/// <summary>
/// 逐级找出子节点。
/// </summary>
/// <param name="nodes">当前的节点集合。</param>
/// <param name="parents">父节点ID集合。</param>
/// <param name="factory">生成节点的函数。</param>
/// <param name="index">控制从后向前推进的索引值。</param>
public static void Expand <TSource, TValue>(this List <TSource> nodes, List <TValue> parents, Func <TValue, IEnumerable <TSource> > factory, int index) where TSource : ITreeNode <TSource>
{
TreeNodeExpandScope control = null;
if (parents.Count == 0 || index < 0)
{
return;
}
if (TreeNodeExpandScope.Current == null)
{
control = new TreeNodeExpandScope();
}
try
{
foreach (var node in nodes)
{
if (parents[index].ToStringSafely() == node.Id)
{
node.Children = factory(node.Id.To <TValue>()).ToList();
node.IsLoaded = true;
Expand(node.Children, parents, factory, index - 1);
}
}
}
finally
{
if (control != null)
{
control.Dispose();
}
}
}
/// <summary>
/// 异步的，逐级找出子节点。
/// </summary>
/// <param name="nodes">当前的节点集合。</param>
/// <param name="parents">父节点ID集合。</param>
/// <param name="nodesCreator">生成节点的函数。</param>
/// <param name="index">控制从后向前推进的索引值。</param>
public static async Task ExpandAsync <TSource, TValue>(this List <TSource> nodes, List <TValue> parents, Func <TValue, Task <IEnumerable <TSource> > > nodesCreator, int index)
where TSource : ITreeNode <TSource>
where TValue : IEquatable <TValue>
{
TreeNodeExpandScope control = null;
if (parents.Count == 0 || index < 0)
{
return;
}
if (TreeNodeExpandScope.Current == null)
{
control = new TreeNodeExpandScope();
}
try
{
foreach (var node in nodes)
{
if (parents[index].Equals((TValue)node.Id))
{
node.Children = (await nodesCreator((TValue)node.Id)).ToList();
node.IsLoaded = true;
await ExpandAsync(node.Children, parents, nodesCreator, index - 1);
}
}
}
finally
{
if (control != null)
{
control.Dispose();
}
}
}
