[WPF] 为Style 里的button添加鼠标点击响应事件

一个TabControl, 用的是PagedTabControl style, 在style中有个button, button在style里已经写了click事件，但是现在还需要加上一段功能，就是在响应事件之前对界面作一下判断。该怎么办呢？先看代码：

1. 控件XAML部分代码(位于文件form_loadatorigin.xaml）：

<!-- Form Body -->
<TabControl x:Name="formLoadUnload"
Style="{StaticResource PagedTabControl}"
Tag="" HorizontalAlignment="Stretch"
Grid.Row="0" Grid.RowSpan="2"
Grid.IsSharedSizeScope="True"
>

<!-- Page 1 -->
<TabItem Name="LoadUnloadPage1" Foreground="Black">
<!-- 此处为Page1页面 略去-->
</TabItem>

<!-- Page 2 -->
<TabItem Name="LoadUnloadPage2" Foreground="Black">
<!-- 此处为Page2页面 略去-->
</TabItem>
</TabControl>

2. Style PagedTabControl代码：

<Style x:Key="PagedTabControl" TargetType="{x:Type TabControl}">
<Setter Property="OverridesDefaultStyle" Value="True" />
<Setter Property="SnapsToDevicePixels" Value="True" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TabControl}">
<Grid KeyboardNavigation.TabNavigation="Local">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<TabPanel Name="PagedHeaderPanel"
Grid.Row="0"
Grid.ColumnSpan="2"
Panel.ZIndex="0"
Margin="2,0,4,0"
KeyboardNavigation.TabIndex="1"
/>
<StackPanel Grid.Column="1" Grid.Row="0" Orientation="Horizontal" Panel.ZIndex="1" Margin="0,0,50,0"
KeyboardNavigation.TabIndex="1">
<Button x:Name="PreviousPageButton"
Grid.Column="0"
Background="White">
<Button.Content>
<Image Source="/Common.WPF.Assets;component/Images/btn_left.png"/>
</Button.Content>
<Button.Style>
<Style BasedOn="{StaticResource RoundButtonStyle}" TargetType="{x:Type Button}">
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource TemplatedParent},Path=SelectedIndex}" Value="0">
<Setter Property="IsEnabled" Value="False"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard>
<Storyboard>
<Int32Animation
Storyboard.Target="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=''}"
Storyboard.TargetProperty="SelectedIndex"
By="-1" Duration="0:0:.1" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
<TextBlock VerticalAlignment="Center" Margin="10,0,10,0" Style="{StaticResource NormalText19Style}" HorizontalAlignment="Center" TextAlignment="Center" >
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} {1} of {2}">
<Binding RelativeSource="{RelativeSource TemplatedParent}" Path="Tag"/>
<Binding RelativeSource="{RelativeSource TemplatedParent}" Path="SelectedIndex" Converter="{StaticResource ZeroBasedIndexConverter}"/>
<Binding RelativeSource="{RelativeSource TemplatedParent}" Path="Items.Count"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
<Button x:Name="NextPageButton"
Background="White">
<Button.Content>
<Image Source="/Common.WPF.Assets;component/Images/btn_right.png"/>
</Button.Content>

<Button.Style>
<Style BasedOn="{StaticResource RoundButtonStyle}" TargetType="{x:Type Button}">
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource TemplatedParent},Path=SelectedIndex}" Value="Items.Count">
<Setter Property="IsEnabled" Value="False"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
<Button.Triggers>

<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard>
<Storyboard>
<Int32Animation
Storyboard.Target="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=''}"
Storyboard.TargetProperty="SelectedIndex"
By="1" Duration="0:0:.1" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
</StackPanel>
<TabPanel
Name="HeaderPanel"
Grid.Row="0"
Panel.ZIndex="1"
Height="0"
IsItemsHost="True">
</TabPanel>
<Border
Name="Border"
Grid.Row="1"
Grid.ColumnSpan="2"
BorderThickness="1"
CornerRadius="2"
KeyboardNavigation.TabNavigation="Local"
KeyboardNavigation.DirectionalNavigation="Contained"
KeyboardNavigation.TabIndex="2">
<ContentPresenter
Name="PART_SelectedContentHost"
Margin="4"
ContentSource="SelectedContent" />
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

我们需要NextPageButton添加鼠标点击，下面就是在控件的实现文件里添加的代码：

3. 在form_loadatorigin.xaml.cs文件里的实现代码：

public form_loadatorigin()
{
InitializeComponent();

this.Loaded += new RoutedEventHandler(form_loadatorigin_Loaded);
}

private void form_loadatorigin_Loaded(object sender, RoutedEventArgs e)
{
if (!IsFirstLoaded)
{
IsFirstLoaded = true;
formLoadUnload.SelectionChanged += new SelectionChangedEventHandler(formLoadUnload_SelectionChanged);

DependencyObject d1 = VisualTreeHelper.GetChild(formLoadUnload, 0);
m_NextPageButton = LogicalTreeHelper.FindLogicalNode(d1, "NextPageButton") as Button;
m_NextPageButton.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(m_NextPageButton_PreviewMouseLeftButtonDown);
}
}

void m_NextPageButton_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
e.Handled = true;
if (ValidateAndShowErrors())
{
m_NextPageButton.RaiseEvent(new RoutedEventArgs(Button.ClickEvent, m_NextPageButton));
}
}

private Button m_NextPageButton;
private bool IsFirstLoaded = false;

注意：

1. m_NextPageButton必须为成员变量，如果改成局部变量，则添加事件不会起作用。至于原因，还没有找到为什么。

2. 此为抛砖引玉之技法，如有更好的方法，还望高手不吝赐教！