Getting Started with Predefined Dialogs in Blazor

30 Jan 20247 minutes to read

This section briefly explains how to include the predefined dialogs in your Blazor Server App and Blazor WebAssembly App using Visual Studio.

Prerequisites

Create a new Blazor App in Visual Studio

You can create a Blazor Server App or 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 predefined 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 26.1.35
Install-Package Syncfusion.Blazor.Themes -Version 26.1.35

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 and Sycnfusion Dialog 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 Server App or Blazor WebAssembly App.

using Syncfusion.Blazor
using Syncfusion.Blazor.Popups

// Add services to the container.
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddScoped<SfDialogService>();
builder.Services.AddSyncfusionBlazor();

var app = builder.Build();
....
using Syncfusion.Blazor
using Syncfusion.Blazor.Popups

// Add services to the container.

builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
builder.Services.AddScoped<SfDialogService>();
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. Reference the stylesheet and script in the <head> of the main page as follows:

  • For .NET 6 Blazor Server app, include it in ~/Pages/_Layout.cshtml file.

  • For .NET 7 Blazor Server app, include it in the ~/Pages/_Host.cshtml file.

  • For Blazor WebAssembly app, include it in 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 Provider

SfDialogProvider allows to open predefined dialogs based on SfDialogService settings from any where in application. You can add SfDialogProvider in MainLayout.razor or any page. But it should be added only once in the app. If you add in MainLayout.razor, you can open predefined dialogs from any where in application. If you add in particular page, you can open dialogs only within the page.

  • Now, add SfDialogProvider in the ~/_MainLayout.razor file.
<Syncfusion.Blazor.Popups.SfDialogProvider/>

Open Predefined Dialog

Once you added SfDialogService and SfDialogProvider, you can open predefined dialogs from any where in application using AlertAsync,ConfirmAsync or PromptAsync methods in DialogServices.

Show alert dialog

An alert dialog box used to display an errors, warnings, and information alerts that needs user awareness. This can be achieved by using the DialogService.AlertAsync method. The alert dialog is displayed along with the OK button. When user clicks on OK button, alert dialog will get closed.

In the code example below, an alert dialog is displayed upon clicking the button using the Syncfusion Blazor Button Component.

@using Syncfusion.Blazor.Popups
@using Syncfusion.Blazor.Buttons
@inject SfDialogService DialogService
    <div>
        <SfButton @onclick="@AlertBtn">Alert</SfButton>
    </div>
    <div class="status" style ="padding-top:10px">@DialogStatus</div>
@code {
    private string DialogStatus { get; set; }
    private async Task AlertBtn()
    {
        await DialogService.AlertAsync("10% of battery remaining", "Low Battery");
        this.DialogStatus = "The user closed the Alert dialog";
    }
}
Alert Dialog

Show confirm dialog

A confirm dialog box used to displays a specified message along with the OK and Cancel buttons, which returns a boolean value according to the user’s click action. When the user clicks the OK button, the true value is returned otherwise it will returns the false value. This can be achieved by using the DialogService.ConfirmAsync method. It is used to get approval from the user, and it appears before any critical action. After get approval from the user the dialog will disappear automatically.

In the below code example, the confirm dialog displayed on OK and Cancel button click action.

@using Syncfusion.Blazor.Popups
@using Syncfusion.Blazor.Buttons
@inject SfDialogService DialogService
    <div>
        <SfButton @onclick="@ConfirmBtn">Confirm</SfButton>
    </div>
    <div class="status" style ="padding-top:10px">
    @DialogStatus
</div>
@code {
    private string DialogStatus { get; set; }
    private async Task ConfirmBtn()
    {
        bool isConfirm = await DialogService.ConfirmAsync("Are you sure you want to permanently delete these items?", "Delete Multiple Items");
        string confirmMessage = isConfirm ? "confirmed" : "canceled";
        this.DialogStatus = $"The user {confirmMessage} the dialog box."; 
    }
}
Confirm Dialog

Show prompt dialog

A prompt dialog is used to get the input from the user by using the DialogService.PromptAsync method. When the user clicks the OK button the input value from the dialog is returned. If the user clicks the Cancel button the null value is returned. After getting the input from the user the dialog will disappear automatically.

In the below code example, the prompt dialog displayed on OK and Cancel button click action.

@using Syncfusion.Blazor.Popups
@using Syncfusion.Blazor.Buttons
@inject SfDialogService DialogService
    <div>
        <SfButton @onclick="@PromptBtn">Prompt</SfButton>
    </div>
    <div class="status" style ="padding-top:10px">
    @DialogStatus
</div>
@code {
    private string DialogStatus { get; set; }
    
    private async Task PromptBtn()
    {
        string promptText = await DialogService.PromptAsync("Enter your name:", "Join Chat Group");

        this.DialogStatus = $"Input from the user is returned as \"{promptText}\".";
    }
}
Prompt Dialog