【WP8】让TextBox文本支持滑动（Scroll）
通过修改样式让TextBox支持文本滑动
在Silverlight上，TextBox是有文本滚动的功能的，当TextBox的文本过长时，可以进行拖动的，TextBox使用 VerticalScrollBarVisibility 和 HorizontalScrollBarVisibility 来控制滚动条的显示
在Windows Phone上的TextBox 也拥有 VerticalScrollBarVisibility 和 HorizontalScrollBarVisibility 两个属性，但是当设置这两个属性Visible后，却发现TextBox上的文本滑动不了，下面对比Silverlight和WP上的TextBox样式
WP8上的TextBox样式如下：
<Style x:Key="TextBoxStyle1" TargetType="TextBox"> <Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilyNormal}"/> <Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMediumLarge}"/> <Setter Property="Background" Value="{StaticResource PhoneTextBoxBrush}"/> <Setter Property="Foreground" Value="{StaticResource PhoneTextBoxForegroundBrush}"/> <Setter Property="BorderBrush" Value="{StaticResource PhoneTextBoxBrush}"/> <Setter Property="SelectionBackground" Value="{StaticResource PhoneAccentBrush}"/> <Setter Property="SelectionForeground" Value="{StaticResource PhoneTextBoxSelectionForegroundBrush}"/> <Setter Property="BorderThickness" Value="{StaticResource PhoneBorderThickness}"/> <Setter Property="Padding" Value="2"/> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="TextBox"> <Grid Background="Transparent"> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="CommonStates"> <VisualState x:Name="Normal"/> <VisualState x:Name="MouseOver"/> <VisualState x:Name="Disabled"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> <VisualState x:Name="ReadOnly"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <Visibility>Collapsed</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ReadonlyBorder"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <Visibility>Visible</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ReadonlyBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ReadonlyBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxReadOnlyBrush}"/> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> </VisualStateGroup> <VisualStateGroup x:Name="FocusStates"> <VisualState x:Name="Focused"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxEditBackgroundBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxEditBorderBrush}"/> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> <VisualState x:Name="Unfocused"/> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Border x:Name="MainBorder" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Margin="{StaticResource PhoneTouchTargetOverhang}"/> <Border x:Name="ReadonlyBorder" BorderBrush="{StaticResource PhoneDisabledBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="Transparent" Margin="{StaticResource PhoneTouchTargetOverhang}" Visibility="Collapsed"/> <Border BorderBrush="Transparent" BorderThickness="{TemplateBinding BorderThickness}" Background="Transparent" Margin="{StaticResource PhoneTouchTargetOverhang}"> <ContentControl x:Name="ContentElement" BorderThickness="0" HorizontalContentAlignment="Stretch" Margin="{StaticResource PhoneTextBoxInnerMargin}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="Stretch"/> </Border> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style>
Silverlight上的TextBox样式如下（Silverlight支持文本滚动）
<ControlTemplate x:Key="ValidationToolTipTemplate"> <Grid x:Name="Root" Margin="5,0" Opacity="0" RenderTransformOrigin="0,0"> <Grid.RenderTransform> <TranslateTransform x:Name="xform" X="-25"/> </Grid.RenderTransform> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="OpenStates"> <VisualStateGroup.Transitions> <VisualTransition GeneratedDuration="0"/> <VisualTransition GeneratedDuration="0:0:0.2" To="Open"> <Storyboard> <DoubleAnimation Duration="0:0:0.2" To="0" Storyboard.TargetProperty="X" Storyboard.TargetName="xform"> <DoubleAnimation.EasingFunction> <BackEase Amplitude=".3" EasingMode="EaseOut"/> </DoubleAnimation.EasingFunction> </DoubleAnimation> <DoubleAnimation Duration="0:0:0.2" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root"/> </Storyboard> </VisualTransition> </VisualStateGroup.Transitions> <VisualState x:Name="Closed"> <Storyboard> <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root"/> </Storyboard> </VisualState> <VisualState x:Name="Open"> <Storyboard> <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="X" Storyboard.TargetName="xform"/> <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="Root"/> </Storyboard> </VisualState> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Border Background="#052A2E31" CornerRadius="5" Margin="4,4,-4,-4"/> <Border Background="#152A2E31" CornerRadius="4" Margin="3,3,-3,-3"/> <Border Background="#252A2E31" CornerRadius="3" Margin="2,2,-2,-2"/> <Border Background="#352A2E31" CornerRadius="2" Margin="1,1,-1,-1"/> <Border Background="#FFDC000C" CornerRadius="2"/> <Border CornerRadius="2"> <TextBlock Foreground="White" MaxWidth="250" Margin="8,4,8,4" TextWrapping="Wrap" Text="{Binding (Validation.Errors)[0].ErrorContent}" UseLayoutRounding="false"/> </Border> </Grid> </ControlTemplate> <Style x:Key="TextBoxStyle1" TargetType="TextBox"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="TextBox"> <Grid x:Name="RootElement"> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="CommonStates"> <VisualState x:Name="Normal"/> <VisualState x:Name="MouseOver"> <Storyboard> <ColorAnimation Duration="0" To="#FF99C1E2" Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Color)" Storyboard.TargetName="MouseOverBorder"/> </Storyboard> </VisualState> <VisualState x:Name="Disabled"> <Storyboard> <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="DisabledVisualElement"/> </Storyboard> </VisualState> <VisualState x:Name="ReadOnly"> <Storyboard> <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="ReadOnlyVisualElement"/> </Storyboard> </VisualState> </VisualStateGroup> <VisualStateGroup x:Name="FocusStates"> <VisualState x:Name="Focused"> <Storyboard> <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisualElement"/> </Storyboard> </VisualState> <VisualState x:Name="Unfocused"> <Storyboard> <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="FocusVisualElement"/> </Storyboard> </VisualState> </VisualStateGroup> <VisualStateGroup x:Name="ValidationStates"> <VisualState x:Name="Valid"/> <VisualState x:Name="InvalidUnfocused"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ValidationErrorElement"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <Visibility>Visible</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> <VisualState x:Name="InvalidFocused"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ValidationErrorElement"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <Visibility>Visible</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsOpen" Storyboard.TargetName="validationTooltip"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <system:Boolean>True</system:Boolean> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Border x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Margin="{StaticResource PhoneTouchTargetOverhang}"> <Grid> <Border x:Name="ReadOnlyVisualElement" Background="#5EC9C9C9" Opacity="0"/> <Border x:Name="MouseOverBorder" BorderBrush="Transparent" BorderThickness="1"> <ScrollViewer x:Name="ContentElement" BorderThickness="0" IsTabStop="False" Padding="{TemplateBinding Padding}"/> </Border> </Grid> </Border> <Border x:Name="DisabledVisualElement" BorderBrush="#A5F7F7F7" BorderThickness="{TemplateBinding BorderThickness}" Background="#A5F7F7F7" IsHitTestVisible="False" Opacity="0"/> <Border x:Name="FocusVisualElement" BorderBrush="#FF6DBDD1" BorderThickness="{TemplateBinding BorderThickness}" IsHitTestVisible="False" Margin="1" Opacity="0"/> <Border x:Name="ValidationErrorElement" BorderBrush="#FFDB000C" BorderThickness="1" CornerRadius="1" Visibility="Collapsed"> <ToolTipService.ToolTip> <ToolTip x:Name="validationTooltip" DataContext="{Binding RelativeSource={RelativeSource TemplatedParent}}" Placement="Right" PlacementTarget="{Binding RelativeSource={RelativeSource TemplatedParent}}" Template="{StaticResource ValidationToolTipTemplate}"> <ToolTip.Triggers> <EventTrigger RoutedEvent="Canvas.Loaded"> <BeginStoryboard> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsHitTestVisible" Storyboard.TargetName="validationTooltip"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <system:Boolean>true</system:Boolean> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> </Storyboard> </BeginStoryboard> </EventTrigger> </ToolTip.Triggers> </ToolTip> </ToolTipService.ToolTip> <Grid Background="Transparent" HorizontalAlignment="Right" Height="12" Margin="1,-4,-4,0" VerticalAlignment="Top" Width="12"> <Path Data="M 1,0 L6,0 A 2,2 90 0 1 8,2 L8,7 z" Fill="#FFDC000C" Margin="1,3,0,0"/> <Path Data="M 0,0 L2,0 L 8,6 L8,8" Fill="#ffffff" Margin="1,3,0,0"/> </Grid> </Border> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style>
通过对比TextBox的样式发现，WP8上的TextBox样式模板里面并没有ScrollViewer控件，而Silverlight中的TextBox是有ScrollViewer的，可以正常滚动，我们把WP8上的TextBox样式中的ContentControl改为ScrollViewer
<Style x:Key="TextBoxStyle2" TargetType="TextBox"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="TextBox"> <Grid Background="Transparent"> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="CommonStates"> <VisualState x:Name="Normal"/> <VisualState x:Name="MouseOver"/> <VisualState x:Name="Disabled"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> <VisualState x:Name="ReadOnly"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <Visibility>Collapsed</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ReadonlyBorder"> <DiscreteObjectKeyFrame KeyTime="0"> <DiscreteObjectKeyFrame.Value> <Visibility>Visible</Visibility> </DiscreteObjectKeyFrame.Value> </DiscreteObjectKeyFrame> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ReadonlyBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ReadonlyBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxReadOnlyBrush}"/> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> </VisualStateGroup> <VisualStateGroup x:Name="FocusStates"> <VisualState x:Name="Focused"> <Storyboard> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxEditBackgroundBrush}"/> </ObjectAnimationUsingKeyFrames> <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="MainBorder"> <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxEditBorderBrush}"/> </ObjectAnimationUsingKeyFrames> </Storyboard> </VisualState> <VisualState x:Name="Unfocused"/> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Border x:Name="MainBorder" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Margin="{StaticResource PhoneTouchTargetOverhang}"/> <Border x:Name="ReadonlyBorder" BorderBrush="{StaticResource PhoneDisabledBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="Transparent" Margin="{StaticResource PhoneTouchTargetOverhang}" Visibility="Collapsed"/> <Border BorderBrush="Transparent" BorderThickness="{TemplateBinding BorderThickness}" Background="Transparent" Margin="{StaticResource PhoneTouchTargetOverhang}"> <ScrollViewer x:Name="ContentElement" BorderThickness="0" IsTabStop="False" Padding="{TemplateBinding Padding}" Margin="{StaticResource PhoneTextBoxInnerMargin}" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch"/> </Border> </Grid> </ControlTemplate> </Setter.Value> </Setter> </Style>
测试后发现，WP8上的TextBox可以滑动了（但发现看不到ScrollBar）
控制TextBox显示文本的位置
有时候我们需要在代码中向TextBox的Text添加内容，比如表情，这时候TextBox不在编辑状态，我们添加文本后可以通过TextBox.SelectionStart去控制TextBox显示的位置，添加内容后TextBox.SelectionStart会被设置为0，如果需要显示文本的末尾，可以用 textBox.SelectionStart = textBox.Text.Length - 1;