I am running the following piece of code:
package {
import fl.controls.Button;
import fl.controls.Label;
import fl.controls.RadioButton;
import fl.controls.RadioButtonGroup;
import flash.display.Sprite;
import flash.events.MouseEvent;
import flash.text.TextFieldAutoSize;
public class RadioButtonExample extends Sprite {
private var j:uint;
private var padding:uint = 10;
private var currHeight:uint = 0;
private var verticalSpacing:uint = 30;
private var rbg:RadioButtonGroup;
private var questionLabel:Label;
private var answerLabel:Label;
private var question:String = "What day is known internationally as Speak Like A Pirate Day?";
private var answers:Array = [ "August 12", "March 4", "September 19", "June 22" ];
public function RadioButtonExample() {
setupQuiz();
}
private function setupQuiz():void {
setupQuestionLabel();
setupRadioButtons();
setupButton();
setupAnswerLabel();
}
private function setupQuestionLabel():void {
questionLabel = new Label();
questionLabel.text = question;
questionLabel.autoSize = TextFieldAutoSize.LEFT;
questionLabel.move(padding, padding + currHeight);
currHeight += verticalSpacing;
addChild(questionLabel);
}
private function setupAnswerLabel():void {
answerLabel = new Label();
answerLabel.text = "";
answerLabel.autoSize = TextFieldAutoSize.LEFT;
answerLabel.move(padding + 120, padding + currHeight);
addChild(answerLabel);
}
private function setupRadioButtons():void {
rbg = new RadioButtonGroup("question1");
createRadioButton(answers[0], rbg);
createRadioButton(answers[1], rbg);
createRadioButton(answers[2], rbg);
createRadioButton(answers[3], rbg);
}
private function setupButton():void {
var b:Button = new Button();
b.move(padding, padding + currHeight);
b.label = "Check Answer";
b.addEventListener(MouseEvent.CLICK, checkAnswer);
addChild(b);
}
private function createRadioButton(rbLabel:String, rbg:RadioButtonGroup):void {
var rb:RadioButton = new RadioButton();
rb.group = rbg;
rb.label = rbLabel;
rb.move(padding, padding + currHeight);
addChild(rb);
currHeight += verticalSpacing;
}
private function checkAnswer(e:MouseEvent):void {
if (rbg.selection == null) {
return;
}
var resultStr:String = (rbg.selection.label == answers[2]) ? "Correct" : "Incorrect";
answerLabel.text = resultStr;
}
}
}
This is from Adobe Livedocs. http://www.adobe.com/livedocs/flash/9.0/ActionScriptLangRefV3/
I have added a Radiobutton to stage and then deleted it so that its there in the library.
However I am getting the following error
TypeError: Error #2007: Parameter child must be non-null.
at flash.display::DisplayObjectContainer/addChildAt()
at fl.controls::BaseButton/fl.controls:BaseButton::drawBackground()
at fl.controls::LabelButton/fl.controls:LabelButton::draw()
at fl.controls::Button/fl.controls:Button::draw()
at fl.core::UIComponent/::callLaterDispatcher()
Can anyone tell me what is going on and how to remove this error.