Getting Started with Blazor Diagram Component in Web App

16 Feb 202414 minutes to read

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

Prerequisites

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 Diagram and Themes NuGet in the Blazor Web App

To add Blazor Diagram 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.Diagram 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.

Install-Package Syncfusion.Blazor.Diagram -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

Open ~/_Imports.razor file and import the Syncfusion.Blazor and Syncfusion.Blazor.Diagram namespace.

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

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 Diagram component

Add the Syncfusion Blazor Diagram 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:

@* desired render mode define here *@
@rendermode InteractiveAuto
<SfDiagramComponent Width="100%" Height="600px"/>
  • Press Ctrl+F5 (Windows) or +F5 (macOS) to launch the application. This will render the Syncfusion Blazor Diagram component in your default web browser.

Basic Blazor Diagram elements

  • Node: Visualize any graphical object using nodes, which can be arranged and manipulated at the same time on a Blazor diagram page.
  • Connector: Represents the relationship between two nodes. Three types of connectors provided as follows:
    1) Orthogonal
    2) Bezier
    3) Straight
  • Port: Acts as the connection points of node or connector and allows you to create connections with only specific points.
  • Annotation: Additional information can be shown by adding text or labels on nodes and connectors.

How to create Blazor flowchart diagram

Let us create and add a Node with specific position, size, label, and shape. Connect two or more nodes by using a Connector.

<SfDiagramComponent @ref="@diagram" Connectors="@connectors" Height="700px" Nodes="@nodes" />

@code
{
    SfDiagramComponent diagram;
    int connectorCount = 0;
    //Defines Diagram's nodes collection.
    DiagramObjectCollection<Node> nodes = new DiagramObjectCollection<Node>();
    //Defines Diagram's connectors collection.
    DiagramObjectCollection<Connector> connectors = new DiagramObjectCollection<Connector>();

    protected override void OnInitialized()
    {
        InitDiagramModel();
    }

    private void InitDiagramModel()
    {
        CreateNode("Start", 300, 50, NodeFlowShapes.Terminator, "Start");
        CreateNode("Init", 300, 140, NodeFlowShapes.Process, "var i = 0");
        CreateNode("Condition", 300, 230, NodeFlowShapes.Decision, "i < 10?");
        CreateNode("Print", 300, 320, NodeFlowShapes.PreDefinedProcess, "print(\'Hello!!\');");
        CreateNode("Increment", 300, 410, NodeFlowShapes.Process, "i++;");
        CreateNode("End", 300, 500, NodeFlowShapes.Terminator, "End");
        // Creates orthogonal connector.
        OrthogonalSegment segment1 = new OrthogonalSegment()
        {
            Type = ConnectorSegmentType.Orthogonal,
            Direction = Direction.Right,
            Length = 30,
        };
        OrthogonalSegment segment2 = new OrthogonalSegment()
        {
            Type = ConnectorSegmentType.Orthogonal,
            Length = 300,
            Direction = Direction.Bottom,
        };
        OrthogonalSegment segment3 = new OrthogonalSegment()
        {
            Type = ConnectorSegmentType.Orthogonal,
            Length = 30,
            Direction = Direction.Left,
        };
        OrthogonalSegment segment4 = new OrthogonalSegment()
        {
            Type = ConnectorSegmentType.Orthogonal,
            Length = 200,
            Direction = Direction.Top,
        };
        CreateConnector("Start", "Init");
        CreateConnector("Init", "Condition");
        CreateConnector("Condition", "Print");
        CreateConnector("Condition", "End", "Yes", segment1, segment2);
        CreateConnector("Print", "Increment", "No");
        CreateConnector("Increment", "Condition", null, segment3, segment4);
    }

    // Method to create connector.
    private void CreateConnector(string sourceId, string targetId, string label = default(string), OrthogonalSegment segment1 = null, OrthogonalSegment segment2 = null)
    {
        Connector diagramConnector = new Connector()
        {
            // Represents the unique id of the connector.
            ID = string.Format("connector{0}", ++connectorCount),
            SourceID = sourceId,
            TargetID = targetId,
        };
        if (label != default(string))
        {
            // Represents the annotation of the connector.
            PathAnnotation annotation = new PathAnnotation()
            {
                Content = label,
                Style = new TextStyle() { Fill = "white" }
            };
            diagramConnector.Annotations = new DiagramObjectCollection<PathAnnotation>() { annotation };
        }
        if (segment1 != null)
        {
            // Represents the segment type of the connector.
            diagramConnector.Type = ConnectorSegmentType.Orthogonal;
            diagramConnector.Segments = new DiagramObjectCollection<ConnectorSegment> { segment1, segment2 };
        }
        connectors.Add(diagramConnector);
    }

    // Method to create node.
    private void CreateNode(string id, double x, double y, NodeFlowShapes shape, string label)
    {
        Node diagramNode = new Node()
        {
            //Represents the unique id of the node.
            ID = id,
            // Defines the position of the node.
            OffsetX = x,
            OffsetY = y,
            // Defines the size of the node.
            Width = 145,
            Height = 60,
            // Defines the style of the node.
            Style = new ShapeStyle { Fill = "#357BD2", StrokeColor = "White" },
            // Defines the shape of the node.
            Shape = new FlowShape() { Type = NodeShapes.Flow, Shape = shape },
            // Defines the annotation collection of the node.
            Annotations = new DiagramObjectCollection<ShapeAnnotation>
            {
                new ShapeAnnotation
                {
                    Content = label,
                    Style = new TextStyle()
                    {
                        Color="White",
                        Fill = "transparent"
                    }
                }
            }
        };
        nodes.Add(diagramNode);
    }
}
Blazor Diagram Component

NOTE

View Sample in GitHub.

How to create organizational chart

A built-in automatic layout algorithm is specifically designed for organizational charts to arrange parent and child node positions automatically.

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

<SfDiagramComponent Height="600px" NodeCreating="@OnNodeCreating" ConnectorCreating="@OnConnectorCreating">
    <DataSourceSettings ID="Id" ParentID="Team" DataSource="@DataSource"></DataSourceSettings>
    <SnapSettings>
        <HorizontalGridLines LineColor="white" LineDashArray="2,2">
        </HorizontalGridLines>
        <VerticalGridLines LineColor="white" LineDashArray="2,2">
        </VerticalGridLines>
    </SnapSettings>
    <Layout Type="LayoutType.OrganizationalChart" @bind-HorizontalSpacing="@HorizontalSpacing" @bind-VerticalSpacing="@VerticalSpacing" GetLayoutInfo="GetLayoutInfo">
    </Layout>
</SfDiagramComponent>

@code
{
    //Initializing layout.
    int HorizontalSpacing = 40;
    int VerticalSpacing = 50;

    //To configure every subtree of the organizational chart.
    private TreeInfo GetLayoutInfo(IDiagramObject obj, TreeInfo options)
    {
        options.AlignmentType = SubTreeAlignmentType.Right;
        options.Orientation = Orientation.Vertical;
        return options;
    }

    //Creates node with some default values.
    private void OnNodeCreating(IDiagramObject obj)
    {
        Node node = obj as Node;
        node.Height = 50;
        node.Width = 150;
        node.Style = new ShapeStyle() { Fill = "#6495ED", StrokeWidth = 1, StrokeColor = "Black" };
    }

    //Creates connectors with some default values.
    private void OnConnectorCreating(IDiagramObject connector)
    {
        Connector connectors = connector as Connector;
        connectors.Type = ConnectorSegmentType.Orthogonal;
        connectors.Style = new TextStyle() { StrokeColor = "#6495ED", StrokeWidth = 1 };
        connectors.TargetDecorator = new DecoratorSettings
        {
            Shape = DecoratorShape.None,
            Style = new ShapeStyle() { Fill = "#6495ED", StrokeColor = "#6495ED", }
        };
    }

    public class OrgChartDataModel
    {
        public string Id { get; set; }
        public string Team { get; set; }
        public string Role { get; set; }
    }
    public object DataSource = new List<object>()
    {
        new OrgChartDataModel() { Id= "1", Role= "General Manager" },
        new OrgChartDataModel() { Id= "2", Role= "Human Resource Manager", Team= "1" },
        new OrgChartDataModel() { Id= "3", Role= "Design Manager", Team= "1" },
        new OrgChartDataModel() { Id= "4", Role= "Operation Manager", Team= "1" },
        new OrgChartDataModel() { Id= "5", Role= "Marketing Manager", Team= "1" }
    };
}
Blazor Organization Diagram ChildNode in Vertical Right

See also

  1. Getting Started with Syncfusion Blazor for client-side in .NET Core CLI
  2. Getting Started with Syncfusion Blazor for client-side in Visual Studio
  3. Getting Started with Syncfusion Blazor for server-side in .NET Core CLI