/// <summary>
/// 在结点被收缩起来时，应该它的子结点的所有数据在_objectItems中对应的项都移除。
/// </summary>
/// <param name="treeNode"></param>
private void OnNodeCollapsed(TreeGridRow treeNode)
{
//处理 LazyLoading
//结点被折叠后事件。
//如果懒加载开启后，则在折叠时清空所有子结点。
//不处理根结点。
if (treeNode != this.RootNode)
{
//更新布局
var itemKey = GetId(treeNode.DataContext);
_renderExpansion.Remove(itemKey);
if (this.IsLazyLoading && this.ClearCollapsedNodes && treeNode.Items.Count > 0)
{
//deregisters listeners for all ancestors
if (this.ObserveChildItems)
{
_monitor.RemoveNodes(treeNode.Items);
}
treeNode.ItemsSource = null;
TreeGridHelper.CreateDummyItem(treeNode);
//TODO do we have collapsed event if all childs are being filtered?
//if yes, we need to set the dummy nodes visibility depending
//on the filtered childs (visible if at least 1 visible child)
}
}
}
/// <summary>
/// 为指定的结点应用 <see cref="RowStyle"/> 样式。
///
/// 子类重写此方法用于应用自定义样式。
/// </summary>
/// <param name="treeNode">The node to be styled.</param>
private void ApplyNodeStyle(TreeGridRow treeNode)
{
var style = this.RowStyle;
if (style != null)
{
treeNode.Style = style;
}
}
//DummyItem 意思是展开树节点时，显示子节点正在加载中的一个临时树节点。
/// <summary>
/// Checks whether a given tree node contains a dummy node to
/// ensure it's rendered with an expander, and removes the node.
/// </summary>
/// <param name="treeNode">The node to be checked for dummy
/// child nodes.</param>
internal static void ClearDummyChildNode(TreeGridRow treeNode)
{
////if the item has never been expanded yet, it contains a dummy
////node - replace that one and insert real data
//if (ContainsDummyNode(treeNode))
//{
// treeNode.Items.Clear();
//}
}
//DummyItem 意思是展开树节点时，显示子节点正在加载中的一个临时树节点。
/// <summary>
/// Checks whether a given tree node contains a dummy node to
/// ensure it's rendered with an expander, and removes the node.
/// </summary>
/// <param name="treeNode">The node to be checked for dummy
/// child nodes.</param>
internal static void ClearDummyChildNode(TreeGridRow treeNode)
{
////if the item has never been expanded yet, it contains a dummy
////node - replace that one and insert real data
//if (ContainsDummyNode(treeNode))
//{
// treeNode.Items.Clear();
//}
}
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
var rowPresenter = ItemsControl.ItemsControlFromItemContainer(this) as TreeGridCellsPresenter;
if (rowPresenter != null)
{
this._row = rowPresenter.Row;
}
}
/// <summary>
/// 树型控件中的 Id 获取方法不能直接使用 Id，而是应该：
/// 尽量使用 TreeId，不支持时，再使用实体自己的 Id。
/// </summary>
/// <param name="item"></param>
/// <returns></returns>
private object GetId(TreeGridRow item)
{
var entity = item.DataContext;
if (entity == null)
{
throw new InvalidOperationException("这个 TreeGridRow 还没有绑定实体，获取 Id 失败。");
}
return(GetId(entity));
}
private void RefreshRowNo(TreeGridRow row)
{
//目前为了简单起见，只支持表格模式下有行号。（因为在树型模式下，行号应该使用递归遍历后计算生成。）
if (this.OnlyGridMode)
{
//不能直接使用 DataItemsSource，这是因为可能界面会对集合进行排序。
//var item = GetEntity(row);
//var rowNo = this.DataItemsSource.IndexOf(item) + 1;
//row.RowNo = rowNo;
row.RowNo = this.ItemContainerGenerator.IndexFromContainer(row) + 1;
}
}
/// <summary>
/// 尽量展开所有目标行的父行，并让目标行处于可视范围内。
/// </summary>
/// <param name="item">要显示的行对应的数据。</param>
/// <returns>返回是否成功显示该数据对应的行。</returns>
public bool ExpandToView(object item)
{
bool success = false;
if (item != null)
{
//从最上层父开始搜索对应的生成的行，如果已经生成，则直接展开该行，
//如果该行还没有生成，则在渲染布局中加入该id，该行在接下来生成时会自动展开。
var parents = this.GetParentItemList(item);
bool stopFindingRow = false;
TreeGridRow lastParentRow = null;
foreach (var parent in parents)
{
_renderExpansion.Add(GetId(parent));
if (!stopFindingRow)
{
var parentRow = this.FindRow(parent);
if (parentRow == null)
{
stopFindingRow = true;
}
else
{
lastParentRow = parentRow;
parentRow.IsExpanded = true;
}
}
}
//没有停止搜索，说明所有行都已经生成。
if (!stopFindingRow)
{
var selectedRow = this.SelectedRow;
if (selectedRow != null)
{
selectedRow.BringIntoView();
success = true;
}
}
//如果目标行并没有成功显示，则把最后可见的父行显示出来。
if (!success && lastParentRow != null)
{
lastParentRow.BringIntoView();
}
}
return(success);
}
/// <summary>
/// Copy from TreeView class.
/// </summary>
/// <param name="data"></param>
/// <param name="newRow"></param>
/// <param name="selected"></param>
internal void ChangeSelection(object data, TreeGridRow newRow, bool selected)
{
//同步本对象的 SelectedItem 属性。
if (selected)
{
this.SelectedItem = data;
}
else
{
if (this.SelectedItem == data)
{
this.SelectedItem = null;
}
}
}
/// <summary>
/// 设置行对应的选中状态属性
/// </summary>
/// <param name="row"></param>
/// <param name="isSelected"></param>
internal void ModifyRowProperty(TreeGridRow row, bool isSelected)
{
if (this.IsChecking)
{
row.SetIsCheckedField(isSelected);
}
else
{
//然后，需要设置 TreeListItem.IsSelected 属性。
//否则，会造成内部使用的 TreeView 的 SelectedItem 属性不变，但是高亮的状态已经被清除，
//这时用户再次点击该行时，TreeView 的 SelectedItemChanged 事件不会发生，
//也就不会发生整个 MTTG 的 SelectedItem 处理流程，造成无法选中该行。
//具体情况见 bug：http://ipm.grandsoft.com.cn/issues/247260
row.SetIsSelectedField(isSelected);
}
}
private void OnNodeExpanded(TreeGridRow treeNode)
{
//处理 LazyLoading
//结点被展开后事件
//完成懒加载时的结点创建工作，并设置各结点的 Filter 属性。
object item = treeNode.DataContext;
if (item != null)
{
//布局
var itemKey = GetId(item);
_renderExpansion.Add(itemKey);
var nodeItems = treeNode.Items;
//懒加载状态下，创建结点。
if (this.IsLazyLoading)
{
TreeGridHelper.ClearDummyChildNode(treeNode);
if (nodeItems.Count == 0)
{
var childItems = this.GetChildItems(item);
treeNode.ItemsSource = childItems;
//刷新以排序
if (nodeItems.NeedsRefresh)
{
nodeItems.Refresh();
}
}
}
if (nodeItems.Count == 0)
{
//如果结点没有数据，则不需要展开它。
treeNode.IsExpanded = false;
_renderExpansion.Remove(itemKey);
}
}
}
/// <summary>
/// Copies the <see cref="SortDescription"/> elements of
/// the <see cref="NodeSortDescriptions"/> collection to
/// a currently processed tree node. This method is being
/// invoked during the initialization of a given node, and
/// if the <see cref="NodeSortDescriptions"/> property
/// is changed at runtime.<br/>
/// If the <see cref="ItemCollection.SortDescriptions"/>
/// collection of the submitted <paramref name="node"/> is
/// not empty, it will be cleared.<br/>
/// This method is always being invoked, even if the
/// <see cref="NodeSortDescriptions"/> dependency property
/// is null. If you want to apply a custom sorting mechanism,
/// simply override this method.
/// </summary>
/// <param name="node">The currently processed node, if any.
/// This parameter is null if sort parameters should be set
/// on the tree's <see cref="ItemsControl.Items"/>
/// collection itself.
/// </param>
private void ApplySorting(TreeGridRow node)
{
//check whether we're sorting on node or tree level
var items = node == null ? this.Items : node.Items;
using (items.DeferRefresh())
{
//clear existing sort directions, if there are any
items.SortDescriptions.Clear();
//copy new sort directions
if (this.NodeSortDescriptions != null)
{
foreach (var sd in this.NodeSortDescriptions)
{
items.SortDescriptions.Add(sd);
}
}
}
}
private void FindViewPort(TreeGridRow row)
{
var itemsControl = row.ParentItemsControl;
if (itemsControl != null)
{
var scrollViewer = MSInternal.GetScrollHost(itemsControl);
if (scrollViewer != null && scrollViewer.CanContentScroll)
{
var itemsHost = MSInternal.GetItemsHost(itemsControl);
if (itemsHost is VirtualizingPanel)
{
this._viewPort = scrollViewer.Template.FindName(PART_ScrollContentPresenter, scrollViewer) as FrameworkElement;
if (this._viewPort == null)
{
this._viewPort = scrollViewer;
}
}
}
}
}
/*********************** 代码块解释 *********************************
*
* 树结点的选择事件处理
*
* 基类的此方法以一种防止 TreeView 重入的方式来同步 this.SelectedItem 到 TreeView.SelecteItem 上。
* 并在最后调用 this.OnSelectedItemChanged 方法，以抛出路由事件。
*
* 注意这三个方法的顺序：
* OnTreeViewSelectedItemChanged
* OnSelectedItemPropertyChanged
* RaiseSelectedItemChanged
*
**********************************************************************/
/// <summary>
/// Copy from TreeView class.
/// </summary>
/// <param name="collapsed"></param>
internal void HandleSelectionOnCollapsed(TreeGridRow collapsed)
{
using (this.SelectionProcess.TryEnterProcess(TGSelectionProcess.Row_Collapsed))
{
if (this.SelectionProcess.Success)
{
//目前只支持在单选的时候，提供此功能。
if (this.SelectParentOnCollapsed && this.SelectionModel.InnerItems.Count == 1)
{
var selectedRow = this.SelectedRow;
if (selectedRow != null && selectedRow != collapsed)
{
//检查 collapsed 是否为 selectedRow 的父行。
bool selectionInCollapsed = false;
for (var parent = selectedRow; parent != null; parent = parent.ParentRow)
{
//找到 collasped 对象
if (parent == collapsed)
{
selectionInCollapsed = true;
break;
}
}
if (selectionInCollapsed)
{
this.ChangeSelection(collapsed.DataContext, collapsed, true);
if (selectedRow.IsKeyboardFocusWithin)
{
selectedRow.Focus();
return;
}
}
}
}
}
}
}
/// <summary>
/// 设置某行的选择状态，并级联选择
/// </summary>
/// <param name="row"></param>
/// <param name="value"></param>
internal void CheckRowWithCascade(TreeGridRow row, bool value)
{
if (!this.IsCheckingEnabled)
{
return;
}
var entity = row.DataContext;
this.CheckingModel.MarkSelected(row, value);
this.RasieCheckChanged(entity, value);
//CascadeParent 模式下，需要把所有父对象选中。
if (value && this.NeedCascade(CheckingCascadeMode.CascadeParent))
{
object parent = this.GetParentItem(entity);
while (parent != null)
{
var parentRow = this.FindRow(parent);
if (parentRow == null || parentRow.IsChecked)
{
break;
}
this.CheckingModel.MarkSelected(parentRow, true);
this.RasieCheckChanged(parent, true);
parent = this.GetParentItem(parent);
}
}
//CascadeChildren 模式下，需要把所有子对象选中。
if (this.NeedCascade(CheckingCascadeMode.CascadeChildren))
{
this.CheckChildrenRecur(entity, value);
}
}
/// <summary>
/// Removes listener for an item that is represented
/// by a given <paramref name="node"/> from the cache, and also
/// processes all the node's descendants recursively.
/// </summary>
/// <param name="node">The node to be removed.</param>
public void UnregisterListeners(TreeGridRow node)
{
lock (this)
{
//try to get the represented item
object item = node.DataContext;
if (item == null)
{
return;
}
//get the item's observed child collection and
//deregister it
var itemKey = tree.GetId(item);
RemoveCollectionFromCache(itemKey);
foreach (TreeGridRow childNode in node.Items)
{
//recursively deregister descendants by
//removing all child nodes
UnregisterListeners(childNode);
}
}
}
public TreeGridRowAutomationPeer(TreeGridRow owner)
: base(owner)
{
this._owner = owner;
}
/// <summary>
/// 设置某行的“选中”状态
///
/// 维护两个底层属性：一个是选择项 List，一个是 row 的选择状态属性。
/// </summary>
/// <param name="row"></param>
/// <param name="isSelected">是“选中”状态还是“未选中”状态。</param>
internal void MarkSelected(TreeGridRow row, bool isSelected)
{
this.ModifyList(row.DataContext, isSelected);
this.ModifyRowProperty(row, isSelected);
}
internal static bool IsDummyItem(TreeGridRow item)
{
return false;
//return TreeGrid.GetEntity(item) == null;
}
/// <summary>
/// Validates whether a given node contains a single dummy item,
/// which was added to ensure the submitted tree node renders
/// an expander.
/// </summary>
/// <param name="treeNode">The tree node to be validated.</param>
/// <returns>True if the node contains a dummy item.</returns>
internal static bool ContainsDummyNode(TreeGridRow treeNode)
{
return false;
//return treeNode.Items.Count == 1 && TreeGrid.GetEntity(((TreeGridRow)treeNode.Items[0])) == null;
}
/// <summary>
/// 树型控件中的 Id 获取方法不能直接使用 Id，而是应该：
/// 尽量使用 TreeId，不支持时，再使用实体自己的 Id。
/// </summary>
/// <param name="item"></param>
/// <returns></returns>
private object GetId(TreeGridRow item)
{
var entity = item.DataContext;
if (entity == null) throw new InvalidOperationException("这个 TreeGridRow 还没有绑定实体，获取 Id 失败。");
return GetId(entity);
}
/// <summary>
/// 开始编辑某行。
/// </summary>
/// <param name="row"></param>
/// <param name="focusCell">编辑后，应该首先进入编辑状态的单元格。</param>
public bool TryEditRow(TreeGridRow row, TreeGridCell focusCell)
{
return(this.TryEditRow(row, null, focusCell));
}
/// <summary>
/// Validates whether a given node contains a single dummy item,
/// which was added to ensure the submitted tree node renders
/// an expander.
/// </summary>
/// <param name="treeNode">The tree node to be validated.</param>
/// <returns>True if the node contains a dummy item.</returns>
internal static bool ContainsDummyNode(TreeGridRow treeNode)
{
return(false);
//return treeNode.Items.Count == 1 && TreeGrid.GetEntity(((TreeGridRow)treeNode.Items[0])) == null;
}
/// <summary>
/// 开始编辑某行。
/// </summary>
/// <param name="row"></param>
/// <param name="editingEventArgs">引发编辑的事件参数。</param>
/// <param name="focusCell">编辑后，应该首先进入编辑状态的单元格。</param>
internal bool TryEditRow(TreeGridRow row, RoutedEventArgs editingEventArgs, TreeGridCell focusCell)
{
var success = false;
if (!this.IsReadOnly && this.EditingMode == TreeGridEditingMode.Row)
{
var item = row.DataContext;
var selectedItems = this.SelectionModel.InnerItems;
//由于点击任何一行的该列都会发生此事件，所以需要检测如果当前只选择了一列
if (selectedItems.Count == 1 && item == selectedItems[0])
{
//先退出之前行的编辑状态。
if (this._editingItem != item)
{
this.ExitRowEditing();
this._editingItem = item;
}
//focused 表示是否已经有单元格设置了焦点。
bool focused = focusCell != null;
var mouseArgs = editingEventArgs as MouseButtonEventArgs;
//设置所有单元格的编辑状态，及焦点。
var cells = row.TraverseCells();
foreach (var cell in cells)
{
//设置单元格的编辑状态
if (!cell.IsEditing && cell.Column.CanEdit(this._editingItem))
{
cell.SetIsEditingField(true);
}
//如果成功设置单元格的编辑状态，而且还没有设置单元格焦点，
//那么就通过鼠标的坐标来判断是否需要设置当前单元格的焦点。
if (!focused && mouseArgs != null && cell.IsEditing && cell.VisibleOnVirtualizing)
{
var position = mouseArgs.GetPosition(cell);
var cellPosition = new Rect(cell.RenderSize);
if (cellPosition.Contains(position))
{
cell.FocusOnEditing(editingEventArgs);
focused = true;
}
}
}
if (focusCell != null)
{
focusCell.FocusOnEditing(editingEventArgs);
}
//标记事件已经处理，防止事件继续冒泡导致引发 TreeGridRow.OnGotFocus 事件。
if (editingEventArgs != null) editingEventArgs.Handled = true;
success = true;
}
}
return success;
}
/// <summary>
/// 为指定的结点应用 <see cref="RowStyle"/> 样式。
///
/// 子类重写此方法用于应用自定义样式。
/// </summary>
/// <param name="treeNode">The node to be styled.</param>
private void ApplyNodeStyle(TreeGridRow treeNode)
{
var style = this.RowStyle;
if (style != null) treeNode.Style = style;
}
/// <summary>
/// 设置某行的“选中”状态
///
/// 维护两个底层属性：一个是选择项 List，一个是 row 的选择状态属性。
/// </summary>
/// <param name="row"></param>
/// <param name="isSelected">是“选中”状态还是“未选中”状态。</param>
internal void MarkSelected(TreeGridRow row, bool isSelected)
{
this.ModifyList(row.DataContext, isSelected);
this.ModifyRowProperty(row, isSelected);
}
/// <summary>
/// 在结点被收缩起来时，应该它的子结点的所有数据在_objectItems中对应的项都移除。
/// </summary>
/// <param name="treeNode"></param>
private void OnNodeCollapsed(TreeGridRow treeNode)
{
//处理 LazyLoading
//结点被折叠后事件。
//如果懒加载开启后，则在折叠时清空所有子结点。
//不处理根结点。
if (treeNode != this.RootNode)
{
//更新布局
var itemKey = GetId(treeNode.DataContext);
_renderExpansion.Remove(itemKey);
if (this.IsLazyLoading && this.ClearCollapsedNodes && treeNode.Items.Count > 0)
{
//deregisters listeners for all ancestors
if (this.ObserveChildItems)
{
_monitor.RemoveNodes(treeNode.Items);
}
treeNode.ItemsSource = null;
TreeGridHelper.CreateDummyItem(treeNode);
//TODO do we have collapsed event if all childs are being filtered?
//if yes, we need to set the dummy nodes visibility depending
//on the filtered childs (visible if at least 1 visible child)
}
}
}
/// <summary>
/// 设置某行的选择状态，并级联选择
/// </summary>
/// <param name="row"></param>
/// <param name="value"></param>
internal void CheckRowWithCascade(TreeGridRow row, bool value)
{
if (!this.IsCheckingEnabled) { return; }
var entity = row.DataContext;
this.CheckingModel.MarkSelected(row, value);
this.RasieCheckChanged(entity, value);
//CascadeParent 模式下，需要把所有父对象选中。
if (value && this.NeedCascade(CheckingCascadeMode.CascadeParent))
{
object parent = this.GetParentItem(entity);
while (parent != null)
{
var parentRow = this.FindRow(parent);
if (parentRow == null || parentRow.IsChecked) { break; }
this.CheckingModel.MarkSelected(parentRow, true);
this.RasieCheckChanged(parent, true);
parent = this.GetParentItem(parent);
}
}
//CascadeChildren 模式下，需要把所有子对象选中。
if (this.NeedCascade(CheckingCascadeMode.CascadeChildren))
{
this.CheckChildrenRecur(entity, value);
}
}
private void FindViewPort(TreeGridRow row)
{
var itemsControl = row.ParentItemsControl;
if (itemsControl != null)
{
var scrollViewer = MSInternal.GetScrollHost(itemsControl);
if (scrollViewer != null && scrollViewer.CanContentScroll)
{
var itemsHost = MSInternal.GetItemsHost(itemsControl);
if (itemsHost is VirtualizingPanel)
{
this._viewPort = scrollViewer.Template.FindName(PART_ScrollContentPresenter, scrollViewer) as FrameworkElement;
if (this._viewPort == null)
{
this._viewPort = scrollViewer;
}
}
}
}
}
/// <summary>
/// 开始编辑某行。
/// </summary>
/// <param name="row"></param>
/// <param name="editingEventArgs">引发编辑的事件参数。</param>
/// <param name="focusCell">编辑后，应该首先进入编辑状态的单元格。</param>
internal bool TryEditRow(TreeGridRow row, RoutedEventArgs editingEventArgs, TreeGridCell focusCell)
{
var success = false;
if (!this.IsReadOnly && this.EditingMode == TreeGridEditingMode.Row)
{
var item = row.DataContext;
var selectedItems = this.SelectionModel.InnerItems;
//由于点击任何一行的该列都会发生此事件，所以需要检测如果当前只选择了一列
if (selectedItems.Count == 1 && item == selectedItems[0])
{
//先退出之前行的编辑状态。
if (this._editingItem != item)
{
this.ExitRowEditing();
this._editingItem = item;
}
//focused 表示是否已经有单元格设置了焦点。
bool focused = focusCell != null;
var mouseArgs = editingEventArgs as MouseButtonEventArgs;
//设置所有单元格的编辑状态，及焦点。
var cells = row.TraverseCells();
foreach (var cell in cells)
{
//设置单元格的编辑状态
if (!cell.IsEditing && cell.Column.CanEdit(this._editingItem))
{
cell.SetIsEditingField(true);
}
//如果成功设置单元格的编辑状态，而且还没有设置单元格焦点，
//那么就通过鼠标的坐标来判断是否需要设置当前单元格的焦点。
if (!focused && mouseArgs != null && cell.IsEditing && cell.VisibleOnVirtualizing)
{
var position = mouseArgs.GetPosition(cell);
var cellPosition = new Rect(cell.RenderSize);
if (cellPosition.Contains(position))
{
cell.FocusOnEditing(editingEventArgs);
focused = true;
}
}
}
if (focusCell != null)
{
focusCell.FocusOnEditing(editingEventArgs);
}
//标记事件已经处理，防止事件继续冒泡导致引发 TreeGridRow.OnGotFocus 事件。
if (editingEventArgs != null)
{
editingEventArgs.Handled = true;
}
success = true;
}
}
return(success);
}
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
var rowPresenter = ItemsControl.ItemsControlFromItemContainer(this) as TreeGridCellsPresenter;
if (rowPresenter != null) { this._row = rowPresenter.Row; }
}
internal static void CreateDummyItem(TreeGridRow treeNode)
{
////clear items and insert dummy
//treeNode.Items.Clear();
//treeNode.Items.Add(this.CreateDummyItem());
}
/// <summary>
/// Removes listener for an item that is represented
/// by a given <paramref name="node"/> from the cache, and also
/// processes all the node's descendants recursively.
/// </summary>
/// <param name="node">The node to be removed.</param>
public void UnregisterListeners(TreeGridRow node)
{
lock (this)
{
//try to get the represented item
object item = node.DataContext;
if (item == null) return;
//get the item's observed child collection and
//deregister it
var itemKey = tree.GetId(item);
RemoveCollectionFromCache(itemKey);
foreach (TreeGridRow childNode in node.Items)
{
//recursively deregister descendants by
//removing all child nodes
UnregisterListeners(childNode);
}
}
}
private void OnNodeExpanded(TreeGridRow treeNode)
{
//处理 LazyLoading
//结点被展开后事件
//完成懒加载时的结点创建工作，并设置各结点的 Filter 属性。
object item = treeNode.DataContext;
if (item != null)
{
//布局
var itemKey = GetId(item);
_renderExpansion.Add(itemKey);
var nodeItems = treeNode.Items;
//懒加载状态下，创建结点。
if (this.IsLazyLoading)
{
TreeGridHelper.ClearDummyChildNode(treeNode);
if (nodeItems.Count == 0)
{
var childItems = this.GetChildItems(item);
treeNode.ItemsSource = childItems;
//刷新以排序
if (nodeItems.NeedsRefresh) { nodeItems.Refresh(); }
}
}
if (nodeItems.Count == 0)
{
//如果结点没有数据，则不需要展开它。
treeNode.IsExpanded = false;
_renderExpansion.Remove(itemKey);
}
}
}
/// <summary>
/// Copy from TreeView class.
/// </summary>
/// <param name="data"></param>
/// <param name="newRow"></param>
/// <param name="selected"></param>
internal void ChangeSelection(object data, TreeGridRow newRow, bool selected)
{
//同步本对象的 SelectedItem 属性。
if (selected)
{
this.SelectedItem = data;
}
else
{
if (this.SelectedItem == data)
{
this.SelectedItem = null;
}
}
}
internal static bool IsDummyItem(TreeGridRow item)
{
return(false);
//return TreeGrid.GetEntity(item) == null;
}
/*********************** 代码块解释 *********************************
*
* 树结点的选择事件处理
*
* 基类的此方法以一种防止 TreeView 重入的方式来同步 this.SelectedItem 到 TreeView.SelecteItem 上。
* 并在最后调用 this.OnSelectedItemChanged 方法，以抛出路由事件。
*
* 注意这三个方法的顺序：
* OnTreeViewSelectedItemChanged
* OnSelectedItemPropertyChanged
* RaiseSelectedItemChanged
*
**********************************************************************/
/// <summary>
/// Copy from TreeView class.
/// </summary>
/// <param name="collapsed"></param>
internal void HandleSelectionOnCollapsed(TreeGridRow collapsed)
{
using (this.SelectionProcess.TryEnterProcess(TGSelectionProcess.Row_Collapsed))
{
if (this.SelectionProcess.Success)
{
//目前只支持在单选的时候，提供此功能。
if (this.SelectParentOnCollapsed && this.SelectionModel.InnerItems.Count == 1)
{
var selectedRow = this.SelectedRow;
if (selectedRow != null && selectedRow != collapsed)
{
//检查 collapsed 是否为 selectedRow 的父行。
bool selectionInCollapsed = false;
for (var parent = selectedRow; parent != null; parent = parent.ParentRow)
{
//找到 collasped 对象
if (parent == collapsed)
{
selectionInCollapsed = true;
break;
}
}
if (selectionInCollapsed)
{
this.ChangeSelection(collapsed.DataContext, collapsed, true);
if (selectedRow.IsKeyboardFocusWithin)
{
selectedRow.Focus();
return;
}
}
}
}
}
}
}
internal static void CreateDummyItem(TreeGridRow treeNode)
{
////clear items and insert dummy
//treeNode.Items.Clear();
//treeNode.Items.Add(this.CreateDummyItem());
}
/// <summary>
/// 设置行对应的选中状态属性
/// </summary>
/// <param name="row"></param>
/// <param name="isSelected"></param>
internal void ModifyRowProperty(TreeGridRow row, bool isSelected)
{
if (this.IsChecking)
{
row.SetIsCheckedField(isSelected);
}
else
{
//然后，需要设置 TreeListItem.IsSelected 属性。
//否则，会造成内部使用的 TreeView 的 SelectedItem 属性不变，但是高亮的状态已经被清除，
//这时用户再次点击该行时，TreeView 的 SelectedItemChanged 事件不会发生，
//也就不会发生整个 MTTG 的 SelectedItem 处理流程，造成无法选中该行。
//具体情况见 bug：http://ipm.grandsoft.com.cn/issues/247260
row.SetIsSelectedField(isSelected);
}
}
/// <summary>
/// Copies the <see cref="SortDescription"/> elements of
/// the <see cref="NodeSortDescriptions"/> collection to
/// a currently processed tree node. This method is being
/// invoked during the initialization of a given node, and
/// if the <see cref="NodeSortDescriptions"/> property
/// is changed at runtime.<br/>
/// If the <see cref="ItemCollection.SortDescriptions"/>
/// collection of the submitted <paramref name="node"/> is
/// not empty, it will be cleared.<br/>
/// This method is always being invoked, even if the
/// <see cref="NodeSortDescriptions"/> dependency property
/// is null. If you want to apply a custom sorting mechanism,
/// simply override this method.
/// </summary>
/// <param name="node">The currently processed node, if any.
/// This parameter is null if sort parameters should be set
/// on the tree's <see cref="ItemsControl.Items"/>
/// collection itself.
/// </param>
private void ApplySorting(TreeGridRow node)
{
//check whether we're sorting on node or tree level
var items = node == null ? this.Items : node.Items;
using (items.DeferRefresh())
{
//clear existing sort directions, if there are any
items.SortDescriptions.Clear();
//copy new sort directions
if (this.NodeSortDescriptions != null)
{
foreach (var sd in this.NodeSortDescriptions)
{
items.SortDescriptions.Add(sd);
}
}
}
}
private void RefreshRowNo(TreeGridRow row)
{
//目前为了简单起见，只支持表格模式下有行号。（因为在树型模式下，行号应该使用递归遍历后计算生成。）
if (this.OnlyGridMode)
{
//不能直接使用 DataItemsSource，这是因为可能界面会对集合进行排序。
//var item = GetEntity(row);
//var rowNo = this.DataItemsSource.IndexOf(item) + 1;
//row.RowNo = rowNo;
row.RowNo = this.ItemContainerGenerator.IndexFromContainer(row) + 1;
}
}
/// <summary>
/// 开始编辑某行。
/// </summary>
/// <param name="row"></param>
/// <param name="focusCell">编辑后，应该首先进入编辑状态的单元格。</param>
public bool TryEditRow(TreeGridRow row, TreeGridCell focusCell)
{
return this.TryEditRow(row, null, focusCell);
}