Blazor server | functions happens twice

Question

User2110873642 posted

the following code results the console to output "tested" twice. the function runs 2 times. this is undesired behaviour for me.

why does this happen? and how can i avoid it?

@page "/Homepage"
<h3>Homepage</h3>


<div class="@test()"></div>

@code {
    public string test()
    {
        Console.WriteLine("tested");
        return "";
    }
}

Answer 1

User1535942433 posted

Hi fazioliamboina,

Accroding to your description and codes,as far as I think,it use  pre-rendering. Go to _Host.cshtml and  change render-model="ServerPrerendered" to render-mode="Server", and it would be called only once.

Just like this:

<app>
    <component type="typeof(App)" render-mode="Server" />
</app>

More details,you could refer to below article:

https://stackoverflow.com/questions/60996170/blazor-scoped-service-initializing-twice/61005960#61005960

Best regards,

Yijing Sun

Answer 2

User2110873642 posted

what are the downsides of  render-mode="Server"?

Answer 3

User475983607 posted

what are the downsides of  render-mode="Server"?

Screen could flash.  Read the Blazor life cycle docs.

https://docs.microsoft.com/en-us/aspnet/core/blazor/components/lifecycle?view=aspnetcore-3.1

Next, time please post your question in the Blazor forums this is Web Forms