如何將滑塊值鏈接到文本塊的FontSize並將該值存儲在ApplicationData變量中

Question

我希望你能幫助我解決我的問題。我有一個簡單的地鐵應用程序。名爲myTextBlock的文本塊位於HomePageView頁面中。這是它的XAML：

<TextBlock x:Name="myTextBlock" Text="Hello" HorizontalAlignment="Center" VerticalAlignment="Top" Style="{StaticResource timeStyle}" TextAlignment="Center" FontSize="300" RenderTransformOrigin="0.5,0.5" Margin="11,55,3,0" ManipulationMode="All"> 

這是在主頁的代碼在LoadState背後：

protected override void LoadState(Object navigationParameter, Dictionary<String, Object> pageState) 
     { 
      try 
      { 
       double? myTextBlockValue = (double?)ApplicationData.Current.LocalSettings.Values["myTextBlockSize"]; 
       if (myTextBlockValue != null) 
       { 
        myTextBlock.FontSize = (double)myTextBlockValue; 
       } 
      } 
      catch 
      { 

      } 
     } 

我建了一個設置面板（魅力吧 - >設置 - >設置）命名SettingsPage其中滑塊名爲timeSlider被放置。這是它的XAML：

<Slider x:Name="timeSlider" Width="257" Minimum="1" Maximum="600" Loaded="timeSlider_Loaded" ValueChanged="timeSlider_ValueChanged" /> 

而這些滑塊加載和的ValueChanged方法放在SettingsPage代碼隱藏：

private void timeSlider_Loaded(object sender, RoutedEventArgs e) 
     { 
      var sliderIstance = sender as Slider; 
      double? storedSize = (double?)ApplicationData.Current.LocalSettings.Values["myTextBlockSize"]; 
      if (storedSize != null && storedSize != 1) 
       sliderIstance.Value = (double)storedSize; 
      else 
       sliderIstance.Value = 300; 
     } 

     private void timeSlider_ValueChanged(object sender, RangeBaseValueChangedEventArgs e) 
     { 
      var sliderIstance = sender as Slider; 
      ApplicationData.Current.LocalSettings.Values["myTextBlockSize"] = sliderIstance.Value as double?; 
      var _Frame = Window.Current.Content as Frame; 
      _Frame.Navigate(_Frame.Content.GetType()); 
      _Frame.GoBack(); 
     } 

您可以在這裏下載完整的解決方案在我的SkyDrive：https://skydrive.live.com/redir?resid=1B721133DC03E67C!7350

通過這種方式，我將myTextBlock的fontsize屬性（在HomePageView頁面中）鏈接到滑塊的值屬性（在SettingsPage頁面中），以便用戶可以在運行時更改此屬性。此外，此屬性存儲在myTextBlockSize ApplicationData變量中，以在應用程序關閉並重新打開時保留其值。

該解決方案的工作原理是：當我進入設置窗格（魅力酒吧 - >設置 - >設置），並通過滑塊更改textblock fontsize屬性，然後我回到主頁視圖並重新打開設置窗格，fontsize屬性會重新初始化爲其原始值，因此它不會保留先前（用戶選擇的）值。 你能解決我的代碼嗎？非常感謝你提前。

Answer 1

你必須在timeSlider_ValueChanged事件

private void timeSlider_ValueChanged(object sender, RangeBaseValueChangedEventArgs e) 
{ 
    var sliderIstance = sender as Slider; 
    if (sliderIstance.Value != 1) 
     ApplicationData.Current.LocalSettings.Values["myTextBlockSize"] = sliderIstance.Value as double?; 
    var _Frame = Window.Current.Content as Frame; 
    _Frame.Navigate(_Frame.Content.GetType()); 
    _Frame.GoBack(); 
}