actionscript-3 - Flex arraycollection getitemindex 总是返回-1

Question

我遇到了同样的问题。有人可以举个例子解释一下吗？

我的代码是:

var dataList:ArrayCollection = new ArrayCollection([{name:"alauddn"}, {name:"ansari"}]);

private function getItemInd(event:MouseEvent):void{

    var item:Object = new Object();
    item.name = "ansari";
    var ias:int = dataList.getItemIndex(item);
    Alert.show(ias.toString() + ": " + item.name);
}

但它返回“-1:

Answer 1

getItemIndex 不比较 arrayCollection 中的值。问题是 getItemIndex() 方法匹配精确的对象引用，而不是具有匹配属性的对象。

您应该改用这样的解决方案:

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
    xmlns:s="library://ns.adobe.com/flex/spark" 
    xmlns:mx="library://ns.adobe.com/flex/mx" creationComplete="creationCompleteHandler(event)">

    <fx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.controls.Alert;
            import mx.events.FlexEvent;

            public var dataList:ArrayCollection = new ArrayCollection([{name:"alauddn"}, {name:"ansari"}]);

            public function getItemIndexByProperty(array:ArrayCollection, property:String, value:String):Number
            {
                for (var i:Number = 0; i < array.length; i++)
                {
                    var obj:Object = Object(array[i])
                    if (obj[property] == value)
                        return i;
                }
                return -1;

                dataList.getItemIndex();
            }

            protected function creationCompleteHandler(event:FlexEvent):void
            {
                var ias:int = getItemIndexByProperty(dataList, "name", "ansari");
                Alert.show(ias.toString() + " : " + dataList.getItemAt(ias).name);
            }

        ]]>
    </fx:Script>

</s:WindowedApplication>