Getting Started with Blazor Predefined Dialogs in Blazor Web App

30 Jun 20269 minutes to read

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

Prerequisites

Create a new Blazor Web App in Visual Studio

Create a Blazor Web App using Visual Studio via Microsoft Templates or the Syncfusion® Blazor Extension. For detailed instructions, refer to the Blazor Web App Getting Started documentation.

Prerequisites

Create a new Blazor Web App in Visual Studio Code

Create a Blazor Web App using Visual Studio Code via Microsoft Templates or the Syncfusion® Blazor Extension. For detailed instructions, refer to the Blazor Web App Getting Started documentation.

For example, in a Blazor Web App with the Auto interactive render mode, use the following commands in the integrated terminal (Ctrl+`):

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

Prerequisites

Install the latest version of .NET SDK. If you previously installed the SDK, determine the installed version by executing the following command in a command prompt (Windows) or terminal (macOS) or command shell (Linux).

dotnet --version

Create a Blazor Web App using .NET CLI

Run the following command to create a new Blazor Web App in a command prompt (Windows) or terminal (macOS) or command shell (Linux). For detailed instructions, refer to the Blazor Web App Getting Started documentation.

For example, in a Blazor Web App with the Auto interactive render mode, use the following commands:

dotnet new blazor -o BlazorWebApp -int 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 required Blazor packages

Install the Syncfusion.Blazor.Popups and Syncfusion.Blazor.Themes NuGet packages using one of the following methods.

Visual Studio (NuGet Package Manager):

  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 it.

Visual Studio Code or .NET CLI:

Open the terminal or 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

If using the WebAssembly or Auto render modes in the Blazor Web App, install these packages in the client project.

NOTE

All Syncfusion Blazor packages are available on nuget.org. See the NuGet packages topic for details.

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.

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

Register Blazor service

Register the Blazor service in the Program.cs file of your Blazor Web App.

....
using Syncfusion.Blazor;
....
builder.Services.AddScoped<SfDialogService>();
builder.Services.AddSyncfusionBlazor();
....

NOTE

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.

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 ~/Components/App.razor 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>

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 opens predefined dialogs based on SfDialogService settings from anywhere in the application. Add SfDialogProvider in MainLayout.razor or in a specific page, but include it only once in the app. When added to MainLayout.razor, predefined dialogs are available throughout the application; when added to a specific page, dialogs are available only within that page.

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

Open Predefined Dialog

After adding SfDialogService and SfDialogProvider, open predefined dialogs from anywhere in the application using the AlertAsync, ConfirmAsync or PromptAsync methods in DialogService.

Show alert dialog

An alert dialog box is used to display errors, warnings, or informational messages that require user acknowledgment. This is achieved using the DialogService.AlertAsync method. The alert dialog displays an OK button. When the user selects OK, the alert dialog closes.

  • Open a Razor file located in the ~/Components/Pages (for example, Home.razor) and add the Blazor Predefined Dialogs component inside the razor file.
  • 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).

NOTE

If the Interactivity Location is set to Global with Auto or WebAssembly, the render mode is automatically configured in the App.razor file by default.

In the following example, an alert dialog is displayed upon clicking a 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";
    }
}

Run the application

Visual Studio:

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

Visual Studio Code or .NET CLI:

  1. Open the terminal (Visual Studio Code) or command prompt (.NET CLI) and navigate to the Client project folder.

  2. Run the following command:

     dotnet run
  3. The application will start and display in your default web browser.
Alert Dialog

Show confirm dialog

A confirm dialog displays a specified message with OK and Cancel buttons and returns a boolean value based on the user action. Selecting OK returns true; selecting Cancel returns false. Use the DialogService.ConfirmAsync method to show a confirm dialog, typically before a critical action. After the user responds, the dialog closes automatically.

In the following example, the confirm dialog is displayed and returns a value based on the OK or Cancel button click.

@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 collect input from the user using the DialogService.PromptAsync method. When the user selects OK, the input value is returned; selecting Cancel returns null. After the user responds, the dialog closes automatically.

In the following example, the prompt dialog is displayed and returns a value based on the OK or Cancel button click.

@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