Getting Started with Blazor Dialog Component

9 Sep 20258 minutes to read

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

To get start quickly with Blazor Dialog component, you can check on this video or GitHub sample.

Prerequisites

Create a new Blazor App in Visual Studio

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

Install Syncfusion® Blazor Popups and Themes NuGet in the 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. Alternatively, you can utilize the following package manager command to achieve the same.

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

Create a new Blazor App in Visual Studio Code

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

Alternatively, you can create a WebAssembly application using the following command in the terminal(Ctrl+`).

dotnet new blazorwasm -o BlazorApp
cd BlazorApp

Install Syncfusion® Blazor Popups and Themes NuGet in the App

  • 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.
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

Open ~/_Imports.razor file and import the Syncfusion.Blazor and Syncfusion.Blazor.Popups namespace.

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

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

using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
using Syncfusion.Blazor;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.Add<App>("#app");
builder.RootComponents.Add<HeadOutlet>("head::after");

builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });

builder.Services.AddSyncfusionBlazor();
await builder.Build().RunAsync();
....

Add stylesheet and script resources

The theme stylesheet and script can be accessed from NuGet through Static Web Assets. Include the stylesheet and script references in the <head> section of the ~/index.html file.

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

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 Blazor Dialog component

Add the Syncfusion® Blazor Dialog component in the ~/Pages/Index.razor file.

<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.
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

See also

NOTE

You can also explore our Blazor Dialog example that shows you how to render and configure the Dialog.