上位机_WPF系列总结（触发器）

当达到了出发的条件，执行设定的响应，可以是样式、数据变化、动画等。触发器的类型有：

Trigger:检测依赖属性的变化，触发器生效

<Window.Resources>
        <Style x:Key="TestStyle" TargetType="Button">
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Foreground" Value="Red" />
                </Trigger>
                <Trigger Property="IsMouseOver" Value="False">
                    <Setter Property="Foreground" Value="Blue" />
                </Trigger>
            </Style.Triggers>
        </Style>
</Window.Resources>

MultiTrigger:多个条件的设置、达到满足条件、触发器生效

<Window.Resources>
        <Style x:Key="TestStyle" TargetType="Button">
            <Style.Triggers>
                <MultiTrigger>
                    <MultiTrigger.Conditions>
                        <Condition Property="IsMouseOver" Value="true"/>
                        <Condition Property="IsFocused" Value="true"/>
                    </MultiTrigger.Conditions>
                    <MultiTrigger.Setters>
                        <Setter Property="FontSize" Value="20"/>
                    </MultiTrigger.Setters>
                </MultiTrigger>
            </Style.Triggers>
        </Style>
</Window.Resources>

DataTrigger:数据发生变化，触发器生效

    <Window.Resources>
        <Style x:Key="TestStyle" TargetType="TextBox">
            <Style.Triggers>
                <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=Self},Path=Text}" Value="测试">
                    <Setter Property="Background" Value="Red"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

MultiDataTrigger:多个数据发生变化，触发器生效

<Window.Resources>
        <Style x:Key="TestStyle" TargetType="TextBox">
            <Setter Property="Background" Value="Pink" />
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding RelativeSource={RelativeSource Mode=Self}, Path=Text}" Value="测试" />
                        <Condition Binding="{Binding RelativeSource={RelativeSource Mode=Self}, Path=IsFocused}" Value="true" />
                    </MultiDataTrigger.Conditions>
                    <MultiDataTrigger.Setters>
                        <Setter Property="Background" Value="Red" />
                        <Setter Property="FontSize" Value="20" />
                    </MultiDataTrigger.Setters>
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

EventTrigger：事件触发器，触发了某类事件，触发器生效

 <Window.Resources>
        <Style x:Key="TestStyle" TargetType="Button">
            <Setter Property="Background" Value="Pink" />
            <Style.Triggers>
                <EventTrigger  RoutedEvent="MouseEnter">
                    <EventTrigger.Actions>
                        <BeginStoryboard>
                            <Storyboard>
                                <ColorAnimation To="Purple" Storyboard.TargetProperty="(Control.Foreground).(SolidColorBrush.Color)"/>
                            </Storyboard>
                        </BeginStoryboard>
                    </EventTrigger.Actions>
                </EventTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>

事件触发器有些不同的是，它触发执行的是一段动画，并且是通过RoutedEvent来执行要监视的事件