如何阻止页面回弹到原始位置

Question

我在Windows Phone 7页面的内容面板网格周围实现了ScrollViewer。但是，每当我尝试向下滚动到页面底部时，只要我将手指从屏幕上移开，它就会立即回到原始位置。换句话说，滚动它并不保留它的最后位置，使滚动毫无意义。

这是我的网页代码：

<phone:PhoneApplicationPage 
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
         xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone" 
         xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" xmlns:GalaSoft_MvvmLight_Command="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WP71" x:Class="StepsForWater.Views.Submit" 
         mc:Ignorable="d" 
         d:DesignWidth="480" 
         d:DesignHeight="696" 
         FontFamily="{StaticResource PhoneFontFamilyNormal}" 
         FontSize="{StaticResource PhoneFontSizeNormal}" 
         Foreground="{StaticResource PhoneForegroundBrush}" 
         SupportedOrientations="Portrait" 
         Orientation="Portrait" 
         shell:SystemTray.IsVisible="True" 
         DataContext="{Binding Submit, Source={StaticResource Locator}}"> 

<!-- Sample code showing usage of ApplicationBar --> 
<phone:PhoneApplicationPage.ApplicationBar> 
    <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True"> 
     <shell:ApplicationBarIconButton x:Name="appbar_About" IconUri="/Images/appbar_button1.png" Text="About" Click="appbar_About_Click"/> 
     <shell:ApplicationBarIconButton x:Name="appbar_WalkRun" IconUri="/Images/appbar_button2.png" Text="Walk/Run" Click="appbar_WalkRun_Click"/>    
     <!--<shell:ApplicationBar.MenuItems> 
      <shell:ApplicationBarMenuItem x:Name="menuItem1" Text="MenuItem 1"></shell:ApplicationBarMenuItem> 
      <shell:ApplicationBarMenuItem x:Name="menuItem2" Text="MenuItem 2"></shell:ApplicationBarMenuItem> 
     </shell:ApplicationBar.MenuItems>--> 
    </shell:ApplicationBar> 
</phone:PhoneApplicationPage.ApplicationBar> 

<Grid x:Name="LayoutRoot"> 
    <Grid.RowDefinitions> 
     <RowDefinition Height="Auto" /> 
     <RowDefinition Height="*" /> 
    </Grid.RowDefinitions> 

    <Grid.Background> 
     <ImageBrush ImageSource="/StepsForWater;component/Images/submit-bg.png" /> 
    </Grid.Background> 

    <!--TitlePanel contains the name of the application and page title--> 
    <StackPanel x:Name="TitlePanel" 
       Grid.Row="0" 
       Margin="12,17,0,28"> 

     <!--<TextBlock x:Name="ApplicationTitle" 
        Text="MY APPLICATION" 
        Style="{StaticResource PhoneTextNormalStyle}" /> 
     <TextBlock x:Name="PageTitle" 
        Text="page name" 
        Margin="9,-7,0,0" 
        Style="{StaticResource PhoneTextTitle1Style}" />--> 
    </StackPanel> 

    <ScrollViewer> 
    <!--ContentPanel - place additional content here-->   
    <Grid x:Name="ContentPanel" 
      Grid.Row="1" 
      Margin="12,0,12,-241" Background="{x:Null}">    
     <TextBlock Height="30" HorizontalAlignment="Left" Margin="38,57,0,0" x:Name="tBlk_Username" Text="{Binding UserName}" VerticalAlignment="Top" /> 
     <TextBox Height="72" HorizontalAlignment="Left" Margin="27,79,0,0" x:Name="tb_UserNameVal" Text="{Binding UserNameValue, Mode=TwoWay}" VerticalAlignment="Top" Width="423" /> 
     <TextBlock Height="30" HorizontalAlignment="Left" Margin="38,169,0,0" x:Name="tBlk_Email" Text="{Binding Email}" VerticalAlignment="Top" /> 
     <TextBlock Height="30" HorizontalAlignment="Left" Margin="38,278,0,0" x:Name="tBlk_Message" Text="{Binding Message}" VerticalAlignment="Top" /> 
     <TextBox Height="72" HorizontalAlignment="Left" Margin="27,191,0,0" x:Name="tb_EmailVal" Text="{Binding EmailValue, Mode=TwoWay}" VerticalAlignment="Top" Width="423" /> 
     <TextBox Height="153" HorizontalAlignment="Left" Margin="27,300,0,0" x:Name="tb_MessageVal" Text="{Binding MessageValue, Mode=TwoWay}" VerticalAlignment="Top" Width="423" /> 
     <CheckBox Content="{Binding Location}" Height="72" HorizontalAlignment="Left" Margin="27,459,0,0" x:Name="chk_Location" VerticalAlignment="Top" /> 
     <Button Content="{Binding Submit}" Height="72" HorizontalAlignment="Left" Margin="27,761,0,0" x:Name="btn_Submit" VerticalAlignment="Top" Width="160" > 
      <i:Interaction.Triggers> 
       <i:EventTrigger EventName="Click"> 
        <GalaSoft_MvvmLight_Command:EventToCommand x:Name="SubmitClick" Command="{Binding SubmitCommand}"/> 
       </i:EventTrigger> 
      </i:Interaction.Triggers> 
     </Button>    
     <TextBlock Height="30" HorizontalAlignment="Left" Margin="50,540,0,0" Name="tBlk_PicInfo" Text="{Binding PictureInfo}" VerticalAlignment="Top" Grid.Row="1" /> 
     <Image Height="150" HorizontalAlignment="Left" Margin="50,583,0,0" Name="img_FlickrPic" Stretch="Fill" VerticalAlignment="Top" Width="200" Grid.Row="1" Source="{Binding ImageSource}"/> 
     <Button Content="Capture" Height="72" HorizontalAlignment="Left" Margin="267,0,0,138" Name="btn_Capture" VerticalAlignment="Bottom" Width="160" d:LayoutOverrides="GridBox" > 
      <i:Interaction.Triggers> 
       <i:EventTrigger EventName="Click"> 
        <GalaSoft_MvvmLight_Command:EventToCommand x:Name="CaptureClick" Command="{Binding CaptureCommand}"/> 
       </i:EventTrigger> 
      </i:Interaction.Triggers> 
     </Button> 
     </Grid>       
    </ScrollViewer> 
</Grid> 

更新：修正了我的问题，所有我需要做的就是确保我的ScrollViewer的高度比它更低真实含有格！

Answer 1

正如别人所说，你应该重新思考你的布局方式。有更清洁的选择。但要回答你的问题，有两个问题。首先是你需要在ScrollViewer上指定一个高度。

<ScrollViewer Height="760"> 
.... 
</ScrollViewer> 

第二个问题是您已应用到网格的241的负边距。简单地把它关掉。它阻止了滚动到的范围内的任何内容。

<Grid x:Name="ContentPanel" Margin="12,0,12,0"> 
.... 
</Grid> 

而且应该这样做。