You do not need to loop all the grid rows, you just need the checked. Here is how to get checked rows:
this.grid0.data.filter(i => i.checked)
You have now array of only needed objects and you can use them to send data to your custom server method. Let's say for example you have the following custom custom server method:
[HttpPost]
public IActionResult DoSomething([FromBody] int[] selectedIds)
{
return new NoContentResult();
}
Now to pass an array with Ids from checked items you need to following instead [1,2,3]:
this.grid0.data.filter(i => i.checked).map(i => i.Id)

