Draw Event

The event handler receives an argument of type AnnDrawDesignerEventArgs containing data related to this event. The following AnnDrawDesignerEventArgs properties provide information specific to this event.

Property	Description
Cancel	Gets or sets a value indicating whether the draw operation should be canceled.
Object	Gets the AnnObject that is being drawn.
OperationStatus	Gets the status of the draw operation.

When an object is being drawn, the automation object will hook the object draw designer's AnnDrawDesigner.Draw to this event. Therefore, instead of hooking and unhooking to the various designers draw events, you can simply subscribe to this event once.

This example will show how to stop drawing new line objects.

Start with the AnnAutomationManager example, remove all the code inside the example function (search for the // TODO: add example code here comment) and insert the following code:

Click the example button then try to draw a line object.

• C#
• Visual Basic
• WinRT C#
• WinRT JavaScript
• Silverlight C#
• Silverlight VB

Copy Code  

using Leadtools.Annotations.Automation;
using Leadtools.Annotations.Core;
using Leadtools.Codecs;
using Leadtools.Controls;
using Leadtools.Annotations.Rendering;
using Leadtools.Annotations.WinForms;

[TestMethod]
public void AnnAutomation_Draw()
{
   // Hook to the automation's Draw event
   _automation.Draw += _automation_Draw;
}
void _automation_Draw(object sender, AnnDrawDesignerEventArgs e)
{
   // Check if we are drawing a line and we just started, if so, cancel it
   if (_automation.Manager.CurrentObjectId == AnnObject.LineObjectId &&
      e.OperationStatus == AnnDesignerOperationStatus.Start)
   {
      Debug.WriteLine("Canceling line...");
      e.Cancel = true;
   }
}

using Leadtools.Annotations.Automation;
using Leadtools.Controls;
using Leadtools.Converters;
using Leadtools.Annotations.Core;
using Leadtools.Codecs;

[TestMethod]
public void AnnAutomation_Draw()
{
   // Hook to the automation's Draw event
   _automation.Draw += _automation_Draw;
}
void _automation_Draw(object sender, AnnDrawDesignerEventArgs e)
{
   // Check if we are drawing a line and we just started, if so, cancel it
   if (_automation.Manager.CurrentObjectId == AnnObject.LineObjectId &&
      e.OperationStatus == AnnDesignerOperationStatus.Start)
   {
      Debug.WriteLine("Canceling line...");
      e.Cancel = true;
   }
}

Target Platforms

Reference

AnnAutomation Class
AnnAutomation Members