Getting Started with Blazor Dialog Component in Blazor Web App

9 Jul 20269 minutes to read

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

Create a new Blazor Web App

• Visual Studio
• Visual Studio Code
• .NET CLI

Create a Blazor Web App using Visual Studio via Microsoft Templates or the Blazor Extension.

Run the following command to create a new Blazor Web App.

Terminal

dotnet new blazor -o BlazorWebApp --interactivity Auto
cd BlazorWebApp
cd BlazorWebApp.Client

Alternatively, create a Blazor Web App using Visual Studio Code via Microsoft Templates, the Blazor Extension, or the C# Dev Kit extension.

Run the following command to create a new Blazor Web App.

Command Prompt

dotnet new blazor -o BlazorWebApp --interactivity Auto
cd BlazorWebApp
cd BlazorWebApp.Client

NOTE

Configure the appropriate Interactive render mode and Interactivity location while creating a Blazor Web App. For detailed information, refer to the interactive render mode documentation.

Install the required Blazor packages

Install the Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes NuGet packages. All Syncfusion Blazor packages are available on nuget.org. See the NuGet packages topic for details. If using the WebAssembly or Auto render modes in the Blazor Web App, install these packages in the .Client project.

• Visual Studio
• Visual Studio Code
• .NET CLI

1. Go to Tools → NuGet Package Manager → Manage NuGet Packages for Solution.
2. Search the required NuGet packages (Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes) and install them.

Alternatively, you can install the same packages using the Package Manager Console with the following commands.

Package Manager Console

Install-Package Syncfusion.Blazor.Popups -Version 34.1.29
Install-Package Syncfusion.Blazor.Themes -Version 34.1.29

Open the terminal and run the following commands.

Terminal

dotnet add package Syncfusion.Blazor.Popups -v 34.1.29
dotnet add package Syncfusion.Blazor.Themes -v 34.1.29

Open the command prompt and run the following commands.

Command Prompt

dotnet add package Syncfusion.Blazor.Popups -v 34.1.29
dotnet add package Syncfusion.Blazor.Themes -v 34.1.29

Add import namespaces

After the packages are installed, open the ~/_Imports.razor file in the .Client project and import the Syncfusion.Blazor and Syncfusion.Blazor.Popups namespaces.

~/_Imports.razor

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

Register the Blazor service

Open the Program.cs file in the Blazor Web App and register the Blazor service. If the Interactive Render Mode is set to WebAssembly or Auto, register the Blazor service in Program.cs files of both the server and client projects in your Blazor Web App.

Program.cs

....
using Syncfusion.Blazor;
....
builder.Services.AddSyncfusionBlazor();
....

Add stylesheet and script resources

The theme stylesheet and script can be accessed from NuGet through Static Web Assets. Include the stylesheet and the script references in the App.razor file.

App.razor

...
<link href="_content/Syncfusion.Blazor.Themes/fluent2.css" rel="stylesheet" />
...
<script src="_content/Syncfusion.Blazor.Core/scripts/syncfusion-blazor.min.js" type="text/javascript"></script>

Add Blazor Dialog component

Open a Razor file located in the ~/Pages/*.razor (for example, Home.razor) and add the Blazor Dialog component inside the Razor file.

NOTE

If the interactivity location is set to Per page/component in the Web App, define a render mode at the top of the razor file (For example, InteractiveServer, InteractiveWebAssembly or InteractiveAuto). If the Interactivity is set to Global with Auto or WebAssembly, the render mode is automatically configured in the App.razor file by default.

Home.razor

@rendermode InteractiveAuto

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

Run the application

• Visual Studio
• Visual Studio Code
• .NET CLI

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

Open the terminal and navigate to the main project folder (for example, BlazorWebApp) and run the following command.

Terminal

cd ..
cd BlazorWebApp
dotnet run

Open the command prompt and navigate to the main project folder (for example, BlazorWebApp) and run the following command.

Command Prompt

cd ..
cd BlazorWebApp
dotnet run

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.

app.css

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.

Home.razor

<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.

Home.razor

@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 a custom text header.

Home.razor

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

Set Content to Dialog

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

Home.razor

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

NOTE

View Sample in GitHub.

See also

1. Getting Started with Blazor WebAssembly App
2. Getting Started with Blazor Server App
3. Getting Started with Blazor Dialog Template