如何在blazor中通过外部代码设置选择框值？

<select id="mySelect"></select>

@using Microsoft.JSInterop;

@code {
    [Inject]
    public IJSRuntime JSRuntime { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            await JSRuntime.InvokeVoidAsync("setSelectValue", "mySelect", "optionValue");
        }
    }
}

function setSelectValue(selectId, value) {
    var select = document.getElementById(selectId);
    select.value = value;
}

<script src="custom.js"></script>