Getting Started with Blazor Dialog Component in Web App

22 Feb 20249 minutes to read

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

Prerequisites

System requirements for Blazor components

Create a new Blazor Web App

You can create a Blazor Web App using Visual Studio 2022 via Microsoft Templates or the Syncfusion Blazor Extension.

You need to configure the corresponding Interactive render mode and Interactivity location while creating a Blazor Web Application.

Install Syncfusion Blazor Popups and Themes NuGet in the Blazor Web 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.

If you utilize WebAssembly or Auto render modes in the Blazor Web App need to be install Syncfusion Blazor components NuGet packages within the client project.

Alternatively, you can utilize the following package manager command to achieve the same.

Package Manager
Install-Package Syncfusion.Blazor.Popups -Version 27.2.2
Install-Package Syncfusion.Blazor.Themes -Version 27.2.2

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 Web App. For a app with WebAssembly or Auto (Server and WebAssembly) interactive render mode, register the Syncfusion Blazor service in both ~/Program.cs files of your web app.

....
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 reference in the <head> section and the script reference at the end of the <body> in the ~/Components/App.razor file as shown below:

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

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 Syncfusion Blazor Dialog component

Add the Syncfusion Blazor Dialog component in .razor file inside the Pages folder. If an interactivity location as Per page/component in the web app, define a render mode at top of the component, as follows:

RAZOR

@* desired render mode define here *@
@rendermode InteractiveAuto

RAZOR
<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.

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%;
}

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.

CSHTML
@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;
    }
}

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.

CSHTML
@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.

CSHTML
@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;
    }
}

Render Blazor Dialog with buttons

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

CSHTML
@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>

NOTE

View Sample in GitHub.