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Index

@page "/"
@using Microsoft.AspNetCore.Components

@foreach (var sub in subs)
{
    <MatButton @ref="@sub.Button"
               Label="@sub.SubName" 
               OnClick="@((_) => OnClick(sub.Button, sub.Menu, sub.SubName))">
    </MatButton>
    <MatMenu @ref="@sub.Menu">
        <MatList>
            <MatListItem>@sub.SubName</MatListItem>
        </MatList>
    </MatMenu>
}
<h1>@text</h1>

<Button @onclick="RefreshMenu">Refresh Menu</Button>
 
@functions
{
    public class Sub
    {
        public string SubName {set; get;} 
        public BaseMatButton Button {set; get;} 
        public BaseMatMenu Menu {set; get;} 
    }

    List<Sub> subs = new List<Sub> 
    {
        new Sub() { SubName="A", Button=null, Menu=null },
        new Sub() { SubName="B", Button=null, Menu=null },
        new Sub() { SubName="C", Button=null, Menu=null },
    };

    string text = "";

    public void OnClick(BaseMatButton button, BaseMatMenu menu, string sub)
    {
        text=(menu == null ? "Menu is null" : sub);
        menu.OpenAsync(button.Ref);      
    }

    private void RefreshMenu() {
        subs = new List<Sub> 
        {
            new Sub() { SubName="A2", Button=null, Menu=null },
            new Sub() { SubName="B2", Button=null, Menu=null },
            new Sub() { SubName="C2", Button=null, Menu=null },
        };
    }

}

namespace BlazorFiddleProject
{
    using Microsoft.AspNetCore.Components.Builder;
    using Microsoft.Extensions.DependencyInjection;


    public class Startup
    {
        
        public void ConfigureServices(IServiceCollection services)
        {
        }

        public void Configure(IComponentsApplicationBuilder app)
        {
            app.AddComponent<App>("app");
        }
    }
}

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8"/>
    <meta name="viewport" content="width=device-width">
    <title>BlazorFiddleProject</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">

    <style>
        app { }
    </style>

    <script type="text/javascript">
    </script>
</head>
<body>
<app>Loading...</app>

<script src="_framework/blazor.webassembly.js"></script>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</body>
</html>

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