OnlineMonitorSystem/HandyControl/HandyControl_Shared/Themes/Styles/ComboBox.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:hc="clr-namespace:HandyControl.Controls">

    <Style BasedOn="{StaticResource ComboBoxBaseStyle}" TargetType="ComboBox"/>

    <Style x:Key="ComboBoxItem.Small" BasedOn="{StaticResource ComboBoxItemBaseStyle}" TargetType="ComboBoxItem">
        <Setter Property="Padding" Value="6,0" />
        <Setter Property="MinHeight" Value="20" />
    </Style>

    <Style x:Key="ComboBox.Small" BasedOn="{StaticResource ComboBoxBaseStyle}" TargetType="ComboBox">
        <Setter Property="ItemContainerStyle" Value="{StaticResource ComboBoxItem.Small}" />
        <Setter Property="MinHeight" Value="20"/>
        <Setter Property="Padding" Value="6,0"/>
    </Style>

    <Style x:Key="ComboBoxExtend" BasedOn="{StaticResource ComboBoxExtendBaseStyle}" TargetType="ComboBox"/>

    <Style x:Key="ComboBoxExtend.Small" BasedOn="{StaticResource ComboBoxExtend}" TargetType="ComboBox">
        <Setter Property="ItemContainerStyle" Value="{StaticResource ComboBoxItem.Small}" />
        <Setter Property="hc:InfoElement.MinContentHeight" Value="20"/>
        <Setter Property="hc:InfoElement.ContentHeight" Value="20"/>
        <Setter Property="hc:TitleElement.MarginOnTheLeft" Value="0,3,6,0"/>
        <Setter Property="hc:TitleElement.MarginOnTheTop" Value="6,0,0,1" />
        <Setter Property="Padding" Value="6,0"/>
        <Setter Property="MinHeight" Value="20"/>
    </Style>

    <Style BasedOn="{StaticResource ComboBoxPlusBaseStyle}" TargetType="hc:ComboBox"/>

    <Style x:Key="ComboBoxPlus.Small" BasedOn="{StaticResource ComboBoxPlusBaseStyle}" TargetType="hc:ComboBox">
        <Setter Property="ItemContainerStyle" Value="{StaticResource ComboBoxItem.Small}" />
        <Setter Property="hc:InfoElement.MinContentHeight" Value="20"/>
        <Setter Property="hc:InfoElement.ContentHeight" Value="20"/>
        <Setter Property="hc:TitleElement.MarginOnTheLeft" Value="0,3,6,0"/>
        <Setter Property="hc:TitleElement.MarginOnTheTop" Value="6,0,0,1" />
        <Setter Property="Padding" Value="6,0" />
        <Setter Property="MinHeight" Value="20"/>
    </Style>

</ResourceDictionary>