wpf拖放以可视方式选择项目

问题描述

| 我在程序中使用拖放操作，效果很好。但是我正在使用列表框中的单词列表，当我选择一个单词并将其拖到另一个列表框中时，用户不再知道他选择了哪个单词，因为其中的“视觉”选择第一个列表框没有出现。有谁知道我如何在列表框中看到所选项目？在实施拖放操作之前，选择的单词在选择单词时会具有另一种颜色，但是在添加拖放操作后，我不再看到它了。谁能帮我？ http://img196.imageshack.us/img196/8408/imgmt.jpg

    private void lstAlleTabellen_PreviewMouseLeftButtonDown(object sender,MouseButtonEventArgs e)
    {
        startpoint = e.GetPosition(null);
    }

    private void lstAlleTabellen_MouseMove(object sender,MouseEventArgs e)
    {
        // Get the current mouse position
        System.Windows.Point mousePos = e.GetPosition(null);
        Vector diff = startpoint - mousePos;

        if (e.LeftButton == MouseButtonState.pressed &&
            Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragdistance ||
            Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragdistance)
        {
            // Get the dragged ListViewItem
            System.Windows.Controls.ListBox listAlle = sender as System.Windows.Controls.ListBox;
            ListBoxItem listItem =
                FindAnchestor<ListBoxItem>((DependencyObject)e.OriginalSource);
            Tabel tabel=new Tabel();
            try
            {
                // Find the data behind the ListViewItem
                tabel = (Tabel)listAlle.ItemContainerGenerator.
                    ItemFromContainer(listItem);


                // Initialize the drag & drop operation
                DataObject dragData = new DataObject(\"myFormat\",tabel);
                DragDrop.DoDragDrop(listItem,dragData,DragDropEffects.Move);
            }
            catch
            {
            }
        }
    }

    private static T FindAnchestor<T>(DependencyObject current) where T : DependencyObject
    {
        do
        {
            if (current is T)
            {
                return (T)current;
            }
            current = VisualTreeHelper.GetParent(current);
        }
        while (current != null);
        return null;
    }
    private void lstGekozenTabellen_dragenter(object sender,DragEventArgs e)
    {
        if (!e.Data.GetDataPresent(\"myFormat\") ||sender == e.source)
        {
            e.Effects = DragDropEffects.None;
        }
    }

    private void lstGekozenTabellen_Drop(object sender,DragEventArgs e)
    {
        try
        {
            if (e.Data.GetDataPresent(\"myFormat\"))
            {
                Tabel tabel = e.Data.GetData(\"myFormat\") as Tabel;
                System.Windows.Controls.ListBox listGekozen = sender as System.Windows.Controls.ListBox;
                listGekozen.displayMemberPath = \"naam\";
                listGekozen.SelectedValuePath = \"naam\";
                listGekozen.Items.Add(tabel);
                lTabellen.Remove(tabel);

                lstAlleTabellen.ItemsSource = null;
                lstAlleTabellen.Items.Clear();
                lstAlleTabellen.ItemsSource = lTabellen;
            }


        }
        catch { }
    }

}

    

解决方法

您可以为此使用样式触发器，例如（此处为完整解决方案）：

    <Style x:Key=\"ListItemStyle\" TargetType=\"ListViewItem\">
        <Style.Resources>
            <LinearGradientBrush x:Key=\"MouseOverBrush\" StartPoint=\"0.5,0\" EndPoint=\"0.5,1\">
                <GradientStop Color=\"#22000000\" Offset=\"0\" />
                <GradientStop Color=\"#44000000\" Offset=\"0.4\" />
                <GradientStop Color=\"#55000000\" Offset=\"0.6\" />
                <GradientStop Color=\"#33000000\" Offset=\"0.9\" />
                <GradientStop Color=\"#22000000\" Offset=\"1\" />
            </LinearGradientBrush>
        </Style.Resources>
        <Setter Property=\"Width\" Value=\"Auto\" />
        <Setter Property=\"Padding\" Value=\"0,4\" />
        <Setter Property=\"HorizontalContentAlignment\" Value=\"Stretch\" />
        <Setter Property=\"Border.BorderThickness\" Value=\"0,0.5\" />
        <Setter Property=\"Border.BorderBrush\" Value=\"LightGray\" />
        <Style.Triggers>
            <Trigger Property=\"jas:ListViewItemDragState.IsBeingDragged\" Value=\"True\">
                <Setter Property=\"FontWeight\" Value=\"DemiBold\" />
            </Trigger>
            <Trigger Property=\"jas:ListViewItemDragState.IsUnderDragCursor\" Value=\"True\">
                <Setter Property=\"Background\" Value=\"{StaticResource MouseOverBrush}\" />
            </Trigger>
        </Style.Triggers>
    </Style>