Datepicker WPFToolkit：显示截断的月份

Question

我遇到了datepicker的问题。 当我点击日期选择器时，月份被截断，图像中的显示方式。

Image of my problem

<toolkit:DatePicker x:Name="datePickerDataToFatturaSATA" Height="25" Grid.Row="1" Grid.Column="1"></toolkit:DatePicker>

这是实际的网格：

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition></RowDefinition>
        <RowDefinition></RowDefinition>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="100"></ColumnDefinition>
        <ColumnDefinition></ColumnDefinition>
        <ColumnDefinition></ColumnDefinition>
    </Grid.ColumnDefinitions>
    <Label Content="Da" Margin="10,0,0,0" Grid.Column="0" Grid.Row="0"></Label>
    <toolkit:DatePicker x:Name="datePickerDataFromFattura" Height="25" Grid.Row="0" Grid.Column="1"></toolkit:DatePicker>
    <Label Content="A" Margin="10,0,0,0" Grid.Column="0" Grid.Row="1"></Label>
    <toolkit:DatePicker x:Name="datePickerDataToFattura" Height="25" Grid.Row="1" Grid.Column="1"></toolkit:DatePicker>
    <Button x:Name="InviaFattura" Grid.Row="1" Grid.Column="2" Width="150" Content="Invia Fattura" Style="{DynamicResource RedButtonStyle}" Click="InviaFattura_Click"></Button>
</Grid>

请帮忙！