Recursive iteration through every component instance

问题

I have various custom component instances in my flex app. I want to loop through them recursively and get their instance Ids. The recursive part is very important to me. Can someone tell me what's the best way to do it? I have tried doing this, but it didn't do recursive:

for each (var myItem:* in this.MasterContainer.childDescriptors)
{
   trace(myItem.id);
}

回答1:

This will do it:

private function findControlsRecursive(current:DisplayObjectContainer, controls:ArrayCollection):void
{
    for(var idx:int = 0; idx < current.numChildren; idx++)
    {
        var child:DisplayObject = current.getChildAt(idx);
        controls.addItem(child.name);
        var childContainer:DisplayObjectContainer = child as DisplayObjectContainer;
        if(childContainer)
        {
            findControlsRecursive(childContainer, controls);
        }
    } 
}

public function findControls():ArrayCollection
{
    var controls:ArrayCollection = new ArrayCollection();
    findControlsRecursive(Application.application as DisplayObjectContainer, controls);
    return controls;
}

回答2:

I use this to iterate over all components in several methods, with some methods building up results in the accumulator acc (e.g., writing to a String, keeping a count of all, whatever). Iteration includes component chrome when useRaw is true.

    /**
     * Descends through subcomponents applying function
     */
    public static function visitComponent(component:Object, fn:Function, useRaw:Boolean = false, acc:Object = null):Object {
        var newAcc:Object = fn.call(null, component, acc);

        if (component is mx.core.Container) {
            var kids:mx.core.Container = mx.core.Container(component);
            var childList:IChildList;
            if (useRaw) {
                childList = kids.rawChildren;
            } else {
                childList = kids;
            }
            for (var i:int = 0; i < childList.numChildren; ++i) {
                visitComponent(childList.getChildAt(i), fn, useRaw, newAcc);
            }
        } else if (component is DisplayObjectContainer) {
            var displayObjContainer:DisplayObjectContainer = component as DisplayObjectContainer;
            for (var j:int = 0; j < displayObjContainer.numChildren; ++j) {
                visitComponent(displayObjContainer.getChildAt(j), fn, useRaw, newAcc);
            }               
        }
        return newAcc;
    }

    /**
     * Randomly resets backgroundColor of subcomponents
     */
    public static function colorizeComponent(component:Object):void {
        var fn:Function = function(c:Object, acc:Object):Object {
            if (c is UIComponent) {
                (c as UIComponent).setStyle("backgroundColor", Math.random() * uint.MAX_VALUE);
                (c as UIComponent).setStyle("backgroundAlpha", 0.2);
            }
            return null;
        }

        visitComponent(component, fn);
    }

回答3:

Michael Brewer-Davis' function is more through than this example (handling rawchildren, non-flex components, etc), but there's no need for recursion to traverse a tree:

function toEveryComponentDo(f:Function):void
{
    var component:UIComponent = Application.application;
    var components:Array = component.getChildren();
    f(component);

    while (components.length > 0)
    {
        var childComponents:Array = [];

        for each (component in components)
        {
            f(component);
            if (component is Container)
            {
                childComponents = childComponents.append(Container(component).getChildren());
            }
        }

        components = childComponents;
    }
}

来源：https://stackoverflow.com/questions/1751296/recursive-iteration-through-every-component-instance