Windows Phone Delete data in Web Server

Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Json
Imports System.Collections.ObjectModel
Imports System.IO
Imports System.Text

Partial Public Class MainPage
    Inherits PhoneApplicationPage

    ' Constructor
    Public Sub New()
        InitializeComponent()

        AddHandler Loaded, AddressOf MainPage_Loaded
    End Sub

    Dim prog As ProgressIndicator

    Private Sub MainPage_Loaded(sender As Object, e As System.Windows.RoutedEventArgs)
        LoadData()
    End Sub

    Private Sub LoadData()
        Dim url As String = "http://localhost/myphp/showAllData.php"
        Dim uri As Uri = New Uri(url, UriKind.Absolute)

        Dim postData As StringBuilder = New StringBuilder()
        postData.AppendFormat("{0}={1}", "NULL", HttpUtility.UrlEncode(""))

        Dim client As WebClient
        client = New WebClient()
        client.Headers(HttpRequestHeader.ContentType) = "application/x-www-form-urlencoded"
        client.Headers(HttpRequestHeader.ContentLength) = postData.Length.ToString()

        AddHandler client.UploadStringCompleted, AddressOf client_UploadStringCompleted
        AddHandler client.UploadProgressChanged, AddressOf client_UploadProgressChanged

        client.UploadStringAsync(uri, "POST", postData.ToString())

        prog = New ProgressIndicator()
        prog.IsVisible = True
        prog.IsIndeterminate = True
        prog.Text = "Downloading...."
        SystemTray.SetProgressIndicator(Me, prog)

    End Sub

    Private Sub client_UploadProgressChanged(sender As Object, e As UploadProgressChangedEventArgs)
        'Me.txtResult.Text = "Uploading.... " & e.ProgressPercentage & "%"
    End Sub

    Private Sub client_UploadStringCompleted(sender As Object, e As UploadStringCompletedEventArgs)
        If e.Cancelled = False And e.Error Is Nothing Then

            Dim ms As New MemoryStream(Encoding.UTF8.GetBytes(e.Result))
            Dim list As New ObservableCollection(Of Member)()
            Dim serializer As New DataContractJsonSerializer(GetType(ObservableCollection(Of Member)))
            list = DirectCast(serializer.ReadObject(ms), ObservableCollection(Of Member))

            Dim myMember As New List(Of Member)

            For Each cm As Member In list
                Dim sMemberID As String = cm.MemberID.ToString()
                Dim sUsername As String = cm.Username.ToString()
                Dim sPassword As String = cm.Password.ToString()
                Dim sName As String = cm.Name.ToString()
                Dim sTel As String = cm.Tel.ToString()
                Dim sEmail As String = cm.Email.ToString()

                myMember.Add(New Member(sMemberID, sUsername, sPassword, sName, sTel, sEmail))
            Next

            Me.MemberList.ItemsSource = myMember

            prog.IsVisible = False
        End If
    End Sub

    Private Sub ClickDelete(ByVal sender As Object, ByVal e As RoutedEventArgs)

        Dim btnDel As Button = DirectCast(e.OriginalSource, Button)
        If MessageBox.Show("Are you sure?", "Delete ", MessageBoxButton.OKCancel) = MessageBoxResult.OK Then

            '*** Delete Data ***'
            Dim url As String = "http://localhost/myphp/deleteData.php"
            Dim uri As Uri = New Uri(url, UriKind.Absolute)

            Dim postData As StringBuilder = New StringBuilder()
            postData.AppendFormat("{0}={1}", "sMemberID", HttpUtility.UrlEncode(btnDel.Tag.ToString()))

            Dim client As WebClient
            client = New WebClient()
            client.Headers(HttpRequestHeader.ContentType) = "application/x-www-form-urlencoded"
            client.Headers(HttpRequestHeader.ContentLength) = postData.Length.ToString()

            AddHandler client.UploadStringCompleted, AddressOf client_DeleteUploadStringCompleted

            client.UploadStringAsync(uri, "POST", postData.ToString())

            prog = New ProgressIndicator()
            prog.IsVisible = True
            prog.IsIndeterminate = True
            prog.Text = "Deleting...."
            SystemTray.SetProgressIndicator(Me, prog)

        End If

    End Sub

    Private Sub client_DeleteUploadStringCompleted(sender As Object, e As UploadStringCompletedEventArgs)
        If e.Cancelled = False And e.Error Is Nothing Then
            prog.IsVisible = False
            MessageBox.Show("Delete Completed.", "Result", MessageBoxButton.OK)
            LoadData()
        End If
    End Sub


    <DataContract()> _
    Public Class Member

        <DataMember()> _
        Public Property MemberID() As String
            Get
                Return m_MemberID
            End Get
            Set(value As String)
                m_MemberID = value
            End Set
        End Property
        <DataMember()> _
        Public Property Username() As String
            Get
                Return m_Username
            End Get
            Set(value As String)
                m_Username = value
            End Set
        End Property
        <DataMember()> _
        Public Property Password() As String
            Get
                Return m_Password
            End Get
            Set(value As String)
                m_Password = value
            End Set
        End Property
        <DataMember()> _
        Public Property Name() As String
            Get
                Return m_Name
            End Get
            Set(value As String)
                m_Name = value
            End Set
        End Property
        <DataMember()> _
        Public Property Tel() As String
            Get
                Return m_Tel
            End Get
            Set(value As String)
                m_Tel = value
            End Set
        End Property
        <DataMember()> _
        Public Property Email() As String
            Get
                Return m_Email
            End Get
            Set(value As String)
                m_Email = value
            End Set
        End Property


        Private m_MemberID As String
        Private m_Username As String
        Private m_Password As String
        Private m_Name As String
        Private m_tel As String
        Private m_Email As String

        Public Sub New(ByVal strMemberID As String,
                       ByVal strUsername As String,
                       ByVal strPassword As String,
                       ByVal strName As String,
                       ByVal strTel As String,
                       ByVal strEmail As String)
            Me.MemberID = strMemberID
            Me.Username = strUsername
            Me.Password = strPassword
            Me.Name = strName
            Me.Tel = strTel
            Me.Email = strEmail

        End Sub

    End Class

End Class

using System;
using System.Windows;
using Microsoft.Phone.Controls;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Collections.ObjectModel;
using System.IO;
using System.Text;
using Microsoft.Phone.Shell;
using System.Windows.Controls;
using System.Net;

namespace PhoneApp
{
    public partial class MainPage : PhoneApplicationPage
    {

        // Constructor
        public MainPage()
        {
            InitializeComponent();
            Loaded += MainPage_Loaded;
        }

        ProgressIndicator prog;
        private void MainPage_Loaded(object sender, System.Windows.RoutedEventArgs e)
        {
            LoadData();
        }

        private void LoadData()
        {
            string url = "http://localhost/myphp/showAllData.php";
            Uri uri = new Uri(url, UriKind.Absolute);

            StringBuilder postData = new StringBuilder();
            postData.AppendFormat("{0}={1}", "NULL", HttpUtility.UrlEncode(""));

            WebClient client = default(WebClient);
            client = new WebClient();
            client.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
            client.Headers[HttpRequestHeader.ContentLength] = postData.Length.ToString();

            client.UploadStringCompleted += client_UploadStringCompleted;
            client.UploadProgressChanged += client_UploadProgressChanged;

            client.UploadStringAsync(uri, "POST", postData.ToString());

            prog = new ProgressIndicator();
            prog.IsVisible = true;
            prog.IsIndeterminate = true;
            prog.Text = "Downloading....";
            SystemTray.SetProgressIndicator(this, prog);

        }

        private void client_UploadProgressChanged(object sender, UploadProgressChangedEventArgs e)
        {
            //Me.txtResult.Text = "Uploading.... " & e.ProgressPercentage & "%"
        }

        private void client_UploadStringCompleted(object sender, UploadStringCompletedEventArgs e)
        {

            if (e.Cancelled == false & e.Error == null)
            {
                MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(e.Result));
                ObservableCollection<Member> list = new ObservableCollection<Member>();
                DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(ObservableCollection<Member>));
                list = (ObservableCollection<Member>)serializer.ReadObject(ms);

                List<Member> myMember = new List<Member>();

                foreach (Member cm in list)
                {
                    string sMemberID = cm.MemberID.ToString();
                    string sUsername = cm.Username.ToString();
                    string sPassword = cm.Password.ToString();
                    string sName = cm.Name.ToString();
                    string sTel = cm.Tel.ToString();
                    string sEmail = cm.Email.ToString();

                    myMember.Add(new Member(sMemberID, sUsername, sPassword, sName, sTel, sEmail));
                }

                this.MemberList.ItemsSource = myMember;

                prog.IsVisible = false;
            }
        }


        private void ClickDelete(object sender, RoutedEventArgs e)
        {
            Button btnDel = (Button)e.OriginalSource;

            if (MessageBox.Show("Are you sure?", "Delete ", MessageBoxButton.OKCancel) == MessageBoxResult.OK)
            {
                //*** Delete Data ***'
                string url = "http://localhost/myphp/deleteData.php";
                Uri uri = new Uri(url, UriKind.Absolute);

                StringBuilder postData = new StringBuilder();
                postData.AppendFormat("{0}={1}", "sMemberID", HttpUtility.UrlEncode(btnDel.Tag.ToString()));

                WebClient client = default(WebClient);
                client = new WebClient();
                client.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
                client.Headers[HttpRequestHeader.ContentLength] = postData.Length.ToString();

                client.UploadStringCompleted += client_DeleteUploadStringCompleted;

                client.UploadStringAsync(uri, "POST", postData.ToString());

                prog = new ProgressIndicator();
                prog.IsVisible = true;
                prog.IsIndeterminate = true;
                prog.Text = "Deleting....";
                SystemTray.SetProgressIndicator(this, prog);

            }

        }

        private void client_DeleteUploadStringCompleted(object sender, UploadStringCompletedEventArgs e)
        {
            if (e.Cancelled == false & e.Error == null)
            {
                prog.IsVisible = false;
                MessageBox.Show("Delete Completed.", "Result", MessageBoxButton.OK);
                LoadData();
            }
        }


        [DataContract]
        public class Member
        {
            [DataMember]
            public string MemberID { get; set; }

            [DataMember]
            public string Username { get; set; }

            [DataMember]
            public string Password { get; set; }

            [DataMember]
            public string Name { get; set; }

            [DataMember]
            public string Tel { get; set; }

            [DataMember]
            public string Email { get; set; }

            public Member(string strMemberID, string strUsername, string strPassword
                , string strName
                , string strTel
                , string strEmail)
            {
                this.MemberID = strMemberID;
                this.Username = strUsername;
                this.Password = strPassword;
                this.Name = strName;
                this.Tel = strTel;
                this.Email = strEmail;
            }

        }

    }

}