Flex:特殊外壳列表或菜单中的项目? [英] Flex: Special-casing an item in a list or menu?

问题描述

我发现将下拉菜单中的第一项(即 Menu 的一个实例)设为特殊情况通常很有用.例如，如果我想从网络服务提供的列表中选择一种颜色:

I've found it's often useful to special case the first item in a drop-down menu (ie, an instance of Menu). For example, if I want to pick a color from the list provided by a web service:

<mx:PopUpMenuButton id="colorSelelector"
    dataProvider="{colorsService.lastResult}" />

我可能还需要一个特殊情况，即输入新颜色"，允许用户输入不在列表中的新颜色的 RGB 值.例如:

I might also want a special-case, which is "enter a new color", allowing the user to enter the RGB values for a new color which isn't in the list. For example:

var newColor = { label: "Enter a new color", rgb: null };

然后用于:

<mx:PopUpMenuButton id="colorSelelector"
    dataProvider="{colorsService.lastResult}"
    lastOption="{newColor}" />

那么，除了更改我从服务中返回的列表之外，还有什么更好的方法可以做到这一点?

So, apart from changing the list I get back from the service, is there any better way to do this?

(而且只是先发制人的评论:这是一种简化……我实际上并不是在尝试制作颜色选择列表)

(and just a preemptive comment: this is a simplification… I'm not actually trying to make a color-picking-list)

推荐答案

所以，除了改变我得到的列表从服务回来，有没有更好的方法来做到这一点?

So, apart from changing the list I get back from the service, is there any better way to do this?

这种方法将是最干净的，无需扩展 HTTPService，它会运行良好(但实际上只是改变了您的结果；)):

This approach is going to be the cleanest, without extending HTTPService, which would work well (but is really just altering your result ;) ):

package
{
    import mx.rpc.http.HTTPService;

    public class MyHTTPService extends HTTPService
    {
        public var appendToResult:Object;

        public function MyHTTPService(rootURL:String=null, destination:String=null)
        {
            super(rootURL, destination);
        }

        [Bindable("resultForBinding")]
        override public function get lastResult():Object
        {
            //I know what my type is, Array as an example
            var myResult:Array = operation.lastResult;
            myResult.push( this.appendToResult )
            return myResult;
        }
    }
}

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