/// <summary>
/// 展开某个节点
/// </summary>
/// <param name="treeItem"></param>
public async Task ExpandAsync(TreeItemBase treeItem, bool autoRefresh = true)
{
if (treeItem.Expanded)
{
return;
}
treeItem.Expanded = true;
if (LoadFullTree != null && LoadFullTree.Value)
{
var children = FindChildren(treeItem);
await ExpandAsync(children, false);
if (autoRefresh)
{
Refresh();
}
return;
}
if (!string.IsNullOrWhiteSpace(Url))
{
EnsureUrl();
var responseObj = (IEnumerable)await httpClient.GetFromJsonAsync(Url + treeItem.Id, typeof(List <>).MakeGenericType(ItemType));
var newTreeNodes = responseObj.Cast <TreeItemBase>().ToArray();
DataSource.RemoveAll(x => newTreeNodes.Any(y => y.Id == x.Id));
DataSource.AddRange(newTreeNodes);
var rootNodes = FindChildren(new TreeItemModel()
{
Children = items
});
Initilize(rootNodes, null);
await AutoExpandAllAsync();
}
Refresh();
}
/// <summary>
/// 展开某个节点，如果这个节点当前没有子节点，则动态加载子节点
/// </summary>
/// <param name="item"></param>
/// <param name="forceLoad">是否强制加载新数据</param>
public async Task ExpandAsync(TreeItemBase item, bool forceLoad = false)
{
if (string.IsNullOrWhiteSpace(Url))
{
ExceptionHelper.Throw(ExceptionHelper.ExpandOnlyHasUrl, "展开某个节点只支持异步加载");
}
ResetSelectAllStatus();
item.Expanded = true;
var finalChildren = GetAllChildren(item);
if (forceLoad || !finalChildren.Any())
{
if (!forceLoad)
{
item.HasChildren = true;
}
if (finalChildren.Count != rows.RemoveAll(finalChildren.Contains))
{
ExceptionHelper.Throw(ExceptionHelper.ClearChildFailure, "清空子节点失败");
}
DataSource = rows;
await LoadChildrenAsync(item, AutoExpandAll);
Refresh();
return;
}
LocalExpand(item, finalChildren);
Refresh();
}
private async Task LoadChildrenAsync(TreeItemBase row, bool autoExpand)
{
row.Expanded = true;
row.IsLoading = true;
Refresh();
var newDataSource = await FetchChildrenAsync(row);
row.IsLoading = false;
var enumerbale = DataSource as IEnumerable;
var startIndex = 0;
foreach (var item in enumerbale)
{
if (item == row)
{
break;
}
startIndex++;
}
var oldDataSource = enumerbale.Cast <object>().ToList();
oldDataSource.InsertRange(startIndex + 1, (newDataSource as IEnumerable).Cast <object>());
DataSource = oldDataSource;
await InitlizeDataSourceAsync(row.Level.Value + 1, "up", autoExpand);
if (DataSourceChanged.HasDelegate)
{
await DataSourceChanged.InvokeAsync(DataSource);
}
SyncFieldValue();
}
private List<TreeItemBase> FindChildren(TreeItemBase treeItem)
{
switch (DataFormat)
{
case DataFormat.List:
return items.Where(x => x.ParentId == treeItem.Id).ToList();
case DataFormat.Children:
return treeItem.Children ?? new List<TreeItemBase>();
}
return new List<TreeItemBase>();
}
private async Task ToggleAsync(TreeItemBase item)
{
if (item.Expanded)
{
item.Expanded = false;
Refresh();
}
else
{
await ExpandAsync(item);
}
}
private List <TreeItemBase> FindChildren(TreeItemBase child)
{
var results = new List <TreeItemBase>();
var treeItems = rows.Cast <TreeItemBase>().Where(x => x.ParentId == child.Id).ToArray();
foreach (var childTreeItem in treeItems)
{
results.Add(childTreeItem);
results.AddRange(FindChildren(childTreeItem));
}
return(results);
}
private void Initilize(List <TreeItemBase> nodes, TreeItemBase parentNode)
{
foreach (var node in nodes)
{
node.Level = (parentNode?.Level ?? -1) + 1;
node.TextPaths = parentNode?.TextPaths == null ? new Dictionary <int, string>() : new Dictionary <int, string>(parentNode.TextPaths);
if (!node.TextPaths.ContainsKey(node.Id))
{
node.TextPaths.Add(node.Id, node.Text);
}
Initilize(FindChildren(node), node);
}
}
private List <TreeItemBase> GetAllChildren(TreeItemBase treeRow)
{
var treeRows = rows.Cast <TreeItemBase>().ToArray();
var children = treeRows.Where(x => x.ParentId == treeRow.Id).ToList();
var finalChildren = children.ToList();
foreach (var item in children)
{
finalChildren.AddRange(FindChildren(item));
}
return(finalChildren);
}
private async Task ForceExpandAsync(TreeItemBase item)
{
if (string.IsNullOrWhiteSpace(Url))
{
ExceptionHelper.Throw(ExceptionHelper.ExpandOnlyHasUrl, "展开某个节点只支持异步加载");
}
item.Expanded = true;
var finalChildren = GetAllChildren(item);
item.HasChildren = true;
rows.RemoveAll(finalChildren.Contains);
await LoadChildrenAsync(item, AutoExpandAll);
Refresh();
}
private async Task SelectNodeAsync(TreeItemBase treeNode)
{
selectedNodes.Add(treeNode);
if (SelectedNodesChanged.HasDelegate)
{
_ = SelectedNodesChanged.InvokeAsync(selectedNodes);
}
if (Select != null)
{
await Select.OnInternalSelectAsync(new SelectResultModel <int?>()
{
Text = treeNode.TextPath,
Key = treeNode.Id
});
}
}
private async Task <IEnumerable> FetchChildrenAsync(TreeItemBase treeRow)
{
treeRow.Direction = "right";
if (!Url.EndsWith("/"))
{
Url += "/";
}
var newDataSource = (IEnumerable)await httpClient.GetFromJsonAsync(Url + treeRow.Id, typeof(List <>).MakeGenericType(DataType));
if (!newDataSource.Cast <object>().Any())
{
treeRow.HasChildren = false;
}
return(newDataSource);
}
private void CalculateLevel(List <TreeItemBase> treeItems, TreeItemBase parentNode, TreeItemBase[] allTreeItems)
{
foreach (var treeRow in treeItems)
{
if (treeRow.Level != null)
{
return;
}
treeRow.Level = (parentNode?.Level ?? -1) + 1;
treeRow.TextPaths = parentNode?.TextPaths == null ? new Dictionary <int, string>() : new Dictionary <int, string>(parentNode.TextPaths);
if (!treeRow.TextPaths.ContainsKey(treeRow.Id))
{
treeRow.TextPaths.Add(treeRow.Id, treeRow.Text);
}
var children = allTreeItems.Where(x => x.ParentId == treeRow.Id).ToList();
CalculateLevel(children, treeRow, allTreeItems);
}
}
private void LocalExpand(TreeItemBase treeRow, List <TreeItemBase> finalChildren)
{
hiddenRows.RemoveAll(finalChildren.Contains);
treeRow.Direction = "right";
treeRow.Expanded = true;
}
public async Task RefreshNodeAsync(TreeItemBase item)
{
await ExpandAsync(item, true);
}