private InsertIndicator CreateInsertIndicator(VerticalAlignment alignment)
{
var insertIndicator = new InsertIndicator();
if (alignment == System.Windows.VerticalAlignment.Top)
{
var transform = new TranslateTransform(0d, -3.5d);
insertIndicator.RenderTransform = transform;
}
else if (alignment == System.Windows.VerticalAlignment.Bottom)
{
var transform = new TranslateTransform(15d, 3d);
insertIndicator.RenderTransform = transform;
}
insertIndicator.VerticalAlignment = alignment;
insertIndicator.IsHitTestVisible = false;
return(insertIndicator);
}
private void ShowInsertIndicator(Grid panel, InsertIndicator insertIndicator)
{
var columnCtn = panel.ColumnDefinitions.Count;
var rowCtn = panel.RowDefinitions.Count;
if (columnCtn > 1)
{
Grid.SetColumnSpan(insertIndicator, columnCtn);
}
if (rowCtn > 1)
{
Grid.SetRowSpan(insertIndicator, rowCtn);
}
panel.Children.Add(insertIndicator);
this._lastPanel = panel;
this._lastInsertIndicator = insertIndicator;
}
private void treeView_DragOver(object sender, DragEventArgs e)
{
try
{
if (_viewmodel.IsStandardDocument == false || this._isEditable || this._itemBorders == null)
{
e.Handled = true;
e.Effects = DragDropEffects.None;
return;
}
///如果当前位置位于InsertIndicator上那么直接忽略
///之前使用GetClosetParent[T]判断是否位于InsertIndicator上
///但是由于GetClosetParent[T]过于耗时，替换方法
var type = e.OriginalSource.GetType();
if (type.GetProperty("Name") != null)
{
dynamic objDynamic = e.OriginalSource;
var onname = objDynamic.Name;
if (onname == "InsertIndicatorEllipse" || onname == "InsertIndicatorGrid")
{
e.Handled = true;
return;
}
}
this.RemoveLastInsertIndicator();
this.HideIsDragInto();
var relativePosition = default(Point);
var border = this.GetClosetParentWithName <Grid>(e.OriginalSource as DependencyObject, "ItemBd");
if (border != null)
{
///拖动到一个ItemBd上面，包括每个元素的图片文本以及后面的空白的位置
relativePosition = e.GetPosition(border);
if (relativePosition.Y <= 5)
{
///如果在鼠标在ItemBd的Y坐标<=5,说明在元素的上沿
///插入指示要放置在[上一个]元素
///[上一个]元素也有两种情况：
///1，如果当前ItemBd所在的TreeViewItem是父节点的第一个元素，那么[上一个]元素是父节点
///2，如果当前ItemBd所在的TreeViewItem不是父节点的第一个元素，那么[上一个]元素是上一个兄弟节点
///统一在拖动开始前获取所有ItemBd，然后在DragOver时获取上一个节点
var prepanel = this._itemBorders.TakeWhile(x => x != border).LastOrDefault();
if (prepanel != null)
{
///上一个节点不为空
this.ShowIsDragInto(prepanel);
this._dragInfo.Parent = prepanel;
this._dragInfo.PreviousBrother = null;
if (!IsDescent(this._dragInfo.NodeViewModel, prepanel.DataContext as NodeViewModel))
{
///不是拖动到自己或者自己的子节点内
this.ShowInsertIndicator(prepanel, System.Windows.VerticalAlignment.Bottom);
}
else
{
this.ShowDisabledInsertIndicator(prepanel, System.Windows.VerticalAlignment.Bottom);
e.Handled = true;
e.Effects = DragDropEffects.None;
return;
}
}
else
{
///上一个节点为空，说明当前位置为第一个节点，插入到当前ItemBd的Top位置
this.ShowInsertIndicator(border, System.Windows.VerticalAlignment.Top);
this._dragInfo.Parent = null;
this._dragInfo.PreviousBrother = null;
}
}
else
{
///否则，插入到当前ItemBd的Bottom位置
this.ShowIsDragInto(border);
this._dragInfo.Parent = border;
this._dragInfo.PreviousBrother = null;
if (!IsDescent(this._dragInfo.NodeViewModel, border.DataContext as NodeViewModel))
{
this.ShowInsertIndicator(border, System.Windows.VerticalAlignment.Bottom);
}
else
{
this.ShowDisabledInsertIndicator(border, System.Windows.VerticalAlignment.Bottom);
e.Handled = true;
e.Effects = DragDropEffects.None;
return;
}
}
}
else
{
///拖动到TreeViewItemPanel上面
var actualPanel = GetActualTreeviewPanel(e, e.OriginalSource as DependencyObject);
if (actualPanel != null)
{
var fstchildgrid = FindVisualChildren <Grid>(actualPanel).FirstOrDefault();
if (fstchildgrid != null)
{
var insertIndicator = new InsertIndicator();
var transform = new TranslateTransform(fstchildgrid.Margin.Left + 14, 3.5d);
insertIndicator.RenderTransform = transform;
insertIndicator.VerticalAlignment = System.Windows.VerticalAlignment.Bottom;
insertIndicator.IsHitTestVisible = false;
this.ShowInsertIndicator(actualPanel, insertIndicator);
var parentPanel = this.GetClosetParentWithName <Grid>(VisualTreeHelper.GetParent(actualPanel), "TreeViewItemPanel");
if (parentPanel != null)
{
this.ShowIsDragInto(parentPanel);
this._dragInfo.Parent = parentPanel;
this._dragInfo.PreviousBrother = actualPanel;
if (IsDescent(this._dragInfo.NodeViewModel, parentPanel.DataContext as NodeViewModel))
{
insertIndicator.IsEnable = false;
e.Handled = true;
e.Effects = DragDropEffects.None;
return;
}
}
else
{
this._dragInfo.Parent = null;
this._dragInfo.PreviousBrother = actualPanel;
}
}
}
}
e.Handled = true;
e.Effects = DragDropEffects.Move;
}
catch (Exception)
{
}
}
