Question

我正在使用WPF创建两个ListView并实现拖放功能。（列表内查看和列表间查看）

我找到了一篇有趣的帖子here。

然而，有一个问题。当我从listView1拖动listviewitem时，我只在listView1中看到了adorner（ghost图像）。当我想在ListView2上删除listviewItem时，我必须在那里看到它的装饰。基本上，装饰器仅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，无法找到一种方法，让装饰体可以在控件的外部显示。

有人可以帮我提一些建议吗？

Answer 1

将GiveFeedback事件连接起来，以更新列表视图之外的装配工位置。从下面的示例和方法更新了ListView属性（并且在listview_DragLeave方法中，您不希望折叠装饰器）：

    /// <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();
    }

WPF - 拖放 - Adorner disappers在控件之外

1 个答案: