Flex坐标系统及转换 - Xiang - CSDN博客

2009-11-01 20:51:48 作者：lekaihuai 来源： 浏览次数：0 网友评论 0 条

 flash和flex针对不同的目的，提供了3种不同的坐标系

          全局的就是(stage级别的)

          本地坐标系（组件级别的）

          内容坐标系（相对于本地坐标系说的）

    这些坐标系的点是可以转换的，并且有相应的方法，看来adobe想得挺周到。我们一个一个的说一下

    全局

           这个坐标系的原点在整个flash舞台的左上角，MouseEvent实例的stageX,stageY就是这个坐标系中的值，

    本地

        坐标原点是相对的组件的左上角，MouseEvent中的localX,localY就是相对这个坐标系说的，

    内容

        这个东西比较抽象了UIComponent类实例的contentMouseX  和 contentMouseY 就是了，这个主要针对有滚动条的组件说的，有滚动条了，内容肯定不少，内容所占的区域的坐标就是这个坐标系了。

下面有个官方的图说明了三个坐标系的关系及位置：

坐标转换还有现成的方法

下面是一个小例子

<?xml version="1.0"?> <!-- containers\intro\MousePosition.mxml --> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" backgroundColor="white"> <mx:Script> <!--[CDATA[ import mx.controls.Alert; // Handle the mouseDown event generated // by clicking in the application. private function handleMouseDown(event:MouseEvent):void { // Convert the mouse position to global coordinates. // The localX and localY properties of the mouse event contain // the coordinates at which the event occurred relative to the // event target, typically one of the // colored internal Canvas controls. // A production version of this example could use the stageX // and stageY properties, which use the global coordinates, // and avoid this step. // This example uses the localX and localY properties only to // illustrate conversion between different frames of reference. var pt:Point = new Point(event.localX, event.localY); pt = event.target.localToGlobal(pt); // Convert the global coordinates to the content coordinates // inside the outer c1 Canvas control. pt = c1.globalToContent(pt); // Figure out which quadrant was clicked. var whichColor:String = "border area"; if (pt.x < 150) { if (pt.y < 150) whichColor = "red"; else whichColor = "blue"; } else { if (pt.y < 150) whichColor = "green"; else whichColor = "magenta"; } Alert.show("You clicked on the " + whichColor); } ]]--> </mx:Script> <!-- Canvas container with four child Canvas containers --> <mx:Canvas id="c1" borderStyle="none" width="300" height="300" mouseDown="handleMouseDown(event);"> <mx:Canvas width="150" height="150" x="0" y="0" backgroundColor="red"> <mx:Button label="I'm in Red"/> </mx:Canvas> <mx:Canvas width="150" height="150" x="150" y="0" backgroundColor="green"> <mx:Button label="I'm in Green"/> </mx:Canvas> <mx:Canvas width="150" height="150" x="0" y="150" backgroundColor="blue"> <mx:Button label="I'm in Blue"/> </mx:Canvas> <mx:Canvas width="150" height="150" x="150" y="150" backgroundColor="magenta"> <mx:Button label="I'm in Magenta"/> </mx:Canvas> </mx:Canvas> </mx:Application>