createFromCanvas Method

Summary

Creates a new item from an HTML5 Canvas Element.

Syntax

JavaScript Syntax
createFromCanvas = function(canvas, resolution) 
TypeScript Syntax
static createFromCanvas(canvas: HTMLCanvasElement, resolution: LeadSizeD): ImageViewerItem; 

Parameters

canvas

Source HTML5 Canvas Element.

resolution

The resolution to use for the image in dots/inch (DPI). A value of 0,0 or Empty means to use the default image resolution of 96 pixels.

Return Value

The newly created item, if successful.

Remarks

This method allows you to quickly create an item from an HTML5 Canvas Element. It is the equivalent of the following code:

var item = new lt.Controls.ImageViewerItem(); 
item.canvas = canvas; 
item.resolution = resolution; // Optional 

Use CreateFromImage to create an item from an HTML Image Element. CreateFromElement can also be used as a shortcut for either CreateFromImage or CreateFromCanvas. Passing a valid HTML Image Element to CreateFromElement will create an ImageViewerItem with the Image property set, just as it does with CreateFromImage. Similarly, passing a valid HTML5 Canvas Element to CreateFromElement will create an ImageViewerItem with the Canvas property set, just as it does with CreateFromCanvas. The item can have a value in only one of Image, Element or Canvas. Setting one value will automatically delete the values of the others.

The item is not added to an ImageViewer using this method. You should use the Items collection to add or insert the item before it can be displayed. If an ImageViewer instance exists at the time this method is called, consider using AddFromCanvas, AddFromElement, InsertFromCanvas, or InsertFromElement instead.

Requirements

Target Platforms

Help Version 19.0.2017.10.18
Products | Support | Contact Us | Copyright Notices
© 1991-2017 LEAD Technologies, Inc. All Rights Reserved.

Leadtools.Controls Assembly