Validating login credentials against XML

Daniel Chong

16y5.5k

Hi i need help with a simple program that i am doing in VB.NET involving the use of XML.
let us assume that i have created a simple form with a two textboxes for entering Username and Password, and a Login button.

I have this simple XML file that stores the different username and passwords.

xml version="1.0" encoding="utf-8" ?>
<AuthenticationList>
<User id="01">
<Username>cs_helper01Username>
<Password>cshelper01Password>
User>
<User id="02">
<Username>cs_helper02Username>
<Password>cshelper02Password>
User>
<User id="03">
<Username>cs_helper03Username>
<Password>cshelper03Password>
User>
<User id="04">
<Username>cs_managerUsername>
<Password>csmanagerPassword>
User>
AuthenticationList>

when the login button is clicked, it needs to check the xml file storing the user and password. it needs to do validation of the textbox entries. but i do not know how to do this step. any help would be welcome!

2 Replies

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mihir soni16y ago
And here is another way to do this
http://www.vbdotnetheaven.com/UploadFile/bulentozkir/XMLfileUsingXmlDocument04232005010454AM/XMLfileUsingXmlDocument.aspx

may be it ll also help you

mihir soni16y ago

Hello Daniel,

Here u have done one example in that i have taken one textbox and one buttopn and i have put this code in button click event

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim doc As XPathDocument
        Dim nav As XPathNavigator
        Dim iter As XPathNodeIterator
        doc = New XPathDocument("XMLFile1.xml")
        nav = doc.CreateNavigator
        iter = nav.Select("AuthenticationList") 'Your node name goes here
        'Loop through the records in that node
        While iter.MoveNext
            'Get the data we need from the node
            Dim iterNews As XPathNodeIterator
            Dim lstNav As XPathNavigator
            '''''''''''''''''''''''''''''''''''''''''''''''''' ''
            lstNav = iter.Current
            iterNews = lstNav.SelectDescendants(XPathNodeType.Element, False)
            'Loop through the child nodes
            While iterNews.MoveNext
                If (TextBox1.Text = iterNews.Current.Value) Then
                    MsgBox("Sucess")
                    Exit While
                End If
            End While
        End While
    End Sub

It will search all the nodes and if this match than it it ll get out of loop
 Dim DS As New DataSet()
' don't forget to change the path
DS.ReadXml("yourxmlpath")

Dim I As Integer

' change names to caps
For I = 0 To DS.Tables(0).Rows.Count - 1
  DS.Tables(0).Rows(I).Item("Name") = _
     UCase(DS.Tables(0).Rows(I).Item("Name"))
Next
' Display the result
For I = 0 To DS.Tables(0).Rows.Count - 1
if(textbox1.text=DS.Tables(0).Rows(I).item("username")) then
      'Do some code here
else
      'Error messege
End if

Next