flex 圆形布局

package layouts

{

import mx.core.ILayoutElement;

import spark.layouts.supportClasses.LayoutBase;

public class CircularLayout extends LayoutBase

{

public function CircularLayout()

{

super();

}

override public function updateDisplayList(w:Number,h:Number):void

{

super.updateDisplayList(w,h);

if (!target)

return;

var layoutElement:ILayoutElement;

var count:uint = target.numElements;

trace(count);

var radius : Number = Math.min( target.width/2,target.height/2 ) - 25;

var _x:Number=0;

var _y:Number=0;

var angleRadians:Number=2*Math.PI/count;

var ar:Number=0;

var centerX:Number=target.width/2;

var centerY:Number=target.height/2;

for (var i:int = 0; i < count; i++)

{

layoutElement = target.getElementAt(i);

var width:Number=layoutElement.getLayoutBoundsWidth();

var height:Number=layoutElement.getLayoutBoundsHeight();

_x=Math.sin( ar )*radius+centerX-width/2;

_y=centerY-Math.cos(ar)*radius-height/2;

trace("x:"+_x+" y:"+_y);

trace("width:"+layoutElement.getLayoutBoundsWidth()+" height:"+layoutElement.getLayoutBoundsHeight());

// layoutElement.setLayoutBoundsSize(70,20);

layoutElement.setLayoutBoundsPosition(_x,_y);

ar=ar+angleRadians;

}

}

}

}

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mxml代码：

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<s:BorderContainer x="202" y="144" width="200" height="200">

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<!-- -->

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<s:layout>

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<layouts:CircularLayout />

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</s:layout>

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<s:Button label="Button" width="70" height="20"/>

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<s:Button label="Button" width="70" height="20"/>

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<s:Button label="Button" width="70" height="20"/>

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<s:Button label="Button" width="70" height="20"/>

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<s:Button label="Button" width="70" height="20"/>

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<s:Button label="Button" width="70" height="20"/>

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</s:BorderContainer>

效果: