LEADTOOLS includes more than 30 built-in annotation objects that can be extended to create custom annotation objects. This tutorial demonstrates how to create a custom circle annotation derived from the AnnEllipseObject
class in a C# WinForms application using the Document Viewer.
Overview | |
---|---|
Summary | This tutorial covers both the automated and custom annotation features in a C# WinForms application using the Document Viewer. |
Completion Time | 45 minutes |
Visual Studio Project | Download tutorial project (14 KB) |
Platform | WinForms C# Application |
IDE | Visual Studio 2019, 2022 |
Development License | Download LEADTOOLS |
Try it in another language |
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Get familiar with the basic steps of creating a project, initializing the Document Viewer, and adding annotations to the Document Viewer by reviewing the tutorials below, before working on the Create a Custom Annotation with the Document Viewer - WinForms C# tutorial.
Start with a copy of the project created in the Draw and Edit Annotation on Documents tutorial. If the project is not available, follow the steps in that tutorial to create it.
The references needed depend upon the purpose of the project. References can be added by one or the other of the following two methods (but not both). For this project, the references below are needed.
If using NuGet references, this tutorial requires the following NuGet packages and their dependencies:
Leadtools.Annotations.WinForms
Leadtools.Document.Sdk
Leadtools.Document.Viewer.WinForms
If local DLL references are used, the following DLLs are needed. The DLLs are located at <INSTALL_DIR>\LEADTOOLS22\Bin\Dotnet4\x64
:
Leadtools.dll
Leadtools.Annotations.Automation.dll
Leadtools.Annotations.Engine.dll
Leadtools.Annotations.WinForms.dll
Leadtools.Annotations.Rendering.WinForms.dll
Leadtools.Caching.dll
Leadtools.Codecs.dll
Leadtools.Controls.WinForms.dll
Leadtools.Document.dll
Leadtools.Document.Pdf.dll
Leadtools.Document.Viewer.WinForms.dll
For a complete list of which DLL files are required for your application, refer to Files to be Included in your Application.
The License unlocks the features needed for the project. It must be set before any toolkit function is called. For details, including tutorials for different platforms, refer to the Setting a Runtime License tutorial.
There are two types of runtime licenses:
With the references added, the license set, and the Document Viewer initialized, coding can begin.
Go to Form1.cs
in the Solution Explorer. Right-click on the Design Window and select View Code or press F7 to bring up the code behind the Form.
Add the following statements to the using
block at the top:
using System;
using System.IO;
using System.Drawing;
using System.Windows.Forms;
using Leadtools;
using Leadtools.Controls;
using Leadtools.Caching;
using Leadtools.Annotations.WinForms;
using Leadtools.Annotations.Designers;
using Leadtools.Annotations.Automation;
using Leadtools.Document;
using Leadtools.Document.Viewer;
First download the Circle icon PNG image. Extract it and re-name the PNG file to Create-a-Custom-Annotation-Circle-Icon.png
.
In the Solution Explorer, drop down the Properties tab, and double-click Resources.resx.
Click Add Resource and then click Add Existing File...
Browse to the location where you saved the Circle icon PNG image and click Open. After the resource has been imported, the project will create a Resources
folder.
This image needs to be embedded into the project. To do so, navigate to Solution Explorer, drop down the Resources folder
, and click on Create-a-Custom-Annotation-Circle-Icon.png
. In the image's properties, change Build Action to embedded resource.
In the Solution Explorer, right-click the Project, highlight Add, and click Create Folder. Rename the folder to be AnnCircleObject
.
In the Solution Explorer, right-click the AnnCircleObject
folder, highlight Add, and click Class....
Add three new classes:
AnnCircleDrawDesigner.cs
AnnCircleObject.cs
AnnCircleObjectRenderer.cs
Note
Be sure to change the namespace for each of these classes to match the namespace in Form1.cs.
Add the below code to the AnnCircleDrawDesigner
class:
using System;
using Leadtools;
using Leadtools.Annotations.Engine;
using Leadtools.Annotations.Designers;
namespace Create_a_Custom_Annotation
{
class AnnCircleDrawDesigner : AnnRectangleDrawDesigner
{
//We need 2 points, a beginning and an ending point
private LeadPointD begin = LeadPointD.Empty;
private LeadPointD end = LeadPointD.Empty;
/// <summary>
/// Contstructor for the AnnCircleDrawDesigner
/// </summary>
public AnnCircleDrawDesigner(IAnnAutomationControl automationControl, AnnContainer container, AnnCircleObject annObject)
: base(automationControl, container, annObject) { }
/// <summary>
/// override the pointer down event
/// set the beginning and ending points to the location of the first click
/// </summary>
public override bool OnPointerDown(AnnContainer sender, AnnPointerEventArgs e)
{
begin = e.Location;
end = begin;
return base.OnPointerDown(sender, e);
}
/// <summary>
/// override the pointer move event
/// set the new mouse point to the end variable
/// do some math to create a circle object (width/height stay equal)
/// </summary>
public override bool OnPointerMove(AnnContainer sender, AnnPointerEventArgs e)
{
end = e.Location;
AnnCircleObject circle = (AnnCircleObject)TargetObject;
double x = (end.X - begin.X);
double y = Math.Abs(end.Y - begin.Y);
double scaleX = 1;
double scaleY = 1;
if (x < y)
scaleX = y / x;
else
scaleY = x / y;
circle.Rect = LeadRectD.Create(begin.X, begin.Y, Math.Abs(end.X - begin.X) * Math.Abs(scaleX), Math.Abs(end.Y - begin.Y) * Math.Abs(scaleY));
Invalidate(LeadRectD.Empty);
return true;
}
}
}
Add the below code to the AnnCircleObject
class:
using Leadtools.Annotations.Engine;
namespace Create_a_Custom_Annotation
{
class AnnCircleObject : AnnEllipseObject
{
//set the id to the UserObjectID
public const int CircleObjectId = UserObjectId;
/// <summary>
/// Constructor for the object
/// set the id of the object to the circle object ID
/// </summary>
public AnnCircleObject()
: base()
{
SetId(CircleObjectId);
Tag = null;
}
protected override AnnObject Create()
{
return new AnnCircleObject();
}
}
}
Add the below code to the AnnCircleObjectRenderer
class:
using System.Collections.Generic;
using Leadtools.Annotations.Rendering;
using Leadtools.Annotations.Automation;
using Leadtools.Annotations.Engine;
using Leadtools;
namespace Create_a_Custom_Annotation
{
class AnnCircleObjectRenderer : AnnEllipseObjectRenderer
{
/// <summary>
/// Constructor for the renderer
/// get the ellipse object renderer and use the same styles for the circle
/// </summary>
public AnnCircleObjectRenderer(AnnAutomationManager manager)
: base()
{
IAnnObjectRenderer annEllipseObjRenderer = manager.RenderingEngine.Renderers[AnnObject.EllipseObjectId];
LabelRenderer = annEllipseObjRenderer.LabelRenderer;
LocationsThumbStyle = annEllipseObjRenderer.LocationsThumbStyle;
RotateCenterThumbStyle = annEllipseObjRenderer.RotateCenterThumbStyle;
RotateGripperThumbStyle = annEllipseObjRenderer.RotateGripperThumbStyle;
// The below snippet changes the annotation's thumbnail size
//LeadSizeD newThumbSize = LeadSizeD.Create(300, 300); // New size of the thumbnails, change as necessary
//LocationsThumbStyle.Size = newThumbSize;
//RotateCenterThumbStyle.Size = newThumbSize;
//RotateGripperThumbStyle.Size = newThumbSize;
}
/// <summary>
/// override the RenderThumbs method
/// go through the thumbs and remove the top bottom left and right thumbs so it cannot be changed from a circle
/// </summary>
public override void RenderThumbs(AnnContainerMapper mapper, LeadPointD[] thumbLocations, AnnFixedStateOperations operations)
{
List<LeadPointD> newThumbs = new List<LeadPointD>();
for (int i = 0; i < thumbLocations.Length; i += 2)
newThumbs.Add(thumbLocations[i]);
base.RenderThumbs(mapper, newThumbs.ToArray(), operations);
}
}
}
Right-click on Form1.cs
in the Solution Explorer and select View Code to bring up the code behind the form.
Add inside the InitAnnotations()
method the CreateCustomObject(automationManager);
code, below var automationManagerHelper = new AutomationManagerHelper(automationManager);
as follows:
var automationManagerHelper = new AutomationManagerHelper(automationManager);
CreateCustomObject(automationManager);
Add a new method inside the Form1
class named CreateCustomObject(AnnAutomationManager annManager)
. This method is called inside the InitAnnotations()
method as shown above. Add the below code to the new method:
private void CreateCustomObject(AnnAutomationManager annManager)
{
// Create the circle object, assign the designers, set the toolbar image, and then add it to the manager and rendering engine
AnnAutomationObject circleAutomationObject = new AnnAutomationObject();
circleAutomationObject.Id = AnnCircleObject.CircleObjectId;
circleAutomationObject.Name = "Circle";
circleAutomationObject.ToolBarToolTipText = circleAutomationObject.Name;
circleAutomationObject.DrawDesignerType = typeof(AnnCircleDrawDesigner);
circleAutomationObject.EditDesignerType = typeof(AnnRectangleEditDesigner);
circleAutomationObject.RunDesignerType = typeof(AnnRunDesigner);
circleAutomationObject.ObjectTemplate = new AnnCircleObject();
circleAutomationObject.ToolBarImage = new Bitmap(typeof(Form1), "Resources.Create-a-Custom-Annotation-Circle-Icon.png");
circleAutomationObject.ContextMenu = new Leadtools.Annotations.WinForms.ObjectContextMenu();
annManager.Objects.Add(circleAutomationObject);
annManager.RenderingEngine.Renderers.Add(AnnCircleObject.CircleObjectId, new AnnCircleObjectRenderer(annManager));
}
Run the project by pressing F5, or by selecting Debug -> Start Debugging.
If the steps were followed correctly, the application runs and any of the annotations on the toolbar can be selected to draw on the loaded document. Select the black circle icon, click and drag on the document to add the custom circle annotation. The following image shows the Document Viewer with the annotation toolbar on the right of the viewer.
This tutorial showed how to use the AutomationManager
,AutomationManagerHelper
, AnnAutomation
, and AnnAutomationObject
classes with the DocumentViewer
control to draw and edit automated and custom annotations.