Legacy Controls NOTICE
This article references our legacy Web Forms Web Viewing controls (WebImageViewer, WebAnnotationViewer, WebThumbnailViewer). It is preserved for archival purposes, but support strongly recommends using our modern HTML5 web controls: WebDocumentViewer, WebDocumentThumbnailer instead)
INFO: WebDocumentViewer Whitepaper - Getting Started With Web Viewing
Main Article Content
Sometimes, it is necessary to abort/cancel the user/interactive creation of
an annotation on our WebAnnotationViewer after it has begun.
For example: a user starts creating a highlight annotation, but drags the
mouse off the control and clicks on a different page in the WebThumbnailViewer;
technically, annotation creation is still occurring back on the previous
page/layer.
Adding a handler for WebThumbnailViewer1.SelectedIndexChanged that will call
WebAnnotationViewer1.CancelCreateAnnotation(); will stop the creation of the
initial annotation without leaving a partial annotation on the existed page.
WebThumbnailViewer1.SelectedIndexChanged = CancelCreation;
function CancelCreation() {
WebAnnotationViewer1.CancelCreateAnnotation();
}
This is also useful when you wish to give the user the option to manually
cancel interactive creation. You can make a simple button with a call to this
will cancel the current creation:
<input type="button" id="btn_CancelAnnotation" value="Cancel"
onclick="WebAnnotationViewer1.CancelCreateAnnotation(); return false;"
/>
(note the use of return false; to keep the button from posting back - this is
important to the proper functioning of our
WebAnnotationViewer/WebThumbnailViewer controls.
NOTE: This article is specifically about our ASP.NET web control:
WebAnnotationViewer. For cancelation of interactive annotation creation in a
WinForms solution using our AnnotateViewer control, please see Q10112 - HOWTO: How can I cancel a call to CreateAnnotation in WinForms apps using AnnotateViewer?
Original Article:
Q10387 - HOWTO: Cancel Creation of Annotations in WebAnnotationViewer control (Legacy Web Controls)