Declined
Last Updated:
07 Jan 2026 11:41
by ADMIN
Hani
Created on:
04 May 2021 14:03
Category:
TreeList
Type:
Bug Report
Collapsing an item collapses all items and you can't expand them anymore when binding to IEnumerable<T> (works with List<T>)
The code below compiles and doesn't give any browser errors when run, but when you collapse a row, all data is collapsed and you can't expand it again.
If you change the line that generates the data to use a List instead of IEnumerable it will work as expected.
REPRODUCIBLE
<TelerikTreeList Data=Data
IdField="@nameof(Record.Id)"
ParentIdField="@nameof(Record.ParentId)"
Height="100%">
<TreeListColumns>
<TreeListCheckboxColumn CheckBoxOnlySelection="true" />
<TreeListColumn Field="@nameof(Record.Text)" Title="" Expandable="true" />
<TreeListColumn Field="@nameof(Record.Id)" Title="ID" />
<TreeListColumn Field="@nameof(Record.ParentId)" Title="PARENT" />
</TreeListColumns>
</TelerikTreeList>
@code {
protected IEnumerable<Record> Data = new List<Record>();
protected override void OnInitialized()
{
Data = Enumerable.Range(1, 10).Select(i => new Record(i));
}
public class Record
{
public Record(int i)
{
Id = i;
if (i % 5 == 1)
ParentId = null;
else
ParentId = (i - ((i - 1) % 5));
Text = "Item " + i;
}
public long Id { get; set; }
public long? ParentId { get; set; }
public string Text { get; set; }
}
} WORKAROUND
<TelerikTreeList Data=Data
IdField="@nameof(Record.Id)"
ParentIdField="@nameof(Record.ParentId)"
Height="100%">
<TreeListColumns>
<TreeListCheckboxColumn CheckBoxOnlySelection="true" />
<TreeListColumn Field="@nameof(Record.Text)" Title="" Expandable="true" />
<TreeListColumn Field="@nameof(Record.Id)" Title="ID" />
<TreeListColumn Field="@nameof(Record.ParentId)" Title="PARENT" />
</TreeListColumns>
</TelerikTreeList>
@code {
protected List<Record> Data = new List<Record>();
protected override void OnInitialized()
{
Data = Enumerable.Range(1, 10).Select(i => new Record(i)).ToList();
}
public class Record
{
public Record(int i)
{
Id = i;
if (i % 5 == 1)
ParentId = null;
else
ParentId = (i - ((i - 1) % 5));
Text = "Item " + i;
}
public long Id { get; set; }
public long? ParentId { get; set; }
public string Text { get; set; }
}
}
1 comment
ADMIN
Petar Mladenov
Posted on:
07 Jan 2026 11:41