#眉標=Silverlight
#副標=Silverlight開發技術（10）
#大標= Silverlight 2.0資料繫結技術與IsolatedStorage
#作者=文／圖	董大偉


　　
==<box>===========
程式1
<TextBox Height="29" Margin="101,112,124,0" VerticalAlignment="Top" Text="{Binding Name, Mode=TwoWay}" TextWrapping="Wrap" x:Name="txb_name" FontSize="16">    	
==<end>==============




==<反灰>===========
控件名稱.DataContext = Object
==<end>==============



==<box>===========
程式2
    '一筆資料的結構
    Class PhoneBookItem
        'Name屬性
        Private _Name As String
        Property Name() As String
            Get
                Return _Name
            End Get
            Set(ByVal value As String)
                _Name = value
            End Set
        End Property

(…略…)
    End Class
==<end>==============




==<box>===========
程式3
Dim PhoneBookRec As New PhoneBookItem With {.Name = "David", .Tel = "0912345678"}
txb_name.DataContext = PhoneBookRec
==<end>==============





==<box>===========
程式4
    '一筆資料的結構
    Class PhoneBookItem
        Implements System.ComponentModel.INotifyPropertyChanged
        'Name屬性
        Private _Name As String
        Property Name() As String
            Get
                Return _Name
            End Get
            Set(ByVal value As String)
                _Name = value
                RaiseEvent PropertyChanged(Me, New System.ComponentModel.PropertyChangedEventArgs("Name"))
            End Set
        End Property
(…略…)
        '實作
        Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
    End Class
==<end>==============




===<反灰>=============
    '通訊錄陣列(內含多筆資料)
    Dim PhoneBooks() As PhoneBookItem
    Dim DataIdx As Integer = 0
==<end>==============




==<box>===========
程式5
    '顯示下一筆
Private Sub Btn_Next_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Btn_Next.Click
        DataIdx += 1
        If DataIdx > PhoneBooks.Length - 1 Then DataIdx -= 1
        ShowData()
    End Sub
    '顯示上一筆
Private Sub Btn_previous_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Btn_previous.Click
        DataIdx -= 1
        If DataIdx < 0 Then DataIdx = 0
        ShowData()
    End Sub
   '依照DataIdx顯示資料
    Sub ShowData()
        Me.lbl_idx.Text = "第" & DataIdx + 1 & "筆  共" & PhoneBooks.Length & "筆"
        Me.txb_name.DataContext = PhoneBooks(DataIdx)
        Me.txb_Tel.DataContext = PhoneBooks(DataIdx)
    End Sub
==<end>==============



==<box>===========
程式6
'通訊錄集合
Dim PhoneBookCollectionValue As System.Collections.ObjectModel.ObservableCollection(Of PhoneBookItem)
    Public ReadOnly Property PhoneBookCollection() As System.Collections.ObjectModel.ObservableCollection(Of PhoneBookItem)
        Get
            If PhoneBookCollectionValue Is Nothing Then
                '如果不存在(第一次調用)則建立物件實體
                PhoneBookCollectionValue = New System.Collections.ObjectModel.ObservableCollection(Of PhoneBookItem)
            End If
            Return PhoneBookCollectionValue
        End Get
    End Property
==<end>==============





==<box>===========
程式7
<ListBox  ItemsSource="{Binding Mode=OneWay}" Margin="29,0,48,19" VerticalAlignment="Bottom" x:Name="ListBox1" FontSize="16" Height="120">
              <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal" >
                        <TextBlock Margin="0,0,10,0" Text="{Binding Name}" />
                        <TextBlock Text="{Binding Tel}" />
                    </StackPanel>
                </DataTemplate>
               </ListBox.ItemTemplate>
    	</ListBox>
==<end>==============




==<box>===========
程式8
'動態設定PhoneBookCollection作為ListBox的資料來源
Me.ListBox1.DataContext = PhoneBookCollection
'新增三筆測試資料
PhoneBookCollection.Add(New PhoneBookItem With {.Name = "董大偉", .Tel = "0911223344"})
PhoneBookCollection.Add(New PhoneBookItem With {.Name = "董小偉", .Tel = "0911223345"})
PhoneBookCollection.Add(New PhoneBookItem With {.Name = "林小妙", .Tel = "0911223346"})
PhoneBookCollection.Add(New PhoneBookItem With {.Name = "張小春", .Tel = "0911223347"})
PhoneBookCollection.Add(New PhoneBookItem With {.Name = "沈中保", .Tel = "0911223348"})
==<end>==============




==<box>===========
程式9
'建立store
Dim store = System.IO.IsolatedStorage.IsolatedStorageFile.GetUserStoreForApplication()
'建立虛擬的檔案
Dim fs = store.CreateFile("Mydata.dat")
'建立檔案寫入的串流物件
Dim sw As IO.StreamWriter = New IO.StreamWriter(fs)
Dim buf As String = ""
'將記憶體中的資料組成字串
　　For Each Item As PhoneBookItem In PhoneBooks
　　buf += Item.Name + Chr(0) + Item.Tel
　　buf += vbCr
　　Next
'寫入檔案中
　　sw.Write(buf)
　　sw.Close()
　　fs.Close()
==<end>==============




==<box>===========
程式10
'建立store
Dim store = System.IO.IsolatedStorage.IsolatedStorageFile.GetUserStoreForApplication()
'如果找不到先前儲存的檔案
　　If store.FileExists("Mydata.dat") = False Then
'則直接進行資料初始化
　　initData()
　　Exit Function
　　End If
'開始讀檔
　　Dim fs = store.OpenFile("Mydata.dat", IO.FileMode.Open)
'透過串流機制讀檔
　　Dim sr As IO.StreamReader = New IO.StreamReader(fs)
'將讀取出的資料放入暫存位置
　　Dim buf As String = sr.ReadToEnd
　　Dim lines() As String
　　lines = buf.Split(vbCr)
　　ReDim PhoneBooks(lines.Length - 2)
　　Dim idx As Integer
Try
'進行parse並且填入通訊錄陣列
　　For Each line As String In lines
　　If line.Trim <> "" Then
　　PhoneBooks(idx) = New PhoneBookItem
　　Dim items() As String = line.Split(Chr(0))
　　PhoneBooks(idx).Name = items(0)
　　PhoneBooks(idx).Tel = items(1)
　　End If
　　idx += 1
　　Next
　　Catch ex As Exception
　　'資料初始化
　　initData()
　　Windows.Browser.HtmlPage.Window.Alert("讀取資料有誤!!!")
　　End Try
　　sr.Close()
　　fs.Close()
==<end>==============




==<box>===========
程式11
    Function initData() As Boolean
        '資料初始化
        ReDim Preserve PhoneBooks(10)
        '為每一筆記錄建立實體
        For i = 0 To PhoneBooks.Length - 1
            PhoneBooks(i) = New PhoneBookItem()
        Next
    End Function
==<end>==============