2
這個問題has been asked已經到目前爲止還沒有答案。我發現文本框PlaceholderText作爲文本輸入之前的某些狀態信息的指示器非常有用，但默認的非包裝限制了此有用功能。製作一個TextBox PlaceholderText換行
有沒有解決方案？
A
回答
2
我會假設你正在開發一個Windows 10（WinRT）應用程序。 你需要創建一個新的風格爲您TextBox和編輯，顯示佔位符文本的元素（在這種情況下，它是CotentControl名爲PlaceholderTextContentPresenter）：
<TextBox PlaceholderText="Long text that needs to wrap">
<TextBox.Style>
<!-- Default style for Windows.UI.Xaml.Controls.TextBox -->
<Style TargetType="TextBox">
<Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}" />
<Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}" />
<Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}" />
<Setter Property="Background" Value="{ThemeResource SystemControlBackgroundAltHighBrush}" />
<Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundChromeDisabledLowBrush}" />
<Setter Property="SelectionHighlightColor" Value="{ThemeResource SystemControlHighlightAccentBrush}" />
<Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}" />
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
<Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
<Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TextBox">
<Grid>
<Grid.Resources>
<Style x:Name="DeleteButtonStyle" TargetType="Button">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid
x:Name="ButtonLayoutGrid"
Background="{ThemeResource TextBoxButtonBackgroundThemeBrush}"
BorderBrush="{ThemeResource TextBoxButtonBorderThemeBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="GlyphElement" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAccentBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ButtonLayoutGrid" Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAccentBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="GlyphElement" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAltChromeWhiteBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation
Duration="0"
Storyboard.TargetName="ButtonLayoutGrid"
Storyboard.TargetProperty="Opacity"
To="0" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<TextBlock
x:Name="GlyphElement"
HorizontalAlignment="Center"
VerticalAlignment="Center"
AutomationProperties.AccessibilityView="Raw"
FontFamily="{ThemeResource SymbolThemeFontFamily}"
FontSize="12"
FontStyle="Normal"
Foreground="{ThemeResource SystemControlForegroundChromeBlackMediumBrush}"
Text="" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Grid.Resources>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="HeaderContentPresenter" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseLowBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledTransparentBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseLowBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledChromeDisabledLowBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledChromeDisabledLowBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Normal" />
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightChromeAltLowBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Opacity">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundHoverOpacity}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Focused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlPageTextChromeBlackMediumLowBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundChromeWhiteBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Opacity">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundFocusedOpacity}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightAccentBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlForegroundChromeBlackHighBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="RequestedTheme">
<DiscreteObjectKeyFrame KeyTime="0" Value="Light" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="ButtonStates">
<VisualState x:Name="ButtonVisible">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="DeleteButton" Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="ButtonCollapsed" />
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Border
x:Name="BackgroundElement"
Grid.Row="1"
Grid.RowSpan="1"
Grid.ColumnSpan="2"
Margin="{TemplateBinding BorderThickness}"
Background="{TemplateBinding Background}"
Opacity="{ThemeResource TextControlBackgroundRestOpacity}" />
<Border
x:Name="BorderElement"
Grid.Row="1"
Grid.RowSpan="1"
Grid.ColumnSpan="2"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}" />
<ContentPresenter
x:Name="HeaderContentPresenter"
Grid.Row="0"
Grid.ColumnSpan="2"
Margin="0,0,0,8"
Content="{TemplateBinding Header}"
ContentTemplate="{TemplateBinding HeaderTemplate}"
FontWeight="Normal"
Foreground="{ThemeResource SystemControlForegroundBaseHighBrush}"
Visibility="Collapsed"
x:DeferLoadStrategy="Lazy" />
<ScrollViewer
x:Name="ContentElement"
Grid.Row="1"
Margin="{TemplateBinding BorderThickness}"
AutomationProperties.AccessibilityView="Raw"
HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
IsTabStop="False"
IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
Padding="{TemplateBinding Padding}"
VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
ZoomMode="Disabled" />
<ContentControl
x:Name="PlaceholderTextContentPresenter"
Grid.Row="1"
Grid.ColumnSpan="2"
Margin="{TemplateBinding BorderThickness}"
Foreground="{ThemeResource SystemControlPageTextBaseMediumBrush}"
IsHitTestVisible="False"
IsTabStop="False"
Padding="{TemplateBinding Padding}" >
<ContentControl.Content>
<TextBlock TextWrapping="Wrap" Text="{TemplateBinding PlaceholderText}"/>
</ContentControl.Content>
</ContentControl>
<Button
x:Name="DeleteButton"
Grid.Row="1"
Grid.Column="1"
MinWidth="34"
Margin="{ThemeResource HelperButtonThemePadding}"
VerticalAlignment="Stretch"
BorderThickness="{TemplateBinding BorderThickness}"
FontSize="{TemplateBinding FontSize}"
IsTabStop="False"
Style="{StaticResource DeleteButtonStyle}"
Visibility="Collapsed" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</TextBox.Style>
</TextBox>
我已經改變了Content屬性是TextBlock與TextWrapping屬性集。
對於其他平臺，這基本上是相同的，您只需編輯TextBox控件的默認樣式。您可以在Visual Studio本身（在XAML設計器視圖 - >右鍵單擊 - >編輯模板...）中生成它們，或者在Internet上找到它們。
謝謝。我注意到，你改變 'CONTENT = 「{TemplateBinding PlaceholderText}」' 到 哪個技巧。 但是行 ' 您能糾正您的XAML，以便我可以標記爲已回答。 –
user2921851
我編輯了我的答案。我太魯莽了。我很樂意幫助你。 –
標記爲已回答。 另外值得一提的是，最好自己定義一個樣式（方便隱藏在一個通用樣式文件中），例如： '