WPF Combobox样式

2022-12-19 15:19:21

<ControlTemplate x:Key="ComboBoxToggleButton" TargetType="{x:Type ToggleButton}">

            <Grid x:Name="grid">

                <Grid.ColumnDefinitions>

                    <ColumnDefinition />

                    <ColumnDefinition Width="20" />

                </Grid.ColumnDefinitions>

                <Rectangle Grid.ColumnSpan="2" HorizontalAlignment="Stretch" x:Name="Rectangle" VerticalAlignment="Stretch" Width="Auto" Height="Auto" RadiusX="3" RadiusY="3" Fill="LightBlue" /> <!--Combobox控件外壳-->

                <Rectangle Grid.Column="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Width="Auto" Height="Auto" RadiusX="3" RadiusY="3" Fill="Gray" /> <!--除开下拉按钮的其他部分-->

                <Border Margin="2,2,2,2" Grid.Column="1" Background="Red" Width="Auto" CornerRadius="3,3,3,3" x:Name="drop_border" />

                <Path Grid.Column="1" HorizontalAlignment="Center" Width="Auto" x:Name="Arrow" VerticalAlignment="Center" Fill="{x:Null}" Data="M0.5,0.5 L3,6.5 5.5,0.5" Stroke="Black" Margin="5,0,5,0" Height="7" StrokeThickness="2" Stretch="Fill" /> <!--Border 和 Path为下拉按钮-->

            </Grid>

            <ControlTemplate.Triggers>

                <Trigger Property="IsMouseOver" Value="true">

                    <Setter TargetName="drop_border" Property="Background" Value="White" />

                </Trigger>

            </ControlTemplate.Triggers>

        </ControlTemplate>

        <ControlTemplate x:Key="ComboBoxTextBox" TargetType="{x:Type TextBox}">

            <Border x:Name="PART_ContentHost" Focusable="False" Background="{TemplateBinding Background}" />

        </ControlTemplate>

        <Style TargetType="{x:Type ComboBox}">

            <Setter Property="SnapsToDevicePixels" Value="true" />

            <Setter Property="Template">

                <Setter.Value>

                    <ControlTemplate TargetType="{x:Type ComboBox}">

                        <Border BorderBrush="Orange" x:Name="border">

                            <Grid x:Name="grid">

                                <ToggleButton Template="{StaticResource ComboBoxToggleButton}" x:Name="ToggleButton" Focusable="false" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" ClickMode="Press" />

                                <ContentPresenter HorizontalAlignment="Left" x:Name="ContentSite" VerticalAlignment="Center" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" IsHitTestVisible="False" />

                                <TextBox Visibility="Hidden" Margin="2,2,22,2" x:Name="PART_EditableTextBox" Style="{x:Null}" VerticalAlignment="Center" Focusable="True" IsReadOnly="{TemplateBinding IsReadOnly}" Foreground="Black" HorizontalAlignment="Stretch" Background="Azure" /> <!--文本输入框，当IsEditable为true 才显示-->

                                <Popup IsOpen="{TemplateBinding IsDropDownOpen}" Placement="Bottom" x:Name="Popup" Focusable="False" AllowsTransparency="True" PopupAnimation="Slide">

                                    <Grid MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{TemplateBinding ActualWidth}" x:Name="DropDown" SnapsToDevicePixels="True">

                                        <Border x:Name="DropDownBorder" Background="WhiteSmoke" CornerRadius="3,3,3,3" />

                                        <ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto" CanContentScroll="True" Foreground="{StaticResource {x:Static SystemColors.ActiveCaptionTextBrushKey}}">

                                            <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />

                                        </ScrollViewer>

                                    </Grid>

                                </Popup>

                            </Grid>

                        </Border>

                        <ControlTemplate.Triggers>

                            <Trigger Property="HasItems" Value="false">

                                <Setter Property="MinHeight" Value="95" TargetName="DropDownBorder" />

                            </Trigger>

                            <Trigger Property="IsGrouping" Value="true">

                                <Setter Property="ScrollViewer.CanContentScroll" Value="false" />

                            </Trigger>

                            <Trigger Property="AllowsTransparency" SourceName="Popup" Value="true">

                                <Setter Property="Margin" Value="0,2,0,0" TargetName="DropDownBorder" />

                            </Trigger>

                            <Trigger Property="IsEditable" Value="true">

                                <Setter Property="IsTabStop" Value="false" />

                                <Setter Property="Visibility" Value="Visible" TargetName="PART_EditableTextBox" />

                                <Setter Property="Visibility" Value="Hidden" TargetName="ContentSite" />

                            </Trigger>

                        </ControlTemplate.Triggers>

                    </ControlTemplate>

                </Setter.Value>

            </Setter>

        </Style>

一直没搞懂Combobox具体是怎么设计的，今天抽空研究了一下，终于看懂了，主要有3个控件组成，ToggleButton，TextBox 和Popup，

ToggleButton：整个控件是由ToggleButton铺满的HorizontalAlignment="Stretch"，ToggleButton里面由一个Rectangle铺满，设置Combobox的圆角，边框及背景颜色，然后宽度20px的Border，path 为下拉按钮样式，点击combobox下拉按钮实际是点击ToggleButton

TextBox ：当IsEditable为True，会把Textbox 显示出来，Textbox是覆盖在ToggleButton之上的，注意应设置HorizontalAlignment="Stretch"，这样才会把Textbox铺满，网上很多设置的是Left，很不好选中TextBox，其次还应设置Margin="2,2,22,2"，距右边22px，这样才不能遮挡出下拉按钮

Popup：用于显示ComboboxItem

码农公寓

相关文章