我正在使用arrayCollection字符串填充dropDownList.我希望下拉列表控件的宽度与数组集合中最长字符串的大小(以像素为单位)匹配.我面临的问题是:集合中字符串的字体宽度不同,例如: ‘W’看起来比’l’宽.所以我估计一个字符的宽度是8像素,但这不是很整洁.如果遇到具有许多“W”和“M”的字符串,则估计是错误的.所以我想要精确的字符串像素宽度.如何获得字符串的确切长度(以像素为单位)?
我的解决方案是将所有字符估计为8像素宽,如下所示:
public function populateDropDownList():void{ var array:Array = new Array("o","two","three four five six seven eight wwww"); var sampleArrayCollection:ArrayCollection = new ArrayCollection(array); var customDropDownList:DropDownList = new DropDownList(); customDropDownList.dataProvider=sampleArrayCollection; customDropDownList.prompt="Select ..."; customDropDownList.labelField="Answer Options:"; //calculating the max width var componentWidth=10; //default for each(var answerText in array){ Alert.show("Txt size: "+ answerText.length + " pixels: " + answerText.length*9); if(answerText.length * 8 > componentWidth){ componentWidth=answerText.length * 8; } } customDropDownList.width=componentWidth; answers.addChild(customDropDownList); }
任何想法或解决方案都很受重视.
谢谢
解决方法
要获得更准确的度量,可以使用字符串填充TextField,然后测量该TextField文本的宽度.
码:
function measureString(str:String,format:TextFormat):Rectangle { var textField:TextField = new TextField(); textField.defaultTextFormat = format; textField.text = str; return new Rectangle(0,textField.textWidth,textField.textHeight); }
用法:
var format:TextFormat = new TextFormat(); format.font = "Times New Roman"; format.size = 16; var strings:Array = [ "a","giraffe","foo","!" ]; var calculatedWidth:Number = 50; // Set this to minimum width to start with for each (var str:String in strings) { var stringWidth:Number = measureString(str,format).width; if (stringWidth > calculatedWidth) { calculatedWidth = stringWidth; } } trace(calculatedWidth);