wpf 在数据模板中使用样式

Using styles within a data template

提问by JonWillis

I have a class called item, and it contains just two properties. I will display them on the screen as buttons with a style. This question relates to how I can style the button based on the IsSelected value, when the element I want to affect is in the style not the data template. I have already tried with a Trigger but been unable to get it to work.

我有一个名为 item 的类，它只包含两个属性。我将它们作为具有样式的按钮显示在屏幕上。这个问题与我如何根据 IsSelected 值设置按钮样式有关，当我想要影响的元素是样式而不是数据模板时。我已经尝试过使用触发器，但无法使其正常工作。

The class is below.

课程如下。

public class Item : ObservableObject
{
    private string _title;
    private bool _isSelected;

    public string Title
    {
        get { return _title; }
        set
        {
            _title = value;
            RaisePropertyChanged("Title");
        }
    }

    public bool IsSelected
    {
        get { return _isSelected; }
        set
        {
            _isSelected = value;
            RaisePropertyChanged("IsSelected");
        }
    }
}

I use a data template to display these items in a ItemsControls.

我使用数据模板在 ItemsControls 中显示这些项目。

<ItemsControl ItemsSource="{Binding Path=Items}" ItemTemplate="{StaticResource ResourceKey=ItemTemplate}">
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <StackPanel Orientation="Horizontal" />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
    </ItemsControl>

Using the following style and data template.

使用以下样式和数据模板。

<Style x:Key="ItemButton" TargetType="Button">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Border Name="ButtonBorder" BorderThickness="2,2,2,0" BorderBrush="#AAAAAA"  CornerRadius="6,6,0,0"  Margin="2,20,0,0" Background="Black">
                    <ContentPresenter
                            VerticalAlignment="Center"  
                            HorizontalAlignment="Center"/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
<DataTemplate x:Key="ItemTemplate">
    <Button Height="60" Style="{StaticResource ItemButton}" Name="Button">
        <StackPanel Orientation="Horizontal">
            <TextBlock Text="{Binding Path=Title}" 
                       HorizontalAlignment="Left" Margin="5,5,5,3" FontSize="25" Foreground="#6B6B6B" FontFamily="Arial" />
                <Button Style="{StaticResource NoChromeButton}" Margin="0,0,5,0">
                <Button.Content>
                    <Image Height="20" Source="/WpfApplication1;component/Image/dialogCloseButton.png"></Image>
                </Button.Content>
                <Button.ToolTip>
                    Close    
                </Button.ToolTip>
            </Button>
        </StackPanel>
    </Button>
</DataTemplate>

I need to change the Background of "ButtonBorder" from Black to White when IsSelected is True, on the object Item.

当 IsSelected 为 True 时，我需要在对象 Item 上将“ButtonBorder”的背景从黑色更改为白色。

I have added in a Trigger in the Data Template This does not work, I guess its because the style overrides the DataTemplate, thus the background stays white. Yet when i try to do a trigger in the style, I can't access the property IsSelected?

我在数据模板中添加了一个触发器这不起作用，我猜是因为样式覆盖了数据模板，因此背景保持白色。然而，当我尝试在样式中执行触发器时，我无法访问属性 IsSelected？

DataTemplate Trigger

数据模板触发器

    <DataTemplate.Triggers>
        <DataTrigger Binding="{Binding IsSelected}" Value="True">
            <Setter TargetName="Button" Property="Background" Value="White"/>
        </DataTrigger>
    </DataTemplate.Triggers>

Style trigger

风格触发

    <Style.Triggers>
        <DataTrigger Binding="{Binding IsSelected}" Value="True">
            <Setter Property="Background" Value="White"/>
        </DataTrigger>
    </Style.Triggers>

Am i missing something?

我错过了什么吗？

回答by Rachel

Make your ButtonBorder.Backgroundbe {TemplateBinding Background}, which means it will use whatever background color is assigned to the templated Button, then you can change your Button's background based on a Trigger

使您ButtonBorder.Backgroundbe {TemplateBinding Background}，这意味着它将使用分配给模板化按钮的任何背景颜色，然后您可以根据触发器更改按钮的背景

<Style x:Key="ItemButton" TargetType="Button">
    <Setter Property="Background" Value="Black" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Border Name="ButtonBorder" Background="{TemplateBinding Background}" ... >
                    <ContentPresenter ... "/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style x:Key="SelectableItemButton" TargetType="Button" BasedOn="{StaticResource ItemButton}">
    <Setter Property="Background" Value="Black" />
    <Style.Triggers>
        <DataTrigger Binding="{Binding IsSelected}" Value="True">
            <Setter Property="Background" Value="White"/>
        </DataTrigger>
    </Style.Triggers>
</Style>

<DataTemplate x:Key="ItemTemplate">
    <Button Height="60" Style="{StaticResource SelectableItemButton}">
        ...
    </Button>
</DataTemplate>

I'm also making a SelectableItemButtonStyle which inherits from ItemButton, and just implements the trigger

我也在制作一个SelectableItemButton继承自的样式ItemButton，并且只是实现了触发器

回答by loxxy

Shouldn't the target be "ButtonBorder" instead of "Button" in :

目标不应该是“ButtonBorder”而不是“Button”：

<Setter TargetName="Button"....

Also, to access the property IsSelectedyou need to set the TargetTypein the style ....

此外，要访问IsSelected您需要TargetType在样式中设置的属性....