/// <summary>
/// 多选模式时级联调整选择状态
/// </summary>
/// <param name="p_item"></param>
internal void ToggleSelectedCascade(TvItem p_item)
{
_selectedRows.CollectionChanged -= OnSelectedItemsChanged;
var adds = new List <object>();
var removes = new List <object>();
try
{
if (!p_item.IsSelected.HasValue || p_item.IsSelected.Value)
{
UnselectCascade(p_item, removes);
}
else
{
SelectCascade(p_item, adds);
}
}
finally
{
_selectedRows.CollectionChanged += OnSelectedItemsChanged;
}
if (SelectionChanged != null && (adds.Count > 0 || removes.Count > 0))
{
SelectionChanged(this, new SelectionChangedEventArgs(removes, adds));
}
}
/// <summary>
/// 单选模式点击时切换选择
/// </summary>
/// <param name="p_item"></param>
internal void OnToggleSelected(TvItem p_item)
{
List <object> removes = new List <object>();
try
{
_selectedRows.CollectionChanged -= OnSelectedItemsChanged;
if (_selectedRows.Count > 0)
{
var row = _selectedRows[0];
row.IsSelected = false;
removes.Add(row.Data);
_selectedRows.Clear();
}
_selectedRows.Add(p_item);
p_item.IsSelected = true;
HasSelected = true;
}
finally
{
_selectedRows.CollectionChanged += OnSelectedItemsChanged;
}
SelectionChanged?.Invoke(this, new SelectionChangedEventArgs(removes, new List <object> {
p_item.Data
}));
}
void UpdateParentUnselect(TvItem p_item, List <object> p_data)
{
bool isAll = true;
foreach (var item in p_item.Children)
{
if (!item.IsSelected.HasValue || item.IsSelected.Value)
{
isAll = false;
break;
}
}
if (isAll)
{
// 子节点全未选
if (p_item.IsSelected.HasValue && p_item.IsSelected.Value)
{
_selectedRows.Remove(p_item);
p_data.Add(p_item.Data);
}
p_item.IsSelected = false;
}
else
{
// 部分选，未知状态
p_item.IsSelected = null;
}
p_item = p_item.Parent;
while (p_item != null)
{
UpdateParentUnselect(p_item, p_data);
p_item = p_item.Parent;
}
}
public TvItem(Tv p_tv, object p_data, TvItem p_parent)
{
_owner = p_tv;
Data = p_data;
Parent = p_parent;
Depth = (p_parent == null) ? 0 : p_parent.Depth + 1;
Children = new List <TvItem>();
}
/// <summary>
/// 级联选择
/// </summary>
/// <param name="p_item"></param>
/// <param name="p_data"></param>
void SelectCascade(TvItem p_item, List <object> p_data)
{
p_item.IsSelected = true;
_selectedRows.Add(p_item);
p_data.Add(p_item.Data);
if (p_item.Parent != null)
{
UpdateParentSelect(p_item.Parent, p_data);
}
UpdateChildSelect(p_item, p_data);
}
/// <summary>
/// 展开从根节点到当前节点的所有节点
/// </summary>
public void ExpandAll()
{
TvItem parent = Parent;
while (parent != null)
{
parent.IsExpanded = true;
parent = parent.Parent;
}
if (Children.Count > 0 && !IsExpanded)
{
IsExpanded = true;
}
}
void UnselectCascade(TvItem p_item, List <object> p_data)
{
if (p_item.IsSelected.HasValue && p_item.IsSelected.Value)
{
_selectedRows.Remove(p_item);
p_data.Add(p_item.Data);
}
p_item.IsSelected = false;
if (p_item.Parent != null)
{
UpdateParentUnselect(p_item.Parent, p_data);
}
UpdateChildUnselect(p_item, p_data);
}
void UpdateChildUnselect(TvItem p_item, List <object> p_data)
{
if (p_item.Children.Count == 0)
{
return;
}
foreach (var item in p_item.Children)
{
if (item.IsSelected.HasValue && item.IsSelected.Value)
{
_selectedRows.Remove(p_item);
p_data.Add(p_item.Data);
}
item.IsSelected = false;
UpdateChildUnselect(item, p_data);
}
}
void UpdateChildSelect(TvItem p_item, List <object> p_data)
{
if (p_item.Children.Count == 0)
{
return;
}
foreach (var item in p_item.Children)
{
if (!item.IsSelected.HasValue || !item.IsSelected.Value)
{
item.IsSelected = true;
_selectedRows.Add(p_item);
p_data.Add(p_item.Data);
}
UpdateChildSelect(item, p_data);
}
}
/// <summary>
/// 触发加载子节点事件
/// </summary>
/// <param name="p_item"></param>
/// <returns></returns>
internal async Task OnLoadingChild(TvItem p_item)
{
if (LoadingChild == null)
{
return;
}
var args = new LoadingChildArgs(p_item);
LoadingChild(this, args);
await args.EnsureAllCompleted();
if (args.Children != null)
{
foreach (var item in args.Children)
{
TvItem ti = new TvItem(this, item, p_item);
ti.ExpandedState = TvItemExpandedState.NotExpanded;
p_item.Children.Add(ti);
}
RootItems.Invalidate();
}
p_item.HasLoadedChildren = true;
}
public LoadingChildArgs(TvItem p_item)
{
CurrentItem = p_item;
}
void OnKeyDown(object sender, KeyRoutedEventArgs e)
{
if (SelectionMode == SelectionMode.Multiple || RootItems.Count == 0)
{
return;
}
TvItem row;
switch (e.Key)
{
case VirtualKey.Down:
row = SelectedRows.LastOrDefault();
if (row == null)
{
OnToggleSelected(RootItems[0]);
}
else
{
using (var ls = RootItems.GetExpandedItems().GetEnumerator())
{
while (ls.MoveNext())
{
if (ls.Current == row)
{
if (ls.MoveNext())
{
OnToggleSelected(ls.Current);
}
else
{
OnToggleSelected(RootItems[0]);
}
break;
}
}
}
}
e.Handled = true;
return;
case VirtualKey.Up:
row = SelectedRows.LastOrDefault();
if (row == null)
{
OnToggleSelected(RootItems[0]);
}
else
{
using (var ls = RootItems.GetExpandedItems().GetEnumerator())
{
if (ls.MoveNext())
{
if (ls.Current == row)
{
SelectedItem = null;
}
else
{
while (true)
{
TvItem lastRow = ls.Current;
if (ls.MoveNext())
{
if (ls.Current == row)
{
OnToggleSelected(lastRow);
break;
}
}
}
}
}
}
}
e.Handled = true;
return;
case VirtualKey.Enter:
row = SelectedRows.LastOrDefault();
if (row != null)
{
row.OnClick();
}
return;
default:
return;
}
}