WPF - 拖放 - 装饰器在控件之外消失

Question

我正在使用 WPF 创建两个 ListView 并实现拖放功能。 ( ListView 内和 ListView 间)

我发现了一个有趣的帖子 here这样做的。

但是，有一个问题。当我从 listView1 中拖动一个 listviewitem 时，我只在 listView1 中看到装饰器(幻影图像)。当我想将 listviewItem 放到 ListView2 上时，我也必须在那里看到装饰器。基本上，装饰器只出现在拖动操作开始的 listView 上。一旦它在 listView 之外，它就会消失。

我做了一些研究，但找不到使装饰器在启动拖动的控件之外可见的方法。

谁能帮我提点建议？

Answer 1

连接 GiveFeedback 事件以更新 ListView 之外的装饰器位置。从下面的示例和方法更新了 ListView 属性(并且在 listview_DragLeave 方法中您不想折叠装饰器):

    /// <summary>
    /// Gets/sets the ListView whose dragging is managed.  This property
    /// can be set to null, to prevent drag management from occuring.  If
    /// the ListView's AllowDrop property is false, it will be set to true.
    /// </summary>
    public ListView ListView
    {
        get { return listView; }
        set
        {
            if( this.IsDragInProgress )
                throw new InvalidOperationException( "Cannot set the ListView property during a drag operation." );

            if( this.listView != null )
            {
                #region Unhook Events

                this.listView.PreviewMouseLeftButtonDown -= listView_PreviewMouseLeftButtonDown;
                this.listView.PreviewMouseMove -= listView_PreviewMouseMove;
                this.listView.DragOver -= listView_DragOver;
                this.listView.DragLeave -= listView_DragLeave;
                this.listView.DragEnter -= listView_DragEnter;
                this.listView.GiveFeedback -= listView_GiveFeedback;
                this.listView.Drop -= listView_Drop;

                #endregion // Unhook Events
            }

            this.listView = value;

            if( this.listView != null )
            {
                if( !this.listView.AllowDrop )
                    this.listView.AllowDrop = true;

                #region Hook Events

                this.listView.PreviewMouseLeftButtonDown += listView_PreviewMouseLeftButtonDown;
                this.listView.PreviewMouseMove += listView_PreviewMouseMove;
                this.listView.DragOver += listView_DragOver;
                this.listView.DragLeave += listView_DragLeave;
                this.listView.DragEnter += listView_DragEnter;
                this.listView.GiveFeedback += listView_GiveFeedback;
                this.listView.Drop += listView_Drop;

                #endregion // Hook Events
            }
        }
    }

    void listView_GiveFeedback(object sender, GiveFeedbackEventArgs e)
    {
        if (this.ShowDragAdornerResolved)
            this.UpdateDragAdornerLocation();
    }