blazor variable argument passing to onclick function [duplicate]

I want to pass the int i into the button onclick function for each list item. I expected the "clickItem" function will receive 0..2 for correspondig list item. But it come out that it always receive 3 as argument. It seems that the variable i in the clickItem(i) is not evaluated at the time of render of the for loop. I have tried changing it to "clickItem(@i)" but it is still the same. What should I do? (I am using blazor server side, .net core 3 preview 5)

        @for (int i = 0; i < 3; i++)
        {
            <li> item @i <button onclick=@(() => clickItem(i))>Click</button> </li>
        }

Solution 1:

This is a classic, but slightly new in the context of Blazor.

You need to make a copy because otherwise the lambda 'captures' the loop variable. Capturing the copy is OK.

@for (int i = 0; i < 3; i++)
{
    int copy = i;
    <li> item @i <button onclick=@(() => clickItem(copy))>Click</button> </li>
}

Note that this is an issue with for() loops but not with foreach().