Can't render the treenode of Table when lazily loading it's datasource.

Can’t render the treenode of Table when lazily loading it’s datasource.

If the datasource is null or empty, and fetch data in the override method OnInitializedAsync. Then the table can’t render the treenode.

For the example https://ant-design-blazor.gitee.io/zh-CN/components/table#components-table-demo-tree-data, if the code like this

...
<Table DataSource="data" TreeChildren="item=>item.Children">
    <Selection CheckStrictly />
    <Column @bind-Field="@context.Name" />
    <Column @bind-Field="@context.Age" Width="12%"/>
    <Column @bind-Field="@context.Address" Width="30%"/>
</Table>
...
@code{
  Data[] data = null;
  protected override async Task OnInitializedAsync()
  {
    await Task.Delay(1);
    data = ....; 
    // or data = await something();
    await base.OnInitializedAsync();
  }
}

I think this code https://github.com/ant-design-blazor/ant-design-blazor/blob/master/components/table/Table.razor.cs#L198 should be:

            if (TreeChildren != null)
            {
                _treeMode = true;
            }

When I set TreeChildren delegate it should be tree table, instead of whether the children have data.

[kateusz]

I’ve discovered similar issue, all repro steps are done in OnInitializedAsync:

1. Add rows without children to table
2. Make async operation
3. Add children to existing rows Result: The table shows rows without tree nodes

The view:

<Table DataSource="Nodes" TreeChildren="item=>item.Children">
    <Selection Disabled />
    <Column @bind-Field="@context.Name" />
    <ActionColumn Title="Action">
    </ActionColumn>
</Table>

Code behind:

public class Node
    {
        public Node(string name)
        {
            Name = name;
            Children = new List<Node>();
        }

        public string Name { get; set; }
        public List<Node> Children { get; set; }
    }

    public partial class TableTest
    {
        private List<Node> Nodes { get; set; } = new List<Node>();

        protected override async Task OnInitializedAsync()
        {
            var nodeNames = new List<string> { "First", "Second" };

            foreach (var nodeName in nodeNames) 
                Nodes.Add(new Node(nodeName));

            // represents some async operation, eg. get data from API
            await Task.Delay(100);

            // nothing happened after this line
            foreach (var node in Nodes) 
                node.Children.Add(new Node("test"));
        }
    }

[ElderJames]

目前不初始化的话，是识别不了是children。需要指定children的话请另外创建一个issue。