arcgis api for flex 高级主题（二）自定义控件的开发

arcgis api for flex 高级主题（二）自定义控件的开发
arcgis api for flex 本身只提供了Navigation和ScaleBar两个控件，并且api中
对如何开发自定义的控件做详细的描述（也可能有，是我没找到）、
下面就介绍一下我的方法。以实现一个能在地图上动态显示当前鼠标经纬度的控
件。
1 定义控件类，集成UIComponent ，实现IMapAware接口
2 重载createChildren函数
3 实现public function set map(map:Map) : void 函数
4 添加自己的功能代码

Code
package com.esri
{
  import com.esri.ags.*;
     import com.esri.ags.events.*;
     import com.esri.ags.geometry.MapPoint;
     import com.esri.ags.utils.*;
  import flash.display.*;
  import flash.events.MouseEvent;
  import flash.filters.*;
  import flash.text.*;
  import flash.geom.Point;
  import mx.core.*;
  import mx.events.*;
public class ESRIStatusBar extends UIComponent implements
IMapAware
{
  private var m_map:Map;
   private var m_stateLabel:TextField;
  public function ESRIStatusBar()
  {
   m_stateLabel = new TextField();
   m_stateLabel.width = 152;
  }
        override protected function updateDisplayList(log:Number,
pow:Number) : void
        {
           super.updateDisplayList(log, pow);
            return;
        }// end function
  override protected function createChildren() : void
        {
            super.createChildren();

        var pnt:Point  = new Point;
        if(m_map.loaded)
        {
   var mapPnt:MapPoint = new MapPoint
(m_map.extent.xmax,m_map.extent.ymin);
   pnt = m_map.toScreen(mapPnt);
    m_stateLabel.x = pnt.x-150;
            m_stateLabel.y = pnt.y-16;
        }



            addChild(m_stateLabel);
            return;
        }// end function
     private function mouseMoveHandler
(event:MouseEvent):void
     {
      if(m_map)
      {
       if(m_map.loaded)
       {
        var mapPoint : MapPoint =
m_map.toMapFromStage(event.stageX, event.stageY);
        m_stateLabel.text =
"x="+mapPoint.x.toString()+" , y="+mapPoint.y.toString();
       }
      }
     }
     private function extentChangeHandler
(event:ExtentEvent):void
     {
      var pnt:Point  = new Point;
   var mapPnt:MapPoint = new MapPoint
(m_map.extent.xmax,m_map.extent.ymin);
   pnt = m_map.toScreen(mapPnt);

            m_stateLabel.x = pnt.x-150;
            m_stateLabel.y = pnt.y-16;
     }
        public function set map(map:Map) : void
        {
            m_map = map;
            m_map.addEventListener
(MouseEvent.MOUSE_MOVE,mouseMoveHandler);
            m_map.addEventListener(ExtentEvent.EXTENT_CHANGE,
extentChangeHandler);
        }// end function
}
}

把这个控件添加到map上
var statusBar:ESRIStatusBar = new ESRIStatusBar();
IMapAware(statusBar).map = EsriMap;
EsriMap.addChild(statusBar);
放代码

Code
<?xml version="1.0" encoding="utf-8"?>
<mx:Application
    xmlns:mx="http://www.adobe.com/2006/mxml"
    xmlns:esri="http://www.esri.com/2008/ags"
    styleName="plain" >
    <mx:Script>
     <![CDATA[
       import com.esri.*;
   import com.esri.ags.*;
      private function EsriMapCreateComplete():void
      {
       var statusBar:ESRIStatusBar = new
ESRIStatusBar();
             IMapAware(statusBar).map = EsriMap;
             EsriMap.addChild(statusBar);
      }
     ]]>
    </mx:Script>
    <esri:Map crosshairVisible="true" id="EsriMap"
creationComplete="EsriMapCreateComplete()">
        <esri:ArcGISTiledMapServiceLayer

url="http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap
_World_2D/MapServer" />
    </esri:Map>
</mx:Application>

本文转自温景良(Jason)博客园博客，原文链接：http://www.cnblogs.com/wenjl520/archive/2009/06/02/1494586.html，如需转载请自行联系原作者

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