Getting Started with Blazor Diagram in Blazor Web App

This section briefly explains how to include the Blazor Diagram component in your Blazor Web App using Visual Studio, Visual Studio Code, or the .NET CLI.

NOTE

The Blazor Diagram component requires .NET 8.0 or later and a modern browser with ES6 and WebAssembly support. The Syncfusion.Blazor.Diagram package is compatible with the Server, WebAssembly, and Auto interactive render modes.

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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.

NOTE

Configure the appropriate Interactive render mode and Interactivity location while creating the project.
If you use the Syncfusion® Blazor Extension, a sample application can be generated automatically.

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.

NOTE

Configure the appropriate Interactive render mode and Interactivity location while creating the project.
If you use the Syncfusion® Blazor Extension, a sample application can be generated automatically.

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 --interactivity Auto -f net8.0
cd BlazorWebApp

This command creates a new Blazor Web App and places it in a new directory called BlazorWebApp inside your current location.

NOTE

See the dotnet new CLI command and interactive render mode documentation topics for more details.

Install required Blazor packages

Install the Syncfusion.Blazor.Diagram 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.Diagram and Syncfusion.Blazor.Themes) and install it.

Visual Studio (Package Manager Console): run the following in Tools → NuGet Package Manager → Package Manager Console:

Install-Package Syncfusion.Blazor.Diagram -Version 34.2.2
Install-Package Syncfusion.Blazor.Themes -Version 34.2.2

Visual Studio Code or .NET CLI:

Open the terminal or command prompt and run the following commands:

dotnet add package Syncfusion.Blazor.Diagram --version 34.2.2
dotnet add package Syncfusion.Blazor.Themes --version 34.2.2
dotnet restore

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 and import the Syncfusion.Blazor and Syncfusion.Blazor.Diagram namespaces.

@using Syncfusion.Blazor
@using Syncfusion.Blazor.Diagram

Register Blazor service

Register the Blazor service in the Program.cs file.

using Syncfusion.Blazor;
....
var builder = WebApplication.CreateBuilder(args);
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.

NOTE

Register your Syncfusion license key before calling AddSyncfusionBlazor() by using Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("YOUR_LICENSE_KEY"). A missing or invalid license will cause trial license warnings at runtime. See the Syncfusion Licensing FAQ for details.

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.

<head>
    ...
    <link href="_content/Syncfusion.Blazor.Themes/fluent2.css" rel="stylesheet" />
</head>
<body>
    ....
    <script src="_content/Syncfusion.Blazor.Diagram/scripts/sf-diagramcomponent.min.js" type="text/javascript"></script>
</body>

NOTE

After adding the stylesheet and script references, rebuild the project so that the static web assets from the NuGet packages are restored to the wwwroot/_content/ folder.

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 Diagram Component

  • Open a Razor file located in the ~/Components/Pages (for example, Home.razor) and add the Blazor Diagram component inside the razor file.
  • If the interactivity location is set to Per page/component in the Blazor Web App, define a render mode at the top of the razor file. (For example, InteractiveServer, InteractiveWebAssembly or InteractiveAuto).

If your application uses Per page/component interactivity, add the render mode declaration at the top of Pages/Home.razor:

@rendermode InteractiveAuto
@using Syncfusion.Blazor.Diagram

<SfDiagramComponent Width="100%" Height="600px"/>

The @using Syncfusion.Blazor.Diagram directive can be omitted if it is already declared in ~/_Imports.razor (as described in the previous step).

NOTE

The following table shows which render mode to choose for each hosting model:

Hosting model Render mode Use case
Server @rendermode InteractiveServer Server-side rendering with SignalR.
WebAssembly @rendermode InteractiveWebAssembly Client-side rendering, no server required after first load.
Auto @rendermode InteractiveAuto WebAssembly on first visit, then Server for subsequent visits.

Create your first Diagram with nodes and connectors

This section explains how to create a simple flowchart by adding nodes, customizing their appearance, and connecting them using connectors.

The following example creates a flowchart with four nodes: Start, Process, Decision, and End. It also applies common node and connector settings using the NodeCreating and ConnectorCreating properties.

<SfDiagramComponent Width="100%" Height="600px" Nodes="@nodes" Connectors="@connectors" NodeCreating="@NodeCreating" ConnectorCreating="@ConnectorCreating" />

@code {
    DiagramObjectCollection<Node> nodes;
    DiagramObjectCollection<Connector> connectors;
    protected override void OnInitialized()
    {
        nodes = new DiagramObjectCollection<Node>()
        {
            new Node()
            {
               ID = "node1", OffsetX = 300, OffsetY = 100,
               Shape = new FlowShape() { Type = NodeShapes.Flow, Shape = NodeFlowShapes.Terminator },
               Annotations = new DiagramObjectCollection<ShapeAnnotation>()
               {
                  new ShapeAnnotation(){ Content = "Start" }
               }
            },
            new Node()
            {
               ID = "node2", OffsetX = 300, OffsetY = 200,
               Shape = new FlowShape() { Type = NodeShapes.Flow, Shape = NodeFlowShapes.Process },
               Annotations = new DiagramObjectCollection<ShapeAnnotation>()
               {
                  new ShapeAnnotation(){ Content = "Process" }
               }
            },
            new Node()
            { 
               ID = "node3", OffsetX = 300, OffsetY = 300,
               Shape = new FlowShape() { Type = NodeShapes.Flow, Shape = NodeFlowShapes.Decision },
               Annotations = new DiagramObjectCollection<ShapeAnnotation>()
               {
                  new ShapeAnnotation(){ Content = "Decision?" }
               }
            },
            new Node()
            {
               ID = "node4", OffsetX = 300, OffsetY = 400,
               Shape = new FlowShape() { Type = NodeShapes.Flow, Shape = NodeFlowShapes.Terminator },
               Annotations = new DiagramObjectCollection<ShapeAnnotation>()
               {
                  new ShapeAnnotation(){ Content = "End" }
               }
            }
        };
        connectors = new DiagramObjectCollection<Connector>()
        {
            new Connector()
            {
                ID = "connector1",
                SourceID = "node1",
                TargetID = "node2",
            },
            new Connector()
            {
                ID = "connector2",
                SourceID = "node2",
                TargetID = "node3",
            },
            new Connector()
            {
                ID = "connector3",
                SourceID = "node3",
                TargetID = "node4",
            },
        };
    }

    private void NodeCreating(IDiagramObject obj)
    {
        Node node = obj as Node;
        node.Style = new ShapeStyle() { Fill = "#E8F4FF", StrokeColor = "#357BD2" };
        node.Width = 140;
        node.Height = 50;
    }

    private void ConnectorCreating(IDiagramObject obj)
    {
        (obj as Connector).Type = ConnectorSegmentType.Orthogonal;
    }
}

A complete working sample can be downloaded from GitHub

In this example:

Run the application

Visual Studio: Press Ctrl+F5 (Windows) or ⌘+F5 (macOS) to launch the application. The Blazor Diagram 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 at the URL shown in the console output (for example, https://localhost:7xxx or https://localhost:5xxx).

The output will appear as follows:

Getting Started in Blazor Diagram