Blazor Themes in Syncfusion Components

28 Mar 2022 / 24 minutes to read

The following list of themes are included in the Syncfusion Blazor components library.

Theme Style Sheet Name
Bootstrap 5 bootstrap5.css
Bootstrap 5 Dark bootstrap5-dark.css
Bootstrap 4 bootstrap4.css
Bootstrap 3 bootstrap.css
Bootstrap 3 Dark bootstrap-dark.css
Google’s Material material.css
Google’s Material-Dark material-dark.css
Tailwind CSS tailwind.css
Tailwind CSS Dark tailwind-dark.css
Fluent fluent.css
Fluent Dark fluent-dark.css
Microsoft Office Fabric fabric.css
Microsoft Office Fabric Dark fabric-dark.css
High Contrast highcontrast.css

The Syncfusion Blazor Bootstrap Theme is designed based on Bootstrap v3, whereas the Bootsrap4 theme is designed based on Bootstrap v4.

Reference themes in Blazor application

Syncfusion Blazor themes can be used in your Blazor application by referencing the style sheet.

  • For Blazor WebAssembly application, refer style sheet inside the <head> of wwwroot/index.html file.
  • For Blazor Server application, refer style sheet inside the <head> of
    • ~/Pages/_Host.cshtml file for .NET 3 and .NET 5.
    • ~/Pages/_Layout.cshtml for .NET 6.

Using the below approaches the themes can be referenced in the Blazor application,

  1. Static Web assets - Used to reference complete css via static web assests.
  2. CDN - Used to reference complete css via static web assests.
  3. CRG - Used to generate resources only for the selected (used) components.
  4. Theme Studio - Used to customize and generate themes only for the selected (used) components.
  5. NPM packages - Used to customize the existing themes and bundle stylesheet’s in an application.

Instead of using Static Web assets or a CDN reference, you can reference the style sheet into your projects to customize the theme or bundle it with the other style sheets using NPM packages.

Static Web Assets

Enable static web assets usage

To use static web assets, ensure UseStaticFiles method is called as follows,

  • For .NET 6 app, open the ~/Program.cs file and call UseStaticFiles method.
  • For .NET 5 and .NET 3.X app, open the ~/Startup.cs file and call UseStaticFiles method.

For Blazor WASM App, call UseStaticFiles method in Server project in the above mentioned file.

Refer theme style sheet from static web assets

Syncfusion Blazor themes are available as static web assets in the Syncfusion.Blazor.Themes and Syncfusion.Blazor NuGet Packages.

  • For Blazor WebAssembly application, refer style sheet inside the <head> element of wwwroot/index.html file.
  • For Blazor Server application, refer style sheet inside the <head> element of
    • ~/Pages/_Host.cshtml file for .NET 3 and .NET 5.
    • ~/Pages/_Layout.cshtml for .NET 6.

When using individual NuGet packages in your application, add Syncfusion.Blazor.Themes NuGet Package and reference style sheet as below,

<head>
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
</head>

When using Syncfusion.Blazor NuGet package,

<head>
    <link href="_content/Syncfusion.Blazor/styles/bootstrap5.css" rel="stylesheet" />
</head>

CDN reference

Instead of using a local resource on your server, you can use a cloud CDN to reference the theme style sheets. CDN Stands for “Content Delivery Network”. A CDN is a group of servers distributed in different locations. While CDNs are often used to host websites, they are commonly used to provide other types of downloadable data as well. Examples include software programs, images, videos, and streaming media.

Syncfusion Blazor Themes are available in the CDN. Make sure that the version in the URLs matches the version of the Syncfusion Blazor Package you are using.

<head>
    <link href="https://cdn.syncfusion.com/blazor/20.1.55/styles/bootstrap5.css" rel="stylesheet"/>
</head>
Theme Name CDN Reference
Bootstrap 5 https://cdn.syncfusion.com/blazor/20.1.55/styles/bootstrap5.css
Bootstrap 5 Dark https://cdn.syncfusion.com/blazor/20.1.55/styles/bootstrap5-dark.css
Bootstrap 4 https://cdn.syncfusion.com/blazor/20.1.55/styles/bootstrap4.css
Bootstrap 3 https://cdn.syncfusion.com/blazor/20.1.55/styles/bootstrap.css
Bootstrap 3 Dark https://cdn.syncfusion.com/blazor/20.1.55/styles/bootstrap-dark.css
Google’s Material https://cdn.syncfusion.com/blazor/20.1.55/styles/material.css
Google’s Material Dark https://cdn.syncfusion.com/blazor/20.1.55/styles/material-dark.css
Tailwind CSS https://cdn.syncfusion.com/blazor/20.1.55/styles/tailwind.css
Tailwind CSS Dark https://cdn.syncfusion.com/blazor/20.1.55/styles/tailwind-dark.css
Fluent https://cdn.syncfusion.com/blazor/20.1.55/styles/fluent.css
Fluent Dark https://cdn.syncfusion.com/blazor/20.1.55/styles/fluent-dark.css
Microsoft Office Fabric https://cdn.syncfusion.com/blazor/20.1.55/styles/fabric.css
Microsoft Office Fabric Dark https://cdn.syncfusion.com/blazor/20.1.55/styles/fabric-dark.css
High Contrast https://cdn.syncfusion.com/blazor/20.1.55/styles/highcontrast.css

NPM packages

NPM is a node package manager. It is basically used for managing dependencies of various server-side dependencies. You can manage server-side dependencies manually. It is a command-line program for dealing with said repository that aids in package installation, version management, and dependency management. It is an online repository for the publishing of open-source Node.js projects.

You can add the theme for the Blazor applications through npm packages using the SCSS files by following the below process.

  • Install Web Compiler to use SCSS files in Blazor applications.

  • To install Web Compiler, open Visual Studio and click the Extensions in the toolbar.

    Themes-npm-package-extension

    Themes-npm-package-webcompiler

  • Install the Syncfusion node_modules in this application using this command.

      npm install @syncfusion/ej2

  • Create a SCSS file as ~/wwwroot/styles/custom.scss and provide the variables to override as shown below.

      $primary: blue !default;
  @import 'ej2/fabric.scss';

  • Right-click the SCSS file and click the Web Compiler to compile the file.

    Themes-npm-packages-compile

  • The compiler config.json file is created. Then, provide the location of the compiled CSS file and include a path as shown in the following code snippet.

      [
    {
      "outputFile": "wwwroot/styles/customstyle.css",
      "inputFile": "wwwroot/styles/customstyle.scss",
      "options": {
        "includePath": "node_modules/@syncfusion"
      }
    }
  ]

  • The SCSS file has been compiled to the CSS file. Then, add this CSS file to the <head> element of the ~/Pages/_Host.cshtml page.

  • Run the application and see the fabric themes from installed npm packages were applied.

Change theme dynamically

In the Blazor application, the application theme can be changed dynamically by changing its style sheet reference in code.

Change theme dynamically in Blazor server app

The following example demonstrates how to change a theme dynamically in Blazor Server application using Syncfusion Blazor themes using Syncfusion Dropdown component.

  1. Below step shows how to reference style sheet in the way to change at dynamically.

    • For .NET6 Blazor Server Application, In the _Layout.cshtml the theme is changed dynamically using id in setTheme method.
    • For .NET5 & 3.1 Blazor Server Application, In _Host.cshtml, the theme is changed based on query string.
<head>
... 
<link id="theme" href="_content/Syncfusion.Blazor.Themes/bootstrap4.css" rel="stylesheet" />
</head>
... 
<script>
    function setTheme(theme) {
        document.getElementsByTagName('body')[0].style.display = 'none';
        let synclink = document.getElementById('theme');
        synclink.href = '_content/Syncfusion.Blazor.Themes/' + theme + '.css';
        setTimeout(function () { document.getElementsByTagName('body')[0].style.display = 'block'; }, 200);
    }
</script>
...
@page "/"
@namespace BlazorThemeSwitcher.Pages
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
    
@{
    Layout = null;
    QueryHelpers.ParseQuery(Request.QueryString.Value).TryGetValue("theme", out var themeName);
    themeName = themeName.Count > 0 ? themeName.First() : "bootstrap4";
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>BlazorThemeSwitcher</title>
    <base href="~/" />
    <link rel="stylesheet" href="css/bootstrap/bootstrap.min.css" />
    <link href="css/site.css" rel="stylesheet" />
    <link href="BlazorThemeSwitcher.styles.css" rel="stylesheet" />
    <link href=@("_content/Syncfusion.Blazor.Themes/" + themeName + ".css")rel="stylesheet" />
</head>

<body>
    <script src="_framework/blazor.server.js"></script>
</ </body>
</html>

  1. Below step shows changing style sheet dynamically.

    • For .NET5 Blazor Server Application, in MainLayout.razor page add dropdown list with themes. In ValueChange event handler, the page is refreshed by changing query string to change the theme in application.

    • For .NET6 Blazor Server Application, modify the MainLayout.razor page add dropdown list with themes. In ValueChange event handler, the theme is changed by calling setTheme method defined in step `.

@inherits LayoutComponentBase
@inject NavigationManager UrlHelper;
@inject IJSRuntime JSRuntime;
@using Syncfusion.Blazor.DropDowns;
@using Syncfusion.Blazor.Buttons;
@using Microsoft.AspNetCore.WebUtilities;

<div class="page">
    <div class="main">
        <div class="top-row px-4">
            <div class="theme-switcher">
                @*Theme switcher*@
                <SfDropDownList TItem="ThemeDetails" TValue="string" @bind-Value="themeName" DataSource="@Themes">
                    <DropDownListFieldSettings Text="Text" Value="ID"></DropDownListFieldSettings>
                    <DropDownListEvents TItem="ThemeDetails" TValue="string" ValueChange="OnThemeChange"></DropDownListEvents>
                </SfDropDownList>
            </div>
            <a href="http://blazor.net" target="_blank" class="ml-md-auto">About</a>
        </div>

        <div class="content px-4">
            @Body
        </div>
    </div>
</div>

@code {
    private string themeName;

    public class ThemeDetails
    {
        public string ID { get; set; }
        public string Text { get; set; }
    }

    private List<ThemeDetails> Themes = new List<ThemeDetails>() {
        new ThemeDetails(){ ID = "material", Text = "Material" },
        new ThemeDetails(){ ID = "bootstrap", Text = "Bootstrap" },
        new ThemeDetails(){ ID = "fabric", Text = "Fabric" },
        new ThemeDetails(){ ID = "bootstrap4", Text = "Bootstrap 4" },
        new ThemeDetails(){ ID = "tailwind", Text = "TailWind"},
        new ThemeDetails(){ ID = "tailwind-dark", Text = "TailWind Dark" },
        new ThemeDetails(){ ID = "material-dark", Text = "Material Dark" },
        new ThemeDetails(){ ID = "bootstrap-dark", Text = "Bootstrap Dark" },
        new ThemeDetails(){ ID = "fabric-dark", Text = "Fabric Dark" },
        new ThemeDetails(){ ID = "highcontrast", Text = "High Contrast" }
    };
    

    public void OnThemeChange(Syncfusion.Blazor.DropDowns.ChangeEventArgs<string, ThemeDetails> args)
    {
        JSRuntime.InvokeAsync<object>("setTheme", args.ItemData.ID);                
    }
    
    private string GetThemeName()
    {
        var uri = UrlHelper.ToAbsoluteUri(UrlHelper.Uri);
        QueryHelpers.ParseQuery(uri.Query).TryGetValue("theme", out var theme);
        return theme.Count > 0 ? theme.First() : "bootstrap4";
    }

    protected override void OnInitialized()
    {
        var theme = GetThemeName();
        themeName = theme.Contains("bootstrap4") ? "bootstrap4" : theme;
    }

}
@inherits LayoutComponentBase
@inject NavigationManager UrlHelper;
@using Syncfusion.Blazor.DropDowns;
@using Syncfusion.Blazor.Buttons;
@using Microsoft.AspNetCore.WebUtilities

<div class="page">
    <div class="main">
        <div class="top-row px-4">
            <div class="theme-switcher">
                @*Theme switcher*@
                <SfDropDownList TItem="ThemeDetails" TValue="string" @bind-Value="themeName" DataSource="@Themes">
                    <DropDownListFieldSettings Text="Text" Value="ID"></DropDownListFieldSettings>
                    <DropDownListEvents TItem="ThemeDetails" TValue="string" ValueChange="OnThemeChange"></DropDownListEvents>
                </SfDropDownList>
            </div>
            <a href="http://blazor.net" target="_blank" class="ml-md-auto">About</a>
        </div>

        <div class="content px-4">
            @Body
        </div>
    </div>
</div>

@code {
    private string themeName;

    public class ThemeDetails
    {
        public string ID { get; set; }
        public string Text { get; set; }
    }
    
    private List<ThemeDetails> Themes = new List<ThemeDetails>() {
        new ThemeDetails(){ ID = "material", Text = "Material" },
        new ThemeDetails(){ ID = "bootstrap", Text = "Bootstrap" },
        new ThemeDetails(){ ID = "fabric", Text = "Fabric" },
        new ThemeDetails(){ ID = "bootstrap4", Text = "Bootstrap 4" },
        new ThemeDetails(){ ID = "tailwind", Text = "TailWind"},
        new ThemeDetails(){ ID = "tailwind-dark", Text = "TailWind Dark" },
        new ThemeDetails(){ ID = "material-dark", Text = "Material Dark" },
        new ThemeDetails(){ ID = "bootstrap-dark", Text = "Bootstrap Dark" },
        new ThemeDetails(){ ID = "fabric-dark", Text = "Fabric Dark" },
        new ThemeDetails(){ ID = "highcontrast", Text = "High Contrast" }
    };
    
    public void OnThemeChange(ChangeEventArgs<string, ThemeDetails> args)
    {
        var theme = GetThemeName();
        if (theme != args.ItemData.ID)
        {
            UrlHelper.NavigateTo(GetUri(args.ItemData.ID ), true);
        }
    }
    
    private string GetThemeName()
    {
        var uri = UrlHelper.ToAbsoluteUri(UrlHelper.Uri);
        QueryHelpers.ParseQuery(uri.Query).TryGetValue("theme", out var theme);
        return theme.Count > 0 ? theme.First() : "bootstrap4";
    }
    
    private string GetUri(string themeName)
    {
        var uri = UrlHelper.ToAbsoluteUri(UrlHelper.Uri);
        return uri.AbsolutePath + "?theme=" + themeName;
    }
    
    protected override void OnInitialized()
    {
        var theme = GetThemeName();
        themeName = theme.Contains("bootstrap4") ? "bootstrap4" : theme;
    }
}

Change theme dynamically in blazor server app

View sample in GitHub

Change theme dynamically in blazor WebAssembly (WASM) app

The following example demonstrates how to change a theme dynamically in Blazor WebAssembly using the application with the Syncfusion Blazor themes using Syncfusion Dropdown component.

  1. Add the below function code in the index.html file to set the theme as selected in dropdown by using its id value.

     <head>
 ... 
 <link id="theme" href="_content/Syncfusion.Blazor.Themes/bootstrap4.css" rel="stylesheet" />
 </head>
 ... 
 <script>
     function setTheme(theme) {
         document.getElementsByTagName('body')[0].style.display = 'none';
         let synclink = document.getElementById('theme');
         synclink.href = '_content/Syncfusion.Blazor.Themes/' + theme + '.css';
         setTimeout(function () { document.getElementsByTagName('body')[0].style.display = 'block'; }, 200);
     }
 </script>
 ...

  2. Modify the MainLayout.razor page with the below code to implement a theme change dynamically using the dropdown by its id value in javascript function in the application.

     @inherits LayoutComponentBase
 @inject NavigationManager UrlHelper;
 @inject IJSRuntime JSRuntime;
 @using Syncfusion.Blazor.DropDowns;
 @using Syncfusion.Blazor.Buttons;
 @using Microsoft.AspNetCore.WebUtilities;
    
 <div class="page">
     <div class="main">
         <div class="top-row px-4">
             <div class="theme-switcher">
                 @*Theme switcher*@
                 <SfDropDownList TItem="ThemeDetails" TValue="string" @bind-Value="themeName" DataSource="@Themes">
                     <DropDownListFieldSettings Text="Text" Value="ID"></DropDownListFieldSettings>
                     <DropDownListEvents TItem="ThemeDetails" TValue="string" ValueChange="OnThemeChange"></DropDownListEvents>
                 </SfDropDownList>
             </div>
             <a href="http://blazor.net" target="_blank" class="ml-md-auto">About</a>
         </div>
    
         <div class="content px-4">
             @Body
         </div>
     </div>
 </div>
    
 @code {
     private string themeName;
    
     public class ThemeDetails
     {
         public string ID { get; set; }
         public string Text { get; set; }
     }
    
     private List<ThemeDetails> Themes = new List<ThemeDetails>() {
         new ThemeDetails(){ ID = "material", Text = "Material" },
         new ThemeDetails(){ ID = "bootstrap", Text = "Bootstrap" },
         new ThemeDetails(){ ID = "fabric", Text = "Fabric" },
         new ThemeDetails(){ ID = "bootstrap4", Text = "Bootstrap 4" },
         new ThemeDetails(){ ID = "tailwind", Text = "TailWind"},
         new ThemeDetails(){ ID = "tailwind-dark", Text = "TailWind Dark" },
         new ThemeDetails(){ ID = "material-dark", Text = "Material Dark" },
         new ThemeDetails(){ ID = "bootstrap-dark", Text = "Bootstrap Dark" },
         new ThemeDetails(){ ID = "fabric-dark", Text = "Fabric Dark" },
         new ThemeDetails(){ ID = "highcontrast", Text = "High Contrast" }
     };
        
    
     public void OnThemeChange(Syncfusion.Blazor.DropDowns.ChangeEventArgs<string, ThemeDetails> args)
     {
         JSRuntime.InvokeAsync<object>("setTheme", args.ItemData.ID);                
     }
     
     private string GetThemeName()
     {
         var uri = UrlHelper.ToAbsoluteUri(UrlHelper.Uri);
         QueryHelpers.ParseQuery(uri.Query).TryGetValue("theme", out var theme);
         return theme.Count > 0 ? theme.First() : "bootstrap4";
     }
    
     protected override void OnInitialized()
     {
         var theme = GetThemeName();
         themeName = theme.Contains("bootstrap4") ? "bootstrap4" : theme;
     }
    
 }

    Change theme dynamically in blazor WASM app

    View sample in GitHub

See also

How to change background of browser based on Syncfusion Theme in Blazor?