Getting Started with Blazor Dialog Component

23 Dec 20259 minutes to read

This section briefly explains about how to include Blazor Dialog component in a Blazor WebAssembly App using Visual Studio, Visual Studio Code, and the .NET CLI.

To get start quickly with Blazor Dialog component, refer this GitHub sample.

• Visual Studio
• Visual Studio Code
• .NET CLI

Prerequisites

• System requirements for Blazor components

Create a new Blazor App in Visual Studio

Create a Blazor WebAssembly App using Visual Studio via Microsoft Templates or the Syncfusion^® Blazor Extension. For detailed instructions, refer to the Blazor WASM App Getting Started documentation.

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

To add the Blazor Dialog component in the app, open the NuGet package manager in Visual Studio (Tools → NuGet Package Manager → Manage NuGet Packages for Solution), then search and install Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes. Alternatively, run the following commands in the Package Manager Console to achieve the same.

Package Manager

Install-Package Syncfusion.Blazor.Popups -Version 32.1.19
Install-Package Syncfusion.Blazor.Themes -Version 32.1.19

NOTE

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

Prerequisites

• System requirements for Blazor components

Create a new Blazor App in Visual Studio Code

Create a Blazor WebAssembly App using Visual Studio Code via Microsoft Templates or the Syncfusion^® Blazor Extension. For detailed instructions, refer to the Blazor WASM App Getting Started documentation.

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

Blazor WASM App

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 in the project root directory where the .csproj file is located.
• Run the following command to install the Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes NuGet packages and ensure all dependencies are installed.

Package Manager

dotnet add package Syncfusion.Blazor.Popups -v 32.1.19
dotnet add package Syncfusion.Blazor.Themes -v 32.1.19
dotnet restore

NOTE

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

Prerequisites

Install the latest version of .NET SDK. If the .NET SDK is already installed, determine the installed version by running the following command in a command prompt (Windows), terminal (macOS), or command shell (Linux).

.NET CLI

dotnet --version

Create a Blazor WebAssembly App using .NET CLI

Run the following command to create a new Blazor WebAssembly App in a command prompt (Windows) or terminal (macOS) or command shell (Linux). For detailed instructions, refer to this Blazor WASM App Getting Started documentation.

.NET CLI

dotnet new blazorwasm -o BlazorApp
cd BlazorApp

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

To add the Blazor Dialog component to the application, run the following commands in a command prompt (Windows), command shell (Linux), or terminal (macOS) to install the Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes NuGet packages. See Install and manage packages using the dotnet CLI for more details.

.NET CLI

dotnet add package Syncfusion.Blazor.Popups -Version 32.1.19
dotnet add package Syncfusion.Blazor.Themes -Version 32.1.19
dotnet restore

NOTE

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

Add Import Namespaces

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

~/_Imports.razor

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

Register Syncfusion^® Blazor Service

Register the Syncfusion^® Blazor Service in the ~/Program.cs file of the Blazor WebAssembly App.

~/Program.cs

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 within 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 Blazor application. Also, check out the Adding Script Reference topic to learn different approaches for adding script references in Blazor application.

Add Blazor Dialog component

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

CSHTML

<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 the default web browser.

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>

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>

See also

• Getting Started with Syncfusion^® Blazor for client-side in .NET Core CLI

• Getting Started with Syncfusion^® Blazor for server-side in Visual Studio

• Getting Started with Syncfusion^® Blazor for server-side in .NET Core CLI

NOTE

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