Getting Started with Blazor Dialog Component

23 Apr 202511 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 29.1.33
Install-Package Syncfusion.Blazor.Themes -Version 29.1.33

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 29.1.33
dotnet add package Syncfusion.Blazor.Themes -v 29.1.33
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%;
}

Prerender the Blazor dialog

The dialog component is maintained in the DOM after hiding the dialog when the AllowPrerender property is set to true.

  • By default, the AllowPrerender is set to false where the dialog DOM elements are destroyed while hiding the dialog and each time the dialog will be re-rendered when showing the dialog. The @bind-Visible property of dialog also works based on the AllowPrerender property.
  • If the AllowPrerender property is set to true, the dialog elements are maintained in the DOM when hiding the dialog.
@using Syncfusion.Blazor.Buttons

@using Syncfusion.Blazor.Popups
<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" IsModal="true">
        <DialogTemplates>
            <Header> Dialog </Header>
            <Content> This is a dialog with header </Content>
        </DialogTemplates>
    </SfDialog>
</div>
<style>
    #target {
        height: 500px;
    }
</style>
@code {
    private bool Visibility { get; set; } = true;
    private void OnBtnClick()
    {
        this.Visibility = true;
    }
}

Prerender Blazor Dialog

A modal shows an overlay behind the Dialog. So, the users must interact with the Dialog before interacting with the remaining content in an application.

While the user clicks the overlay, the action can be handled through the OnOverlayClick event. In the following code, it explains the Dialog close action performed while clicking the overlay.

@using Syncfusion.Blazor.Buttons

<SfButton @onclick="@OpenDialog">Open Modal Dialog</SfButton>

<SfDialog Width="250px" IsModal="true" @bind-Visible="@IsVisible">
    <DialogEvents OnOverlayModalClick="@OnOverlayclick">
    </DialogEvents>
    <DialogTemplates>
        <Content> This is a modal dialog </Content>
    </DialogTemplates>
</SfDialog>

@code {
    private bool IsVisible { get; set; } = true;

    private void OpenDialog()
    {
        this.IsVisible = true;
    }

    private void OnOverlayclick(OverlayModalClickEventArgs arg)
    {
        this.IsVisible = false;
    }
}

Enable header

The Dialog header can be enabled by adding the header content as text or HTML content using the Header template of the dialog.

@using Syncfusion.Blazor.Buttons

<SfButton @onclick="@OpenDialog">Open Dialog</SfButton>

<SfDialog Width="250px" ShowCloseIcon="true" IsModal="true" @bind-Visible="@IsVisible">
    <DialogTemplates>
        <Header> Dialog </Header>
        <Content> This is a dialog with header </Content>
    </DialogTemplates>
</SfDialog>

@code {
    private bool IsVisible { get; set; } = true;

    private void OpenDialog()
    {
        this.IsVisible = true;
    }
}

Blazor Dialog with Header

Render Blazor Dialog with buttons

By adding the DialogButtons can render a Dialog with buttons in Razor page.

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

<SfButton @onclick="@OpenDialog">Open Dialog</SfButton>

<SfDialog Width="250px" ShowCloseIcon="true" IsModal="true" @bind-Visible="@IsVisible">
    <DialogTemplates>
        <Header> Dialog </Header>
        <Content> This is a Dialog with button and primary button </Content>
    </DialogTemplates>
    <DialogButtons>
        <DialogButton Content="OK" IsPrimary="true" OnClick="@OkClick" />
        <DialogButton Content="Cancel" OnClick="@CancelClick" />
    </DialogButtons>
    <span id="message">@ClickStatus</span>
</SfDialog>

@code {
    private bool IsVisible { get; set; } = true;

    private string ClickStatus { get; set; }

    private void OpenDialog()
    {
        this.IsVisible = true;
        this.ClickStatus = "";
    }

    private void CancelClick()
    {
        this.ClickStatus = "you have clicked Cancel";
        this.IsVisible = false;
    }
    private void OkClick()
    {
        this.ClickStatus = "you have clicked Ok";
        this.IsVisible = true;
    }
}
<style>
    #message {
        color: blue;
    }
</style>

Blazor Dialog with Buttons

See also

NOTE

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