GridForeignColumn not working

[Andy Richard]

This worked on a different project and I have followed everything to the letter but no luck on my current project. Both task and risks objects are populated correctly when I inspect the values in code. But I get the browser error below when I run the code. If I leave out the GridForeignColumn from the code the grid displays correctly. Is there anything obvious I'm doing wrong? I'm using version 19.4.0.41


This is my code:

<SfTreeGrid @ref="treeGrid" ID="grid" DataSource="@tasks" IdMapping="Id" ParentIdMapping="ParentId" TreeColumnIndex="1" Toolbar="@(new List<string>() { "Add", "Edit", "Delete", "Save", "Cancel" })" AllowExcelExport="true" AllowPdfExport="true" AllowReordering="true" AllowFiltering="true" AllowMultiSorting="true" AllowPaging="false" AllowResizing="true" AllowRowDragAndDrop="true" AllowSelection="true" AllowSorting="true" AllowTextWrap="true" AutoCheckHierarchy="true" EnableCollapseAll="true">

<TreeGridEditSettings AllowAdding="true" AllowDeleting="true" AllowEditing="true" AllowEditOnDblClick="true" NewRowPosition="Syncfusion.Blazor.TreeGrid.RowPosition.Below" />

<Syncfusion.Blazor.TreeGrid.TreeGridEvents TValue="Models::Task" RowDataBound="OnRowDataBound" OnActionBegin="ActionBegin" OnActionComplete="ActionComplete" RowDropped="RowDropped" Expanded="Expanded" />

<Syncfusion.Blazor.TreeGrid.TreeGridSelectionSettings Type="Syncfusion.Blazor.Grids.SelectionType.Multiple" />

<TreeGridColumns>

<TreeGridColumn Field=@nameof(Models::Task.Id) HeaderText="Id" IsIdentity="true" IsPrimaryKey="true" Visible="false" />

<TreeGridColumn Field=@nameof(Models::Task.Name) HeaderText="Name" />

<TreeGridColumn Field=@nameof(Models::Task.StartDate) HeaderText="Start Date" />

<TreeGridColumn Field=@nameof(Models::Task.EndDate) HeaderText="End Date" />

<GridForeignColumn Field=@nameof(Models::Task.RiskId) ForeignKeyField="Id" ForeignKeyValue="Name" ForeignDataSource="@risks" HeaderText="Risk"></GridForeignColumn>

</TreeGridColumns>

</SfTreeGrid>

Models:
    public partial class Risk
    {
        public Risk()
        {
            Tasks = new HashSet();
        }
        public int Id { get; set; }
        public string Name { get; set; }
        public string Code { get; set; }
        public virtual ICollection Tasks { get; set; }
    }

    public partial class Task

    {
        public Task()
        {
        }

        public int Id { get; set; }
        public int? ParentId { get; set; }
        public string Name { get; set; }
        public DateTime? StartDate { get; set; }
        public DateTime? EndDate { get; set; }
        public int RiskId { get; set; }

        public virtual EstimateVersion EstimateVersion { get; set; }
        public virtual MeasurementUnit MeasurementUnit { get; set; }
        public virtual Task Parent { get; set; }
        public virtual Risk Risk { get; set; }
    }


Error:

Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
   at Syncfusion.Blazor.Grids.GridForeignColumn`1[[Blahblahblah.Models.Risk, SoftwareTools.Tarvio.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].OnParametersSet()
   at Microsoft.AspNetCore.Components.ComponentBase.CallOnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.SetParametersAsync(ParameterView parameters)
   at Syncfusion.Blazor.SfDataBoundComponent.SetParametersAsync(ParameterView parameters)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.SupplyCombinedParameters(ParameterView directAndCascadingParameters)

[Pon Selva Jeganathan]

Hi Andy Richard, 

  

Thanks for contacting syncfusion forum. 

 

Query: GridForeignColumn not working

  

Currently, We don’t have the Foreign Key support in TreeGrid(i.e. the Foreignkey column dataSource which is separate from the TreeGrid dataSource). But we can use self-referential data support which has the foreign key relationship within them. 

  

Refer the below help links,  

Documentation – https://blazor.syncfusion.com/documentation/treegrid/data-binding/#self-referential-data-bindingflat-data  

Demo – https://blazor.syncfusion.com/demos/tree-grid/default-functionalities?theme=bootstrap4  

  

Kindly get back to us for further assistance.  

  

Regards, 

Pon selva