Custom Datepicker Style WPF

Introduction

This tip is about how to change dafault style and size of datepicker in WPF.

Using the Code

To change default datepicker style, we need to create a new style for datepicker in WPF as given below:

<Style x:Key="DatePickerStyle1" TargetType="{x:Type DatePicker}">
        <Setter Property="Foreground" Value="#FF333333"/>
        <Setter Property="IsTodayHighlighted" Value="True"/>
        <Setter Property="SelectedDateFormat" Value="Short"/>
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="Padding" Value="2"/>
        <Setter Property="BorderBrush">
            <Setter.Value>
                <LinearGradientBrush EndPoint=".5,0" StartPoint=".5,1">
                    <GradientStop Color="#FFA3AEB9" Offset="0"/>
                    <GradientStop Color="#FF8399A9" Offset="0.375"/>
                    <GradientStop Color="#FF718597" Offset="0.375"/>
                    <GradientStop Color="#FF617584" Offset="1"/>
                </LinearGradientBrush>
            </Setter.Value>
        </Setter>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type DatePicker}">
                    <Border BorderBrush="{TemplateBinding BorderBrush}" 
                    BorderThickness="{TemplateBinding BorderThickness}" 
                    Background="{TemplateBinding Background}" 
                    Padding="{TemplateBinding Padding}">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <DoubleAnimation Duration="0" To="1" 
                                        Storyboard.TargetProperty="Opacity" 
                                        Storyboard.TargetName="PART_DisabledVisual"/>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Grid x:Name="PART_Root" 
                        HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                        VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
                            <Grid.Resources>
                                <SolidColorBrush x:Key="DisabledBrush" 
                                Color="#A5FFFFFF"/>
                                <ControlTemplate x:Key="DropDownButtonTemplate" 
                                TargetType="{x:Type Button}">
                                    <Grid>
                                        <VisualStateManager.VisualStateGroups>
                                            <VisualStateGroup x:Name="CommonStates">
                                                <VisualStateGroup.Transitions>
                                                    <VisualTransition GeneratedDuration="0"/>
                                                    <VisualTransition GeneratedDuration="0:0:0.1"
                                                    To="MouseOver"/>
                                                    <VisualTransition GeneratedDuration="0:0:0.1" 
                                                    To="Pressed"/>
                                                </VisualStateGroup.Transitions>
                                                <VisualState x:Name="Normal"/>
                                                <VisualState x:Name="MouseOver">
                                                    <Storyboard>
                                                        <ColorAnimation Duration="0" 
                                                        To="#FF448DCA" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (SolidColorBrush.Color)" 
                                                        Storyboard.TargetName="Background"/>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (GradientBrush.GradientStops)[3].
                                                        (GradientStop.Color)" 
                                                        Storyboard.TargetName="BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#7FFFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
							Storyboard.TargetProperty="
                                                        (Border.Background).
							(GradientBrush.GradientStops)[2].
                                                        (GradientStop.Color)" 
                                                        Storyboard.TargetName="BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#CCFFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
							Storyboard.TargetProperty=
                                                        "(Border.Background).
                                                        (GradientBrush.GradientStops)[1].
                                                        (GradientStop.Color)" Storyboard.TargetName=
                                                        "BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#F2FFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                    </Storyboard>
                                                </VisualState>
                                                <VisualState x:Name="Pressed">
                                                    <Storyboard>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (SolidColorBrush.Color)" 
                                                        Storyboard.TargetName="Background">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#FF448DCA"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                        <DoubleAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty=
                                                        "(UIElement.Opacity)" 
                                                        Storyboard.TargetName="Highlight">
                                                            <SplineDoubleKeyFrame KeyTime="0" 
                                                            Value="1"/>
                                                        </DoubleAnimationUsingKeyFrames>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (GradientBrush.GradientStops)[1].
                                                        (GradientStop.Color)" 
                                                        Storyboard.TargetName="BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#EAFFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (GradientBrush.GradientStops)[2].
                                                        (GradientStop.Color)" 
                                                        Storyboard.TargetName="BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#C6FFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (GradientBrush.GradientStops)[3].
                                                        (GradientStop.Color)" 
                                                        Storyboard.TargetName="BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#6BFFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                        <ColorAnimationUsingKeyFrames BeginTime="0" 
                                                        Duration="00:00:00.001" 
                                                        Storyboard.TargetProperty="(Border.Background).
                                                        (GradientBrush.GradientStops)[0].
                                                        (GradientStop.Color)" 
                                                        Storyboard.TargetName="BackgroundGradient">
                                                            <SplineColorKeyFrame KeyTime="0" 
                                                            Value="#F4FFFFFF"/>
                                                        </ColorAnimationUsingKeyFrames>
                                                    </Storyboard>
                                                </VisualState>
                                                <VisualState x:Name="Disabled"/>
                                            </VisualStateGroup>
                                        </VisualStateManager.VisualStateGroups>
                                        <Grid Background="#11FFFFFF" 
                                        FlowDirection="LeftToRight" 
                                        HorizontalAlignment="Center" Height="45" 
                                        Margin="0" VerticalAlignment="Center" 
                                        Width="45">
                                            <Grid.ColumnDefinitions>
                                                <ColumnDefinition Width="20*"/>
                                                <ColumnDefinition Width="20*"/>
                                                <ColumnDefinition Width="20*"/>
                                                <ColumnDefinition Width="20*"/>
                                            </Grid.ColumnDefinitions>
                                            <Grid.RowDefinitions>
                                                <RowDefinition Height="23*"/>
                                                <RowDefinition Height="19*"/>
                                                <RowDefinition Height="19*"/>
                                                <RowDefinition Height="19*"/>
                                            </Grid.RowDefinitions>
                                            <Border x:Name="Highlight" 
                                            BorderBrush="#FF45D6FA" 
                                            BorderThickness="1" Grid.ColumnSpan="4" 
                                            CornerRadius="0,0,1,1" Margin="-1" 
                                            Opacity="0" Grid.Row="0" 
                                            Grid.RowSpan="4"/>
                                            <Border x:Name="Background" 
                                            BorderBrush="#FFFFFFFF" 
                                            BorderThickness="1" Background="#FF1F3B53" 
                                            Grid.ColumnSpan="4" CornerRadius=".5" 
                                            Margin="0,-1,0,0" Opacity="1" 
                                            Grid.Row="1" Grid.RowSpan="3"/>
                                            <Border x:Name="BackgroundGradient" 
                                            BorderBrush="#BF000000" 
                                            BorderThickness="1" Grid.ColumnSpan="4" 
                                            CornerRadius=".5" Margin="0,-1,0,0" 
                                            Opacity="1" Grid.Row="1" 
                                            Grid.RowSpan="3">
                                                <Border.Background>
                                                    <LinearGradientBrush EndPoint=".7,1" 
                                                    StartPoint=".7,0">
                                                        <GradientStop Color="#FFFFFFFF" 
                                                        Offset="0"/>
                                                        <GradientStop Color="#F9FFFFFF" 
                                                        Offset="0.375"/>
                                                        <GradientStop Color="#E5FFFFFF" 
                                                        Offset="0.625"/>
                                                        <GradientStop Color="#C6FFFFFF" 
                                                        Offset="1"/>
                                                    </LinearGradientBrush>
                                                </Border.Background>
                                            </Border>
                                            <Rectangle Grid.ColumnSpan="4" 
                                            Grid.RowSpan="1" StrokeThickness="1">
                                                <Rectangle.Fill>
                                                    <LinearGradientBrush EndPoint="0.3,-1.1" 
                                                    StartPoint="0.46,1.6">
                                                        <GradientStop Color="#FF4084BD"/>
                                                        <GradientStop Color="#FFAFCFEA" 
                                                        Offset="1"/>
                                                    </LinearGradientBrush>
                                                </Rectangle.Fill>
                                                <Rectangle.Stroke>
                                                    <LinearGradientBrush EndPoint="0.48,-1" 
                                                    StartPoint="0.48,1.25">
                                                        <GradientStop Color="#FF494949"/>
                                                        <GradientStop Color="#FF9F9F9F" 
                                                        Offset="1"/>
                                                    </LinearGradientBrush>
                                                </Rectangle.Stroke>
                                            </Rectangle>
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                                            Fill="#FF2F2F2F" HorizontalAlignment="Center" 
                                            Margin="4,3,4,3" Grid.Row="1" 
                                            Grid.RowSpan="3" RenderTransformOrigin="0.5,0.5" 
                                            Stretch="Fill" VerticalAlignment="Center"/>-->
                                            <TextBlock Margin="2,0" Grid.Row="1" 
                                            Grid.RowSpan="3" Grid.ColumnSpan="4" 
                                            Grid.Column="0" 
                                            Text="{Binding Source={x:Static System:DateTime.Now}, 
                                            StringFormat=dd}" HorizontalAlignment="Center" 
                                            VerticalAlignment="Center" FontSize="18" 
                                            FontFamily="Arial Bold" />
                                            <Ellipse Grid.ColumnSpan="4" 
                                            Fill="#FFFFFFFF" HorizontalAlignment="Center" 
                                            Height="3" StrokeThickness="0" 
                                            VerticalAlignment="Center" Width="3"/>
                                            <Border x:Name="DisabledVisual" 
                                            BorderBrush="#B2FFFFFF" BorderThickness="1" 
                                            Grid.ColumnSpan="4" CornerRadius="0,0,.5,.5" 
                                            Opacity="0" Grid.Row="0" 
                                            Grid.RowSpan="4"/>
                                        </Grid>
                                    </Grid>
                                </ControlTemplate>
                            </Grid.Resources>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*"/>
                                <ColumnDefinition Width="50"/>
                            </Grid.ColumnDefinitions>
                            <Button x:Name="PART_Button" Grid.Column="1" 
                            Foreground="{TemplateBinding Foreground}" 
                                Focusable="False" HorizontalAlignment="Center"
                                 Margin="3,0,3,0" Grid.Row="0" 
                                 Template="{StaticResource DropDownButtonTemplate}" 
                                 VerticalAlignment="Center" />
                            <DatePickerTextBox x:Name="PART_TextBox" Grid.Column="0" 
                            Focusable="{TemplateBinding Focusable}" 
                            HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                                               Grid.Row="0" 
                                               VerticalContentAlignment="
                                               {TemplateBinding VerticalContentAlignment}" 
                                               FontSize="{TemplateBinding FontSize}"/>
                            <Grid x:Name="PART_DisabledVisual" 
                            Grid.ColumnSpan="2" Grid.Column="0" 
                            IsHitTestVisible="False" Opacity="0" 
                            Grid.Row="0">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="*"/>
                                    <ColumnDefinition Width="Auto"/>
                                </Grid.ColumnDefinitions>
                                <Rectangle Grid.Column="0" Fill="#A5FFFFFF" 
                                RadiusY="1" Grid.Row="0" RadiusX="1"/>
                                <Rectangle Grid.Column="1" Fill="#A5FFFFFF" 
                                Height="18" Margin="3,0,3,0" 
                                RadiusY="1" Grid.Row="0" 
                                RadiusX="1" Width="19"/>
                                <Popup x:Name="PART_Popup" AllowsTransparency="
                                True" Placement="Bottom" 
                                PlacementTarget="{Binding ElementName=PART_TextBox}" 
                                StaysOpen="False"/>
                            </Grid>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <DataTrigger Binding="{Binding Source={x:Static 
                        SystemParameters.HighContrast}}" Value="false">
                            <Setter Property="Foreground" 
                            TargetName="PART_TextBox" Value="{Binding Foreground, 
                            RelativeSource={RelativeSource TemplatedParent}}"/>
                        </DataTrigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

Now, we can use this style in 'DatePicker' control as:

Style="{StaticResource DatePickerStyle1}"

This style is setting current date on calendar icon automatically. To show default calendar icon, you need to comment given below line and uncomment commented line.

<TextBlock Margin="2,0" Grid.Row="1" 
Grid.RowSpan="3" Grid.ColumnSpan="4" 
Grid.Column="0" 
Text="{Binding Source={x:Static System:DateTime.Now}, 
StringFormat=dd}" 
HorizontalAlignment="Center" VerticalAlignment="Center" 
FontSize="18" FontFamily="Arial Bold" />

You can modify style as needed.