尝试这个
<Window.Resources> //Put this resourse n Window.Resources or UserControl.Resources <LinearGradientBrush x:Key="NormalBrush" StartPoint="0,0" EndPoint="0,1"> <GradientBrush.GradientStops> <GradientStopCollection> <GradientStop Color="#FFDC3939" Offset="0.0"/> <GradientStop Color="#FFE80E0E" Offset="1.0"/> </GradientStopCollection> </GradientBrush.GradientStops> </LinearGradientBrush> <SolidColorBrush x:Key="WindowBackgroundBrush" Color="#FFFBE618" /> <ControlTemplate x:Key="ComboBoxToggleButton" TargetType="ToggleButton"> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition /> <ColumnDefinition Width="20" /> </Grid.ColumnDefinitions> <Border x:Name="Border" Grid.ColumnSpan="2" CornerRadius="2" Background="{StaticResource NormalBrush}" BorderThickness="1" /> <Border Grid.Column="0" CornerRadius="2,0,0,2" Margin="1" Background="{StaticResource WindowBackgroundBrush}" BorderThickness="0,0,1,0" /> <Path x:Name="Arrow" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" Data="M 0 0 L 4 4 L 8 0 Z"/> </Grid> </ControlTemplate> <ControlTemplate x:Key="ComboBoxTextBox" TargetType="TextBox"> <Border x:Name="PART_ContentHost" Focusable="False" Background="{TemplateBinding Background}" /> </ControlTemplate><Style x:Key="{x:Type ComboBox}" TargetType="ComboBox"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="ComboBox"> <Grid> <ToggleButton Name="ToggleButton" Template="{StaticResource ComboBoxToggleButton}" Grid.Column="2" Focusable="false" IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}" ClickMode="Press"> </ToggleButton> <ContentPresenter Name="ContentSite" IsHitTestVisible="False" Margin="3,3,23,3" VerticalAlignment="Center" HorizontalAlignment="Left" /> <TextBox x:Name="PART_EditableTextBox" Style="{x:Null}" Template="{StaticResource ComboBoxTextBox}" HorizontalAlignment="Left" VerticalAlignment="Center" Margin="3,3,23,3" Focusable="True" Background="Transparent" Visibility="Hidden" IsReadonly="{TemplateBinding IsReadOnly}"/> <Popup Name="Popup" Placement="Bottom" IsOpen="{TemplateBinding IsDropDownOpen}" AllowsTransparency="True" Focusable="False" PopupAnimation="Slide"> <GridName="DropDown" SnapsToDevicePixels="True" MinWidth="{TemplateBinding ActualWidth}" MaxHeight="{TemplateBinding MaxDropDownHeight}"><Border x:Name="DropDownBorder" Background="{StaticResource WindowBackgroundBrush}" BorderThickness="1"/><ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True"> <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" /></ScrollViewer> </Grid> </Popup> </Grid> </ControlTemplate> </Setter.Value> </Setter> <Style.Triggers> </Style.Triggers> </Style> </Window.Resources> <Grid> <ComboBox HorizontalAlignment="Left" Margin="256,57,0,0" VerticalAlignment="Top" Width="120"> </ComboBox> </Grid>这是可以更改的完整样式：http : //msdn.microsoft.com/zh-
cn/library/ms752094%28v=VS.85%29.aspx
