Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
503 views
in Technique[技术] by (71.8m points)

javascript - Does canvas element have "change" event?

Is there a way to attach event handler to a change of a canvas element? I need to fire a function whenever something draws anything on it.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

No, the canvas element does not provide any events, it's just a plain bitmap.

If you really want to do this, hijack all the calls on a context built in your events and then call the original function (which you have copied previously).

My advice:
Do not do the above, it will be slow and hard to maintain. Instead change the design of your application, you could, for one, make custom drawing functions which will abstract the canvas and put in the event stuff there.

This would also have the added benefit of less context.* calls (therefore cleaner code) when doing a lot of drawing.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...