Getting Started with Blazor Diagram in Blazor Server App

This section explains the step-by-step process of integrating the Blazor Diagram component into your Blazor Server app using Visual Studio, Visual Studio Code and .NET CLI. We’ll break it down into simple steps to make it easy to follow. Additionally, you can find a fully functional example project on our GitHub repository.

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Using .NET CLI Templates

Quickly set up a Blazor application using the preconfigured Syncfusion Web App Template.

First, install the template using the .NET CLI.

dotnet new install Syncfusion.Blazor.WebApp.Templates

Next, create a new project with following command.

dotnet new syncfusionblazorwebapp --name MyApp --interactivity Server

After creating the project, navigate to the main project folder (for example, MyApp) and run the following command.

  • .NET CLI
    • cd MyApp
dotnet run

    Manually creating a new Blazor Server App

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

    Run the following command to create a new Blazor Server App.

    dotnet new blazor -o BlazorServerApp --interactivity Server
cd BlazorServerApp

    Alternatively, create a Blazor Server App using Visual Studio Code via Microsoft Templates, the Syncfusion® Blazor Extension, or the C# Dev Kit extension.

    Configure the appropriate Interactive render mode and Interactivity location while creating a Blazor Server App. For detailed information, refer to the interactive render mode documentation.

    Install the required Blazor packages

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

    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 them.

    Alternatively, you can install the same packages using the Package Manager Console with the following commands.

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

    Open the terminal 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

    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 the Blazor service

    Open the Program.cs file in Blazor Server App and register the Blazor service and include the required namespace reference using Syncfusion.Blazor; at the top.

    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 at the end of the <head> section in the App.razor file.

    <link href="_content/Syncfusion.Blazor.Themes/fluent2.css" rel="stylesheet" />

    Include the required script references at the end of the <body> section in the App.razor file to enable Diagram functionality.

    <script src="_content/Syncfusion.Blazor.Diagram/scripts/sf-diagramcomponent.min.js" type="text/javascript"></script>

    Add Blazor Diagram component

    Open a Razor file located in the ~/Components/Pages/*.razor (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 Server App, define a render mode at the top of the razor file. (For example, InteractiveServer, InteractiveWebAssembly or InteractiveAuto). If the Interactivity is set to Global with Auto or WebAssembly, the render mode is automatically configured in the App.razor file by default.

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

    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.

    @using Syncfusion.Blazor.Diagram

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

@code {
    DiagramObjectCollection<Node> nodes = new DiagramObjectCollection<Node>();
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();
    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

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

    Open the terminal and run the following command.

    dotnet run

    The output will appear as follows:

    Getting Started in Blazor Diagram