WPF Listview SelectionChanged事件 [英] WPF Listview SelectionChanged event

问题描述

我有一个ListView绑定到ItemsSource，并且SelectionChanged事件在加载/数据绑定事件上触发?我认为这是因为选择了默认"项，即索引0.

I have a ListView binding to an ItemsSource and the SelectionChanged event is firing on the load/databound events? I assume that it is because a 'default' items ie index 0 is selected.

如何禁用此功能?

推荐答案

感谢您的答复.

当我在SelectionChanged事件上放置一个断点时，它会在屏幕完全加载之前中断程序.您还将在列表中看到第一行随后被选中".正如您在代码中看到的那样，我没有绑定到SelectedIndexValue.列表的DataContext是ReadonlyCollection

When I put a breakpoint on the SelectionChanged event, it breaks proceedings there before the screen is fully loaded. You will also see that the first row is 'selected' afterwards on the list. I am not binding to a SelectedIndexValue as you can see in the code. The DataContext for the list is a ReadonlyCollection

在您的SelectionChanged事件中，您可以看到我通知其他对象要加载与所选项目相关的数据.我只希望在选择一个而不是设置一个默认值时发生这种情况.我必须要代表类似数据的这些ListView，但是在加载时，都必须选择一个项目.

In my SelectionChanged event as you can see I notify other objects to be loaded with data relating to the selected item. I only want this to happen when one is selected but not a default one to be set. I have to of these ListViews representing similar data but on loaded none must have an item selected.

我注意到在Listview的属性窗口上，默认的Selected索引设置为-1.我什至可以将其设置为List_Loaded事件的代码，但是到那时，第一个SelectionChanged已经发生了.

I have noticed that the default Selected index is set to -1 on the properties window for the Listview. I can even set this is code on the List_Loaded event, but by then the first SelectionChanged has happened already.

<ListView PreviewMouseDown="ActiveCasesView_MouseDown" x:Name="ActiveCasesView"
                     DataContext="{StaticResource ActiveCasesViewSource}"
                     ItemsSource="{Binding}"
                     ItemTemplate="{StaticResource CasesItemTemplate}"
                     SelectionMode="Single"
                     SelectionChanged="ActiveCasesView_SelectionChanged"
                     ScrollViewer.CanContentScroll="True" 
                     ScrollViewer.VerticalScrollBarVisibility="Auto" >
</ListView>

private void ActiveCasesView_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (mouseClicked)
            if (e.AddedItems.Count > 0)
                App.Messenger.NotifyColleagues(App.MSG_SELECT_ACTIVE_CASE, ((CaseViewModel)ActiveCasesView.SelectedItem).CaseNumber);
    }

我添加了PreviewMouseDown来设置一个指示器，该指示器指示我在SelectionChanged事件中单击了列表视图.这确实有帮助，但我不认为这是最佳解决方案.

I added the PreviewMouseDown to set an indicator that I have clicked on the listview in the SelectionChanged event. This does help but I'm not convinced that its the best solution.

谢谢 佩特鲁斯

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