ExCollapse

<ExCollapse Title="ExCollapse" @bind-Expand="_expand" >
    <ChildContent>
        <Span>Content</Span>
    </ChildContent>
    <CloseHeaderContent>
        <Span TextColor="TextColor.Danger">Closed Header Content</Span>
    </CloseHeaderContent>
</ExCollapse>
<Switch @bind-Checked="_expand">Toggle</Switch>
@code
{
    bool _expand = true;
}

Expand=false Expand=true