WPF触发器的使用
WPF中定义了五个触发器类：Trigger、MultiTrigger、DataTrigger、multiDataTrigger、EventTrigger。下面我来介绍一下怎么使用这几个触发器的使用方法。
Trriger(单一条件的触发器):
<Page x:Class="StyleTest.Trigger" 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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300" Title="Trigger"> <Page.Resources> <Style x:Key="smallText"> <Setter Property="Control.Foreground" Value="blue"/> <Setter Property="Control.FontSize" Value="20"/> <Setter Property="Control.FontFamily" Value="Times new Roman"/> <Setter Property="Control.FontWeight" Value="Bold"/> <Style.Triggers> <!--这里使用了触发器,当鼠标移过控件的时候，控件的风格发生改变--> <Trigger Property="Control.IsMouseOver" Value="True"> <Setter Property="Control.Foreground" Value="red"/> <Setter Property="Control.FontSize" Value="24"/> </Trigger> </Style.Triggers> </Style> </Page.Resources> <StackPanel> <TextBlock Style="{StaticResource smallText}">旅望因高尽</TextBlock> <TextBlock Style="{StaticResource smallText}">乡心遇物悲</TextBlock> <TextBlock Style="{StaticResource smallText}">故林归宿处</TextBlock> <TextBlock Style="{StaticResource smallText}">一叶下梧桐</TextBlock> <Button Style="{StaticResource smallText}">旅思</Button> </StackPanel> </Page>
MultiTrigger(多条件的触发器):
<Page x:Class="StyleTest.Multitrigger" 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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300" Title="Multitrigger"> <Page.Resources> <Style x:Key="smallText"> <Setter Property="Control.Foreground" Value="blue"/> <Setter Property="Control.FontSize" Value="20"/> <Setter Property="Control.FontFamily" Value="Times New Roman"/> <Setter Property="Control.FontWeight" Value="Bold"/> <Style.Triggers> <Trigger Property="Control.IsMouseOver" Value="True"> <Setter Property="Control.Foreground" Value="red"/> </Trigger> <MultiTrigger> <!--定义触发器--> <MultiTrigger.Conditions> <Condition Property="Control.IsMouseOver" Value="True"/> <!--通过Condition定义触发条件--> <Condition Property="Button.IsPressed" Value="True"/> <!--通过Condition定义触发条件--> </MultiTrigger.Conditions> <Setter Property="Control.Foreground" Value="gray"/> <Setter Property="Control.FontStyle" Value="Italic"/> </MultiTrigger> </Style.Triggers> </Style> </Page.Resources> <StackPanel> <Button Style="{StaticResource smallText}">床前明月光</Button> <Button Style="{StaticResource smallText}">疑是地上霜</Button> <Button Style="{StaticResource smallText}">举头望明月</Button> <Button Style="{StaticResource smallText}">低头思故乡</Button> </StackPanel> </Page>
DataTrigger(数据触发器):DataTrigger和MultiDataTriffer这一对触发器和Trigger和MultiTrigger非常类似。但是DataTrigger多了一个Binding属性，其语法如下：
<DataTrigger Binding="{Binding ElementName=控件名，path=空间中的相应属性}" value="相关属性的值">
如：
<Page x:Class="StyleTest.DataTrigger" 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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300" Title="DataTrigger"> <Page.Resources> <Style x:Key="smallText"> <Setter Property="Control.Foreground" Value="Black"/> <Setter Property="Control.FontSize" Value="24"/> <Setter Property=" Control.FontFamily" Value="Times New Roman"/> <Setter Property="Control.FontWeight" Value="Regular"/> <Style.Triggers> <DataTrigger Binding="{Binding ElementName=italicFont, Path=IsChecked}" Value="True"> <!--这里绑定控件的名称，及控件属性--> <Setter Property=" Control.FontStyle" Value="Italic"/> <!--当该控件触发该事件的时候，则所有控件的字体样式变为斜体--> </DataTrigger> <DataTrigger Binding="{Binding ElementName=boldFont, Path=IsChecked}" Value="True"> <Setter Property="Control.FontStyle" Value="Normal"/> </DataTrigger> <DataTrigger Binding="{Binding ElementName=redFont, Path=IsChecked}" Value="True"> <Setter Property=" Control.Foreground" Value="Red"/> </DataTrigger> <DataTrigger Binding="{Binding ElementName=blueFont, Path=IsChecked}" Value="True"> <Setter Property="Control.Foreground" Value="Blue"/> </DataTrigger> <DataTrigger Binding="{Binding ElementName=btnBold, Path=IsPressed}" Value=" True"> <Setter Property="Control.FontSize" Value="12"/> </DataTrigger> </Style.Triggers> </Style> </Page.Resources> <StackPanel> <GroupBox> <Grid> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition /> <ColumnDefinition /> </Grid.ColumnDefinitions> <RadioButton Name="italicFont" Grid.Row="0" Grid.Column="0">斜体</RadioButton> <RadioButton Name="boldFont" Grid.Row="0" Grid.Column="1">正常</RadioButton> <RadioButton Name="redFont" Grid.Row="1" Grid.Column="0">红色</RadioButton> <RadioButton Name="blueFont" Grid.Row="1" Grid.Column="1">蓝色</RadioButton> </Grid> </GroupBox> <TextBlock Style="{StaticResource smallText}">床前明月光</TextBlock> <TextBlock Style="{StaticResource smallText}">疑是地上霜</TextBlock> <TextBlock Style="{StaticResource smallText}">举头望明月</TextBlock> <TextBlock Style="{StaticResource smallText}">低头思故乡</TextBlock> <Button x:Name="btnBold" Style="{StaticResource smallText}">粗体</Button> </StackPanel> </Page>