %></DVD>
                            <BluRay><%= movieToAdd.BluRay %></BluRay>
                            <VHS><%= movieToAdd.VHS %></VHS>
                            <ScreenFormat><%= movieToAdd.ScreenFormat %></ScreenFormat>
                            <MovieCase><%= movieToAdd.MovieCase %></MovieCase>
                            <RunTime><%= movieToAdd.RunTime %></RunTime>
                            <NumberOfDiscs><%= movieToAdd.NumberOfDiscs %></NumberOfDiscs>
                        </Movie>
                    </temp>)
    Try
        Dim addMovie = doc.<movies:Movies>(0)
        addMovie.Add(movieAdd.Nodes())
        doc.Save("..\..\movies.xml")
    Catch ex As Exception
        Throw ex
    End Try
End Sub

Private Function getMovieInfo() As Movie

    Dim movieToAdd As New Movie

    movieToAdd.MovieID = CInt(MovieIDTextBox.Text)
    movieToAdd.MovieTitle = MovieTitleTextBox.Text
    movieToAdd.Studio = StudioTextBox.Text
    movieToAdd.Direcotor = DirecotorTextBox.Text
    movieToAdd.ReleaseYear = ReleaseYearTextBox.Text
    movieToAdd.Genre = GenreComboBox.SelectedText
    movieToAdd.Rating = RatingComboBox.SelectedText
    movieToAdd.ScreenFormat = ScreenFormatComboBox.SelectedText
    movieToAdd.NumberOfDiscs = NumberOfDiscsTextBox.Text
    movieToAdd.RunTime = CInt(RunTimeTextBox.Text)
    movieToAdd.BluRay = CBool(BluRayCheckBox.CheckState)
    movieToAdd.DVD = CBool(DVDCheckBox.CheckState)
    movieToAdd.VHS = CBool(VHSCheckBox.CheckState)
    movieToAdd.MovieCase = CBool(MovieCaseCheckBox.CheckState)

    Return movieToAdd
End Function

Inn xml file I get this

<Movie xmlns="">
  <MovieID>22</MovieID>
  <MovieTitle>test</MovieTitle>
  <Studio>test</Studio>
  <Director>test</Director>
  <ReleaseYear>2121</ReleaseYear>
  <Genre></Genre>
  <Rating></Rating>
  <DVD>false</DVD>
  <BluRay>false</BluRay>
  <VHS>false</VHS>
  <ScreenFormat></ScreenFormat>
  <MovieCase>false</MovieCase>
  <RunTime>123</RunTime>
  <NumberOfDiscs>2</NumberOfDiscs>
</Movie>

Why do I get that xmlns = "" in the movie parent node?

Of I remove the parent node from the movieAdd variable it puts xlmns = in all the nodes

Can anyone show me what I am doing wrong?

Answer 1

It seems (although you didn’t share it) that the movies XML file uses namespaces. So I assume that somewhere in that file (probably on the root element) you will have something like xmlns=”mymovieurl”.
The important thing to realize is that each XML element and attribute is identified by a pair of strings. The local name (Movie, DVD, VHS, …) and the namespace URI (empty, mymovieurl, …). In your code above, since you didn’t specify a default namespace all your elements are in the empty namespace (their namespace URI is an empty string).
But your XML file to which you’re adding these have its elements in some non-empty namespace (mymovieurl).
In order to preserve the namespace for the element you’re adding the code has to inject the xmlns=”” attribute which marks that element and all its children to be in the empty namespace (just like you specified it in your code).

The solution depends on what you want to achieve. I assume that you want to add the elements into the namespace the rest of the file uses.

One simple way to do that is to add
Imports

That means that all elements in your code without a prefix should belong to the namespace “mymovieurl”. (Just change that to whatever namespace URI you movies file is using).