How do I animate state transitions in Blazor?

In the following example, we’ve animated state transitions using CSS in a Blazor app.

When the state is changed, adding and removing the property values for every state transition is animated.

Create a separate reusable component (.razor) in the Pages folder and add the animation.

[Pages/AnimeState.razor]

<div class="container @(IsShown?"spin-in":"fade-out")">
    <span>@(Name??"")</span>
</div>

<style>
    .container{
        display:inline-block;
        width:@width;
        height:@height;
        color:white;
        background-color:blue;
    }

    .fade-out{
       animation: fade @AnimationTime linear forwards;
    }

    .spin-in{
       animation: spin @AnimationTime linear forwards;
    }

    @@keyframes fade {
      0%   {opacity:1;}
      99%  {width:@width; height:@height;}
      100% {width:0px;height:0px; opacity:0;}
    }

    @@keyframes spin {
      0%   {width:0px;height:0px; transform: rotate(0deg);}
      99%  {width:@width; height:@height;}
      100% {width:@width;height:@height;transform: rotate(1440deg);}
    }
</style>

@code {
    string width = "100px";
    string height = "20px";

    [Parameter] public string Name { get; set; }
    [Parameter] public string AnimationTime { get; set; }
    [Parameter] public bool IsShown { get; set; }
}

Add the AnimeState.razor component and define the property value to be animated when the state has been changed.

[Index.razor]

@page "/"

<button class="btn btn-primary" @onclick="OnButtonClick">Switch</button>
<AnimeState Name="Blazor" AnimationTime="2s" IsShown=@isShown />
<span>State transition Animation</span>
@code{
    bool isShown = true;

    private void OnButtonClick() 
    {
        isShown = !isShown;
    }
}

View Sample in GitHub