关于类继承发生的问题-优快云博客

本文介绍了一种自定义多选组合框的方法，通过继承MultiSelectComboBox类并设置itemRenderer来实现多选功能。文中详细展示了如何使用ClassFactory创建自定义渲染器，并探讨了不同基类对最终行为的影响。

    public class ChkRenderComboBox extends MultiSelectComboBox
    {
        [Bindable]
        public var rendererInMultiSelectComBox:ClassFactory = new ClassFactory(CheckBox);
        [Bindable]
        private var factory:ClassFactory;
        /**
        * Constructor.
        */
        public function ChkRenderComboBox()
        {
    //        var factory:ClassFactory = new ClassFactory(List);
    //        factory.properties = {allowMultipleSelection:true,itemRenderer:rendererInMultiSelectComBox};
    //        factory.properties.allowMultipleSelection = true;
    //        factory.properties.itemRenderer = rendererInMultiSelectComBox;
            this.addEventListener(FlexEvent.CREATION_COMPLETE,creationCompleteHandler);
//            super.dropdownFactory = factory;
            BindingUtils.bindSetter(updateSelectedValue, this, "selectedItem");
        }

        public function creationCompleteHandler(event:FlexEvent):void
        {
            trace("lllllllllllkkkkkkkkkkkkffffdgghdfjhjjjjjjhhhhhhhhhh");
            factory = new ClassFactory(List);
            factory.properties = {allowMultipleSelection:true,itemRenderer:rendererInMultiSelectComBox};
            dropdownFactory = factory;
            trace("asddddddadasdasdadadsadad"+ObjectUtil.toString(dropdownFactory));
        }

结果：

lllllllllllkkkkkkkkkkkkffffdgghdfjhjjjjjjhhhhhhhhhh
asddddddadasdasdadadsadad(mx.core::ClassFactory)#0
generator = (flex3Lib.controls::MultiSelectList )
properties = (null)

但如果extends ComboBox 的话，结果为：

lllllllllllkkkkkkkkkkkkffffdgghdfjhjjjjjjhhhhhhhhhh
asddddddadasdasdadadsadad(mx.core::ClassFactory)#0
generator = (mx.controls::List )
properties = (Object)#1
    allowMultipleSelection = true
    itemRenderer = (mx.core::ClassFactory)#2
      generator = (mx.controls::CheckBox)
      properties = (null)

这可能与MultiSelectComboBox 的构造函数的写法有关。