Calculating Text Width In ActionScript And Flex

问题:

I'm trying to calculate how WIDE to make my button, based on the text that it will contain, and when I try to google for how to calcuate something as simplistic as the WIDTH OF SOME TEXT, I go cross-eyed just trying to wade through apparently nonsensical esoteric counter-intuitive voodoo. Can anyone out there help simplify for me how I would write a function like this:

public function HowWideWouldThisTextBeIfItWereInThisButton(Text:String,Container:Button):int {
 ...
}

Thanks in advance.

回答1:

So long as you're in a UIComponent, you can use the measureText function.

public function howWideWouldThisTextBeIfItWereInThisButton(text:String,container:Button):int {
   var lineMetrics:TextLineMetrics = container.measureText(text);
   return lineMetrics.width;      
}

That being said, the flex button component should automatically size to the width of the text, if you don't set a width on it. That way if you need the text width, you can just call use the textWidth property.

回答2:

This works any format, size, font type. Don't forget properties "autoSize" and "wordWrap"!

var tf:TextField = new TextField();
addChild(tf);
tf.autoSize = TextFieldAutoSize.LEFT;
tf.wordWrap = false;
tf.text = "Whatever here";
tf.width = tf.textWidth + 4; // add 2 pixels-gutters left & right

Your button will need to be "tf.width" wide...

回答3:

Here's how you do it in Spark:

I've modified - simplified - his example a bit here:

var textMetrics:TextLineMetrics = label.measureText( label.text );  
var textWidth:int = textMetrics.width; 

回答4:

Here's a way that works also:

var tempText:Text = new Text();
tempText.regenerateStyleCache(false);
var textWidth:int = tempText.measureText(*yourstring*).width;

回答5:

as I think, textField.textWidth construction works fine... until you change the font size. It seems it calculates width based on 12px font. So, if you have embedded font and global styling you can try fast solution:

var realWidth = myLabel.textField.textWidth * (fontSize / 12);

I've tried this on long and short strings and the result is correct.

回答6:

Joshua, it really helps to be clear. Are you talking TextField, MX Label, Spark Label, RichText, etc? Different text components use different text engines, such as FTE and TLF and may have different solutions. I certainly wish Adobe had a good set of utilities or sample code which could predict what the size of font rendered onto the controls would be, before you actually do it. But, the good news is that in certain cases - like, a good old fashioned TextField, you can predict this pretty well. You just make a TextField, set it's textFormat field, auto size method and the text. You should be able to get it's size before adding it anywhere. I don't remember what the order was, but, I remember the order you set those properties matters. If you can't figure out how to do it, I can provide a code example. Now, for the new, "improved", components such as Spark Labels - I'll be buggered if I can find a damn way... spent a number of hours on this and haven't found a way.. or someone who knows a way :P.

回答7:

Following up my comment on quoo's answer, here's the code for same purpose, but just grabbing the width out of a TextField, using TextLineMetrics as well:

    public function mtxtWidth(container:TextField):int {
       var lineMetrics:TextLineMetrics = container.getLineMetrics(0);
       return lineMetrics.width;      
    }

回答8:

Sounds like you could use textWidth