检查一个ObservableCollection，如果显示一个替代的xaml！ [英] Check if a ObservableCollection, and if so display an alternative xaml!

问题描述

我有一个 ListView ，绑定到 ObservableCollection 。此外，我列出了 ObservableCollection 中的所有项目。现在，有没有一个很好的方法来检查 ObservableCollection 是否为空，并显示一个替代的xaml？

I have a ListView with a binding to a ObservableCollection. Further I am listing out all items in the ObservableCollection. Now, Is there a good way to check if the ObservableCollection is empty, and the display an alternative xaml?

推荐答案

可以使用ListView的HasItems依赖属性。使用触发器，当属性为false时，可以更改ControlTemplate。例如：

You can use the HasItems dependency property of the ListView. With a trigger, when the property is false, you can change the ControlTemplate. Here is as example:

<ListView ItemsSource="{Binding Items}">
  <ListView.Style>
    <Style TargetType="{x:Type ListView}">
      <Style.Triggers>
        <Trigger Property="HasItems" Value="False">
          <Setter Property="Template">
            <Setter.Value>
              <ControlTemplate TargetType="{x:Type ListView}">
                <Border SnapsToDevicePixels="true" 
                        Background="{TemplateBinding Background}" 
                        BorderBrush="{TemplateBinding BorderBrush}" 
                        BorderThickness="{TemplateBinding BorderThickness}">
                  <TextBlock Text="No items"
                             HorizontalAlignment="Center"
                             VerticalAlignment="Center"/>
                </Border>
              </ControlTemplate>
            </Setter.Value>
          </Setter>
        </Trigger>
      </Style.Triggers>
    </Style>
  </ListView.Style>
</ListView>

这篇关于检查一个ObservableCollection，如果显示一个替代的xaml！的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！