This tutorial demonstrates how to create a WinForms C# application to create a custom annotation using the LEADTOOLS SDK.
Overview | |
---|---|
Summary | This tutorial demonstrates how to use LEADTOOLS custom annotation technology in a C# WinForms Application. |
Completion Time | 45 minutes |
Visual Studio Project | Download tutorial project (13 KB) |
Platform | WinForms C# Application |
IDE | Visual Studio 2017, 2019 |
Development License | Download LEADTOOLS |
Try it in another language |
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Before working on the Create a Custom Annotation - WinForms C# tutorial, get familiar with the basic steps of creating a project by reviewing the Add References and Set a License tutorial.
Create a new C# Windows Winforms project, and add the below necessary LEADTOOLS references.
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 following references are needed:
If using NuGet references, this tutorial will require the following NuGet packages:
Leadtools.Annotations.WinForms
Leadtools.Viewer.Controls.WinForms
If local DLL references are used, the following DLLs are needed. The DLLs are located at <INSTALL_DIR>\LEADTOOLS21\Bin\Dotnet4\x64
:
Leadtools.dll
Leadtools.Annotations.Automation.dll
Leadtools.Annotations.Designers.dll
Leadtools.Annotations.Engine.dll
Leadtools.Annotations.Rendering.WinForms.dll
Leadtools.Annotations.WinForms.dll
Leadtools.Codecs.dll
Leadtools.Codecs.Cmp.dll
Leadtools.Controls.WinForms.dll
Leadtools.Drawing.dll
Leadtools.WinForms.CommonDialogs.File.dll
For a complete list of which Codec DLLs are required for specific formats, refer to File Format Support.
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 Setting a Runtime License.
There are two types of runtime licenses:
Note
Adding LEADTOOLS NuGet and local references and setting a license are covered in more detail in Add References and Set a License.
With the project created, the references added, and the license set, coding can begin. Right-click on Form1.cs
in the Solution Explorer, and select View Code to bring up the code behind the form. Add the below code in the Using block and declare global members.
// Using block at the top
using System;
using System.Drawing;
using System.Windows.Forms;
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Controls;
using Leadtools.Annotations.Engine;
using Leadtools.Annotations.Automation;
using Leadtools.Annotations.Designers;
using Leadtools.Annotations.Rendering;
using Leadtools.Annotations.WinForms;
// Declare these global members
private ImageViewer imageViewer;
private RasterCodecs codecs;
private AutomationInteractiveMode annInteractiveMode;
private IAnnAutomationControl automationControl;
private AnnAutomationManager annManager;
private AnnAutomation annAutomation;
In the Solution Explorer, double-click Form1.cs
to display it in the designer, and click on the Events icon in the Properties Windows. Then, double-click the Load event to create an event handler if one does not already exist.
Add the following code inside the Form1_Load
event handler to initialize the ImageViewer, create a new blank RasterImage, and set it in the viewer.
private void Form1_Load(object sender, EventArgs e)
{
// Initialize the imageViewer object
imageViewer = new ImageViewer();
imageViewer.Dock = DockStyle.Fill;
imageViewer.BackColor = Color.DarkGray;
Controls.Add(imageViewer);
imageViewer.BringToFront();
// Create a plain white background to draw on
imageViewer.Image = RasterImage.Create(1000, 1000, 24, 96, RasterColor.White);
// Initialize the codecs object.
codecs = new RasterCodecs();
}
In the Solution Explorer, drop down the Properties tab, and double-click Resources.resx.
Click Add Resource and then click Add Existing File....
Download the Circle Icon PNG image below and browse to the location 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 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 a new method, name it InitAnnotations()
, and call the new method inside the Form1_Load
event handler below imageViewer.BringToFront()
.
private void Form1_Load(object sender, EventArgs e)
{
// Initialize the imageViewer object
imageViewer = new ImageViewer();
imageViewer.Dock = DockStyle.Fill;
imageViewer.BackColor = Color.DarkGray;
Controls.Add(imageViewer);
imageViewer.BringToFront();
InitAnnotations();
// Create a plain white background to draw on
imageViewer.Image = RasterImage.Create(1000, 1000, 24, 96, RasterColor.White);
// Initialize the codecs object.
codecs = new RasterCodecs();
}
Add the following code inside the InitAnnotations()
method:
void InitAnnotations()
{
//AnnManager initialization comes first
annManager = new AnnAutomationManager();
annManager.RestrictDesigners = true;
annManager.RenderingEngine = new AnnWinFormsRenderingEngine();
//Create my custom objects
CreateCustomObject(annManager);
//create the helper and toolbar, then add them to the form
AutomationManagerHelper annHelper = new AutomationManagerHelper(annManager);
annHelper.CreateToolBar();
Controls.Add(annHelper.ToolBar);
//create the automation control and attach the viewer to it
automationControl = new ImageViewerAutomationControl();
((ImageViewerAutomationControl)automationControl).ImageViewer = imageViewer;
//initialize the interactive mode and add it to the viewer
annInteractiveMode = new AutomationInteractiveMode();
annInteractiveMode.AutomationControl = automationControl;
imageViewer.InteractiveModes.BeginUpdate();
imageViewer.InteractiveModes.Add(annInteractiveMode);
imageViewer.InteractiveModes.EndUpdate();
//initialize the automation
annAutomation = new AnnAutomation(annManager, automationControl);
//whenever loading a new image, set the new size in the container
imageViewer.ItemChanged += ImageViewer_ItemChanged;
annAutomation.Active = true;
}
private void ImageViewer_ItemChanged(object sender, ImageViewerItemChangedEventArgs e)
{
if (e.Reason == ImageViewerItemChangedReason.Image)
annAutomation.Container.Size = annAutomation.Container.Mapper.SizeToContainerCoordinates(imageViewer.ImageSize.ToLeadSizeD());
}
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 should run and display a blank white RasterImage. To draw the custom circle annotations, click the button on the top left of the form.
This tutorial covered how to create a custom circle annotation using the LEADTOOLS Annotations SDK technology.