Getting Started with Blazor Dialog in Blazor WASM App

30 Jun 20268 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.

Create a new Blazor WebAssembly (Standalone) App

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

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

dotnet new blazorwasm -o BlazorApp
cd BlazorApp

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

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

dotnet new blazorwasm -o BlazorApp
cd BlazorApp

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.

  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.

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.

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.

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 and import the Syncfusion.Blazor and Syncfusion.Blazor.Popups namespaces.

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

Register the Blazor service

Open the Program.cs file in Blazor WebAssembly App and register the Blazor service.

....
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 script references in the ~wwwroot/index.html file.

...
<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.

@using Syncfusion.Blazor.Popups

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

Run the application

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 run the following command.

dotnet run

Open the command prompt and run the following command.

dotnet run
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%;
}

NOTE

View sample in GitHub.

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

  1. Getting Started with Blazor for client-side in .NET Core CLI
  2. Getting Started with Blazor for server-side in Visual Studio
  3. Getting Started with Blazor for server-side in .NET Core CLI