Erratic behavior with Flash’s textWidth property
Just a quick post in case anyone else ever runs into this and manages to find their way to my blog.
I just came across this in a client project I’m working on. I was using a TextField in Flash CS5, and needed to know the width of the actual text inside it for positioning purposes. What I found was that in about 50% of cases, the textWidth property would return zero instead of the strings length in pixels. I tried using autoSize on the TextField and found that it would shorten half of its instances to a single character or less, causing the rest of the line to be invisible.
At first I thought there was something wrong with the font file, but the same happened with Verdana. So I started randomly changing settings, and it turns out that the “anti-alias for readability” setting was causing this. As soon as I changed that setting to “anti-alias for readability” the textfields were being autosized properly, and reported their actual lengths through the textWidth property.
I didn’t really investigate this any further once I found out this workaround. In fact, I needed to use “anti-alias for animation” anyway in my project. Please feel free to comment if this has happened to you, and/or you have more details about this strange little bug.


This is the personal blog of Roy Tanck, designer, geek, entrepreneur and WordPress enthusiast. It's also the home of projects like 
got the same problem right now, the textwidth feature seems to be buggy, its not only the “anti-alias feature, this also happens with text-align center… the recognized textwidth-size seems to be 16/20 to the original :-/
Comment by maemaemae — December 12, 2010 @ 9:47 am
I have ran into this Problem several times and I have always had to call a buddy to come and fix it and he never told me how to fix it. So now I am looking forward to it happening again so i can call him to come over and when he gets there i will fix it in front of him. Thank you for the help!!
P.S. I may take the liberty and time to investigate this a little futher with adobe support. And i will relay anymore information that i find back to you.
Comment by Baby Gates — December 25, 2010 @ 7:30 am
I may take the liberty and time to investigate this a little futher with adobe support. And i will relay anymore information that i find back to you.
Comment by 增高药 — December 31, 2010 @ 4:39 pm
Hi, I have the same problem.. It happens in a browser (most in FF3, sometimes GoogleChrome) not in standalone flashplayer. I dont know what to do.. sometimes multiline textfield dont wrap text, sometimes yes and it is ok – in the same “info box” component, but different instances. Some help? I cant find anything on the net. Thx
Comment by cronello — April 7, 2011 @ 8:00 pm
Thanks a lot! After a few hours of testing, this solution solved the problem!
Comment by Victor — May 9, 2011 @ 5:07 am
I had same when use statics property, set property multiline it ok
Comment by Friv — August 30, 2011 @ 11:57 am
you can get TextField props after TextField rendered just listen TextField object and handle Event.RENDER
Comment by zZeke — April 6, 2012 @ 2:05 pm
If you are getting the TextWidth of a Textfield also make sure you have your TextField scaled to 100%.
It will only return the TextWidth of the font scaled at 100%, no matter what the scale.
Earlier Flash versions have trouble displaying fonts over 90px, so you can maybe try setting the size in AS or using TLF textfields.
Comment by Nunnsey — April 20, 2012 @ 4:42 pm
Hello. I had the same problem. It isn’t important how long the text is. I had long sencentes and it also failed. But I foun a solution. If you are using “anti-alias for readability” you have to do this:
textField.gridFitType = GridFitType.SUBPIXEL;
Now it is working to me.
Comment by Albert Llado — May 16, 2012 @ 4:08 pm