PDFOffice_Windows_exe/PDF Office/CustomControl/CompositeControl/CustomComboControl.xaml

<UserControl x:Class="PDF_Office.CustomControl.CompositeControl.CustomComboControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:PDF_Office.CustomControl.CompositeControl"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800"
             x:Name="usercontrol"
             Loaded="UserControl_Loaded"
             >
    <UserControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="../../Styles/SliderStyle.xaml"></ResourceDictionary>
                <ResourceDictionary Source="../../Styles/CustomBtnStyle.xaml"/>
            </ResourceDictionary.MergedDictionaries>

            <DataTemplate x:Key="numberData">
                <Grid>
                    <TextBlock Text="{Binding Content}" VerticalAlignment="Center" HorizontalAlignment="Center"/>
                </Grid>
            </DataTemplate>
        </ResourceDictionary>
    </UserControl.Resources>
    <Grid>
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"></ColumnDefinition>
                <ColumnDefinition Width="auto"></ColumnDefinition>
            </Grid.ColumnDefinitions>

            <Border  BorderBrush="#E2E3E6"  HorizontalAlignment="Stretch" Height="32" Margin="0,0,11,0"  BorderThickness="0">
                <Grid>
                    <ComboBox Name="comBox" BorderThickness="1" Padding="10" Background="Transparent" BorderBrush="#FFE2E3E6" 
                                  MaxDropDownHeight="200"
                            ItemTemplate="{StaticResource numberData}"
                              >
                        <ComboBox.ItemContainerStyle>
                            <Style TargetType="{x:Type ComboBoxItem}">
                                <Setter Property="Padding" Value="10 0 0 0"/>
                            </Style>
                        </ComboBox.ItemContainerStyle>
                    </ComboBox>
                    <TextBox Name="title" Background="White" FontFamily="Segoe UI" FontSize="14"  Height="20" Margin="10,0,35,0" IsReadOnly="True"
                             BorderThickness="0" VerticalAlignment="Center" TextAlignment="Left" >
                    </TextBox>
                </Grid>
            </Border>
        </Grid>
    </Grid>

</UserControl>