Getting Started with Blazor Dialog Component in Web App

14 Aug 202511 minutes to read

This section briefly explains about how to include Blazor Dialog component in your Blazor Web App using Visual Studio and Visual Studio Code.

Prerequisites

System requirements for Blazor components

Create a new Blazor Web App in Visual Studio

You can create a Blazor Web App using Visual Studio 2022 via Microsoft Templates or the Syncfusion^® Blazor Extension.

You need to configure the corresponding Interactive render mode and Interactivity location while creating a Blazor Web Application.

Install Syncfusion^® Blazor Popups and Themes NuGet in the Blazor Web App

To add Blazor Dialog component in the app, open the NuGet package manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), search and install Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes.

If you utilize WebAssembly or Auto render modes in the Blazor Web App need to be install Syncfusion^® Blazor components NuGet packages within the client project.

Alternatively, you can utilize the following package manager command to achieve the same.

Package Manager
Install-Package Syncfusion.Blazor.Popups -Version 31.1.17
Install-Package Syncfusion.Blazor.Themes -Version 31.1.17

NOTE

Syncfusion^® Blazor components are available in nuget.org. Refer to NuGet packages topic for available NuGet packages list with component details.

Prerequisites

System requirements for Blazor components

Create a new Blazor Web App in Visual Studio Code

You can create a Blazor Web App using Visual Studio Code via Microsoft Templates or the Syncfusion^® Blazor Extension.

You need to configure the corresponding Interactive render mode and Interactivity location while creating a Blazor Web Application.

For example, in a Blazor Web App with the Auto interactive render mode, use the following commands.

Blazor Web App
dotnet new blazor -o BlazorWebApp -int Auto
cd BlazorWebApp
cd BlazorWebApp.Client

NOTE

For more information on creating a Blazor Web App with various interactive modes and locations, refer to this link.

Install Syncfusion^® Blazor Popups and Themes NuGet in the App

If you utilize WebAssembly or Auto render modes in the Blazor Web App need to be install Syncfusion^® Blazor components NuGet packages within the client project.

Press Ctrl+` to open the integrated terminal in Visual Studio Code.
Ensure you’re in the project root directory where your .csproj file is located.
Run the following command to install a Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes NuGet package and ensure all dependencies are installed.

Package Manager
dotnet add package Syncfusion.Blazor.Popups -v 31.1.17
dotnet add package Syncfusion.Blazor.Themes -v 31.1.17
dotnet restore

NOTE

Syncfusion^® Blazor components are available in nuget.org. Refer to NuGet packages topic for available NuGet packages list with component details.

Register Syncfusion^® Blazor Service

Interactive Render Mode	Description
WebAssembly or Auto	Open ~/_Imports.razor file from the client project.
Server	Open ~/_import.razor file, which is located in the `Components` folder.

Import the Syncfusion.Blazor and Syncfusion.Blazor.Popups namespace.

~/_Imports.razor
@using Syncfusion.Blazor
@using Syncfusion.Blazor.Popups

Now, register the Syncfusion^® Blazor Service in the ~/Program.cs file of your Blazor Web App.

If the Interactive Render Mode is set to WebAssembly or Auto, you need to register the Syncfusion^® Blazor service in both ~/Program.cs files of your Blazor Web App.

Server(~/_Program.cs)
Client(~/_Program.cs)
...
...
using Syncfusion.Blazor;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents()
    .AddInteractiveWebAssemblyComponents();
builder.Services.AddSyncfusionBlazor();

var app = builder.Build();
....
...
using Syncfusion.Blazor;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.Services.AddSyncfusionBlazor();

await builder.Build().RunAsync();

If the Interactive Render Mode is set to Server, your project will contain a single ~/Program.cs file. So, you should register the Syncfusion^® Blazor Service only in that ~/Program.cs file.

~/_Program.cs
...
using Syncfusion.Blazor;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorComponents()
    .AddInteractiveServerComponents();
builder.Services.AddSyncfusionBlazor();

var app = builder.Build();
....

Add stylesheet and script resources

The theme stylesheet and script can be accessed from NuGet through Static Web Assets. Include the stylesheet reference in the <head> section and the script reference at the end of the <body> in the ~/Components/App.razor file as shown below:

<head>
    ....
    <link href="_content/Syncfusion.Blazor.Themes/bootstrap5.css" rel="stylesheet" />
</head>
....
<body>
    ....
    <script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>
</body>

NOTE

Check out the Blazor Themes topic to discover various methods (Static Web Assets, CDN, and CRG) for referencing themes in your Blazor application. Also, check out the Adding Script Reference topic to learn different approaches for adding script references in your Blazor application.

Add Syncfusion^® Blazor Dialog component

Add the Syncfusion^® Blazor Dialog component in .razor file inside the Pages folder. If an interactivity location as Per page/component in the web app, define a render mode at top of the component, as follows:

Interactivity location	RenderMode	Code
Per page/component	Auto	@rendermode InteractiveAuto
	WebAssembly	@rendermode InteractiveWebAssembly
	Server	@rendermode InteractiveServer
	None	—

NOTE

If an Interactivity Location is set to Global and the Render Mode is set to Auto or WebAssembly or Server, the render mode is configured in the App.razor file by default.

RAZOR

@* desired render mode define here *@
@rendermode InteractiveAuto

RAZOR
<SfDialog Width="250px">
    <DialogTemplates>
        <Content> This is a Dialog with content </Content>
    </DialogTemplates>
</SfDialog>

Press Ctrl+F5 (Windows) or ⌘+F5 (macOS) to launch the application. This will render the Syncfusion^® Blazor Dialog component in your default web browser.

Blazor Dialog

NOTE

In the dialog control, max-height is calculated based on the dialog target element height. If the Target property is not configured, the document.body is considered as a target. Therefore, to show a dialog in proper height, you need to add min-height to the target element.

NOTE

If the dialog is rendered based on the body, then the dialog will get the height based on its body element height. If the height of the dialog is larger than the body height, then the dialog’s height will not be set. For this scenario, you can set the CSS style for the html and body to get the dialog height.

CS
html, body {
   height: 100%;
}

Created and Destroyed Events

The Created event fires when the dialog is initialized and rendered in the DOM.
The Destroyed event triggers when the dialog component is removed from the DOM. These lifecycle events allow executing custom code at specific points in the component’s existence.

@using Syncfusion.Blazor.Popups

<SfDialog>
    <DialogEvents Created="@CreatedHandler" Destroyed="@DestroyedHandler"></DialogEvents>
</SfDialog>
@code {

    public void CreatedHandler(Object args)
    {
        // Here, you can customize your code.
    }

    private void DestroyedHandler()
    {
        // Here, you can customize your code.
    }
}

Prerender the Dialog

The AllowPrerender property controls how the dialog DOM elements are handled when the dialog is hidden. Understanding this property is crucial for optimizing performance in your application.

By default, AllowPrerender is set to false. In this mode, dialog DOM elements are completely removed from the DOM when the dialog is hidden, and recreated each time the dialog is shown. This approach saves memory but requires re-rendering on each display.
When AllowPrerender is set to true, the dialog elements remain in the DOM even when hidden, which improves performance for frequently accessed dialogs but uses more memory.

@using Syncfusion.Blazor.Popups
@using Syncfusion.Blazor.Buttons

<div id="target">
    <div>
        <button class="e-btn" @onclick="@OnBtnClick">Open</button>
    </div>
    <SfDialog Target="#target" Width="300px" ShowCloseIcon="true" @bind-Visible="Visibility" AllowPrerender="true" Header="AllowPrerender Dialog" Content="This is a dialog with content">
    </SfDialog>
</div>
<style>
    #target {
        height: 500px;
    }
</style>
@code {
    private bool Visibility { get; set; } = false;
    private void OnBtnClick()
    {
        this.Visibility = true;
    }
}

Set Header to Dialog

The Header property allows rendering a dialog with custom text header.

@using Syncfusion.Blazor.Popups

<SfDialog Width="250px" Header="Dialog Header"></SfDialog>

Blazor Dialog with Header

Set Content to Dialog

The Content property allows rendering a dialog with custom text content.

@using Syncfusion.Blazor.Popups

<SfDialog Width="250px" Content="This is a dialog with Content property."></SfDialog>

Blazor Dialog with Content

NOTE

View Sample in GitHub.

Getting Started with Blazor Dialog Component in Web App

Prerequisites

Create a new Blazor Web App in Visual Studio

Install Syncfusion® Blazor Popups and Themes NuGet in the Blazor Web App

Prerequisites

Create a new Blazor Web App in Visual Studio Code

Install Syncfusion® Blazor Popups and Themes NuGet in the App

Register Syncfusion® Blazor Service

Add stylesheet and script resources

Add Syncfusion® Blazor Dialog component

Created and Destroyed Events

Prerender the Dialog

Set Header to Dialog

Set Content to Dialog

See also

Install Syncfusion^® Blazor Popups and Themes NuGet in the Blazor Web App

Install Syncfusion^® Blazor Popups and Themes NuGet in the App

Register Syncfusion^® Blazor Service

Add Syncfusion^® Blazor Dialog component