WPF ListBox 鼠标拖拽多选

<ListBox Name="listBox" SelectionMode="Extended">

    <ListBox.Resources>

        <Style TargetType="{x:Type ListBoxItem}">

            <EventSetter Event="ListBoxItem.PreviewMouseLeftButtonDown" Handler="lbItem_PreviewMouseLeftButtonDown"/>

            <EventSetter Event="ListBoxItem.PreviewMouseUp" Handler="lbItem_PreviewMouseUp"/>

            <EventSetter Event="ListBoxItem.PreviewMouseMove" Handler="lbItem_PreviewMouseMove"/>

        </Style>

    </ListBox.Resources>

    <x:Type TypeName="DependencyObject"/>

    <x:Type TypeName="Visual"/>

    <x:Type TypeName="UIElement"/>

    <x:Type TypeName="FrameworkElement"/>

    <x:Type TypeName="Control"/>

</ListBox>

 

 

 

private bool inMouseSelectionMode = false;

private List<ListBoxItem> selectedItems = new List<ListBoxItem>();

private void lbItem_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)

{

    // MouseDown时清空已选Item

    // 同时开始"inMouseSelectionMode"

    foreach (var item in selectedItems)

    {

        item.ClearValue(ListBoxItem.BackgroundProperty);

        item.ClearValue(TextElement.ForegroundProperty);

    }

    selectedItems.Clear();

    inMouseSelectionMode = true;

}

private void lbItem_PreviewMouseUp(object sender, MouseButtonEventArgs e)

{

    // MouseUp时停止"inMouseSelectionMode"

    ListBoxItem mouseUpItem = sender as ListBoxItem;

    inMouseSelectionMode = false;

}

private void lbItem_PreviewMouseMove(object sender, MouseEventArgs e)

{

    ListBoxItem mouseOverItem = sender as ListBoxItem;

    if (mouseOverItem != null && inMouseSelectionMode && e.LeftButton == MouseButtonState.Pressed)

    {

        // Mouse所在的Item设置高亮

    
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    mouseOverItem.Background = SystemColors.HighlightBrush;

        mouseOverItem.SetValue(TextElement.ForegroundProperty, SystemColors.HighlightTextBrush);

        if (!selectedItems.Contains(mouseOverItem)) { selectedItems.Add(mouseOverItem); }

    }

}