Flex坐标系统及转换

xiaoxiao2025-12-12  4

这些天简单重新玩了一下Flex,感受觉坐标这块挺有意思,下面译一下关于坐标的文档

        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

contentMouseX

返回mouse的内容坐标x值

contentMouseY

返回mouse的内容坐标Y值

contentToGlobal   

将内容坐标转换成全局坐标

contentToLocal 

将内容坐标转换成内容坐标

globalToContent   

将全局的转成内容坐标

globalToLocal 

全局的转成本地的

localToContent

本地到内容坐标

localToGlobal 

本地到全局坐标

 

 

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 coordinate s.             // The localX and localY properties of the mouse event contain             // the coordinate s 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 coordinate s,              // 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 coordinate s to the content coordinate s              // 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>

相关资源:敏捷开发V1.0.pptx
转载请注明原文地址: https://www.6miu.com/read-5040749.html

最新回复(0)