DataGrid/Columns - Display dynamic object arrays

Radzen.Blazor Components
1

Hi - we're trying to implement the DataGrid and DataGridColumns to dynamically display results returned from a SQL query. Since a query could be against any of a large number of tables (no model classes), we generically store the column definitions in their own list, and the table of results as a list of object arrays.

Here's a snippet:

<RadzenDataGrid AllowFiltering="true" FilterMode="FilterMode.Advanced" AllowPaging="true" PageSize="25" AllowSorting="true" Data="@this.fullQueryResults" TItem="object[]" IsLoading="@this.runningQuery" Count="@this.fullQueryResults.Count">
	<Columns>
		@for (int i = 0; i < this.dbColumns.Count; i++)
		{
			<RadzenDataGridColumn TItem="object[]" Title="@this.dbColumns[i].Name" Type="@DatabaseHelper.GetClrType(this.dbColumns[i].DataType)">
				<Template>
					@context[i].ToString()
				</Template>
			</RadzenDataGridColumn>
		}
	</Columns>
</RadzenDataGrid>

But it's running into a runtime error when we try to display the results:

Error: System.NullReferenceException: Object reference not set to an instance of an object.
at Radzen.PropertyAccess.IsNumeric(Type source)
at Radzen.Blazor.RadzenDataGrid`1.BuildRenderTree(RenderTreeBuilder __builder)

My assumption is that the RadzenDataGridColumn element is missing the 'Property' property. However, I'm not sure what the solution would be to work around this, since we don't have any specific property names we're accessing, rather the ToString() representation of the object itself.

2

Is there any chance that DatabaseHelper.GetClrType returns null in some cases? This is the only reason why PropertyAccess.IsNumeric could throw a NullReferenceException. Can be verified by not setting the Type property or the column.

3

Nope, that method would throw an exception instead of return null. And, I just tried removing the 'Type' specification on the column but I'm still seeing the same exception as above.

4

I saw where the problem is. Try setting some arbitrary Property value and it should probably work. We will handle this case with the next Radzen release though.