basta aggiungere sotto codici menzione nel Windows Resource/UserControl, aumenterà automaticamente la dimensione predefinita del [] casella di controllo all'interno di un controllo Xaml.
<Style x:Key="FocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle Margin="2" SnapsToDevicePixels="true" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" StrokeThickness="1" StrokeDashArray="1 2"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<SolidColorBrush x:Key="OptionMark.Static.Background" Color="#FFFFFFFF"/>
<SolidColorBrush x:Key="OptionMark.Static.Border" Color="#FF707070"/>
<Style x:Key="OptionMarkFocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle Margin="14,0,0,0" SnapsToDevicePixels="true" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" StrokeThickness="1" StrokeDashArray="1 2"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<SolidColorBrush x:Key="OptionMark.MouseOver.Background" Color="#FFF3F9FF"/>
<SolidColorBrush x:Key="OptionMark.MouseOver.Border" Color="#FF5593FF"/>
<SolidColorBrush x:Key="OptionMark.MouseOver.Glyph" Color="#FF212121"/>
<SolidColorBrush x:Key="OptionMark.Disabled.Background" Color="#FFE6E6E6"/>
<SolidColorBrush x:Key="OptionMark.Disabled.Border" Color="#FFBCBCBC"/>
<SolidColorBrush x:Key="OptionMark.Disabled.Glyph" Color="#FF707070"/>
<SolidColorBrush x:Key="OptionMark.Pressed.Background" Color="#FFD9ECFF"/>
<SolidColorBrush x:Key="OptionMark.Pressed.Border" Color="#FF3C77DD"/>
<SolidColorBrush x:Key="OptionMark.Pressed.Glyph" Color="#FF212121"/>
<SolidColorBrush x:Key="OptionMark.Static.Glyph" Color="#FF212121"/>
<Style TargetType="{x:Type CheckBox}">
<Setter Property="FocusVisualStyle" Value="{StaticResource FocusVisual}"/>
<Setter Property="Background" Value="{StaticResource OptionMark.Static.Background}"/>
<Setter Property="BorderBrush" Value="{StaticResource OptionMark.Static.Border}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<Grid x:Name="templateRoot" Background="Transparent" SnapsToDevicePixels="True">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Border x:Name="checkBoxBorder" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="1" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<Grid x:Name="markGrid">
<Path x:Name="optionMark" Data="F1 M 9.97498,1.22334L 4.6983,9.09834L 4.52164,9.09834L 0,5.19331L 1.27664,3.52165L 4.255,6.08833L 8.33331,1.52588e-005L 9.97498,1.22334 Z "
Fill="{StaticResource OptionMark.Pressed.Glyph}" Margin="5" Opacity="0" Stretch="Uniform"/>
<Rectangle x:Name="indeterminateMark" Fill="{StaticResource OptionMark.Static.Glyph}" Margin="2" Opacity="0"/>
</Grid>
</Border>
<ContentPresenter x:Name="contentPresenter" Grid.Column="1" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasContent" Value="true">
<Setter Property="FocusVisualStyle" Value="{StaticResource OptionMarkFocusVisual}"/>
<Setter Property="Padding" Value="4,-1,0,0"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Background" TargetName="checkBoxBorder" Value="{StaticResource OptionMark.MouseOver.Background}"/>
<Setter Property="BorderBrush" TargetName="checkBoxBorder" Value="{StaticResource OptionMark.MouseOver.Border}"/>
<Setter Property="Fill" TargetName="optionMark" Value="{StaticResource OptionMark.MouseOver.Glyph}"/>
<Setter Property="Fill" TargetName="indeterminateMark" Value="{StaticResource OptionMark.MouseOver.Glyph}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" TargetName="checkBoxBorder" Value="{StaticResource OptionMark.Disabled.Background}"/>
<Setter Property="BorderBrush" TargetName="checkBoxBorder" Value="{StaticResource OptionMark.Disabled.Border}"/>
<Setter Property="Fill" TargetName="optionMark" Value="{StaticResource OptionMark.Disabled.Glyph}"/>
<Setter Property="Fill" TargetName="indeterminateMark" Value="{StaticResource OptionMark.Disabled.Glyph}"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Background" TargetName="checkBoxBorder" Value="{StaticResource OptionMark.Pressed.Background}"/>
<Setter Property="BorderBrush" TargetName="checkBoxBorder" Value="{StaticResource OptionMark.Pressed.Border}"/>
<Setter Property="Fill" TargetName="optionMark" Value="{StaticResource OptionMark.Pressed.Glyph}"/>
<Setter Property="Fill" TargetName="indeterminateMark" Value="{StaticResource OptionMark.Pressed.Glyph}"/>
</Trigger>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Opacity" TargetName="optionMark" Value="1"/>
<Setter Property="Opacity" TargetName="indeterminateMark" Value="0"/>
</Trigger>
<Trigger Property="IsChecked" Value="{x:Null}">
<Setter Property="Opacity" TargetName="optionMark" Value="0"/>
<Setter Property="Opacity" TargetName="indeterminateMark" Value="1"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
fonte
2018-01-17 11:16:14
Forse questo aiuterà: http://stackoverflow.com/questions/9087063/changing-the-size-of-a-checkbox-and-the-check-mark-in-it – robertk