ArcGIS.Server.9.3和ArcGIS API for Flex实现GraphicsLayer上画点、线、面（五）

目的：
1.ArcGIS API for Flex实现GraphicsLayer上画点、线、面。
准备工作：
1.这次地图数据就用Esri提供的http://server.arcgisonline.com/ArcGIS/rest/services/NPS_Physical_World_2D/MapServer。
完成后的效果图：

开始：
1.启动Flex Builder3新建工程以及引入ArcGIS API for Flex library的开发包。
2.新建DrawTool.mxml页面，然后在页面上添加esri:Map控件设置esri:ArcGISTiledMapServiceLayer等。
3.和上一篇一样仍旧用mx:ToggleButtonBar来实现功能按钮，mx:ToggleButtonBar需要包含6个按钮分别实现6种不一样的操作，具体代码如下：

 1<mx:ToggleButtonBar iconField="icon"  horizontalCenter="-47" verticalCenter="-151" itemClick="itemClickHandler(event)" toggleOnClick="true">
 2        <mx:dataProvider>
 3        <mx:Array>
 4        <mx:Object icon="{point}" />
 5        <mx:Object icon="{point2}" />
 6        <mx:Object icon="{polyline3}" />
 7        <mx:Object icon="{polyline}" />
 8        <mx:Object icon="{polyline2}" />
 9        <mx:Object icon="{polygon}" />
        <mx:Object icon="{polygon2}" />
        <mx:Object icon="{polygon3}" />
        </mx:Array>
        </mx:dataProvider>
        </mx:ToggleButtonBar>

4.上面的代码中icon对应的图标定义在mx:Script中如下：

 1//图标图片
 2            [Bindable] 
 3            [Embed(source="assets/point.gif")]
 4            public var point:Class; 
 5            
 6            [Bindable] 
 7            [Embed(source="assets/point2.gif")]
 8            public var point2:Class; 
 9            
            [Bindable] 
            [Embed(source="assets/polyline.gif")]
            public var polyline:Class; 
            
            [Bindable] 
            [Embed(source="assets/polyline3.gif")]
            public var polyline3:Class; 
            
            [Bindable] 
            [Embed(source="assets/polyline2.gif")]
            public var polyline2:Class; 
            
            [Bindable] 
            [Embed(source="assets/polygon.gif")]
            public var polygon:Class; 
            
            [Bindable] 
            [Embed(source="assets/polygon2.gif")]
            public var polygon2:Class; 
            
            [Bindable] 
            [Embed(source="assets/polygon3.gif")]
            public var polygon3:Class; 

5.现在要实现在地图上画点、线等就需要esri:GraphicsLayer 的功能，实际上点、线、面都是画在GraphicsLayer的所以需要在Map控件中添加：

<esri:Map id="myMap" extent="{allMap}" logoVisible="false">
        <esri:ArcGISTiledMapServiceLayer url="http://server.arcgisonline.com/ArcGIS/rest/services/NPS_Physical_World_2D/MapServer" />
        <esri:GraphicsLayer id="myGraphicsLayer"/> 
    </esri:Map>

6.要进行绘制功能esri已经提供了esri:Draw这个控件能很方便的实现基本图形的绘制，使用代码如下：

<esri:Draw id="drawToolbar" map="{myMap}" graphicsLayer="{myGraphicsLayer}" />

7.esri:Draw有2个属性一个是要进行画图操作的地图控件，一个是画图的容器GraphicsLayer 。
8.接下来定义一下画出来的点、线、面的显示样式，代码如下：

<esri:SimpleLineSymbol id="sls" style="solid" color="0xFF0000" width="2" alpha="1"/>
<esri:SimpleMarkerSymbol id="sms" style="square" color="0xFF0000" size="10" />
<esri:SimpleFillSymbol id="sfs" style="solid" color="0xFF0000" alpha="0.5"/>

9.上面的sls为线的显示样式；sms为点的显示样式；sfs为面的显示样式，关于样式的定义可以查询一下帮助了有很多的样式等可以实现。
10.最后就是编写功能代码在上面的ToggleButtonBar控件中已经给它添加了一个itemClick="itemClickHandler(event)"，这里就是编写itemClickHandler(event)这个方法的代码：

 1import mx.events.ItemClickEvent;
 2private function itemClickHandler(event:ItemClickEvent):void
 3            {
 4                //设置点样式
 5                drawToolbar.markerSymbol=sms;
 6                //设置线样式
 7                drawToolbar.lineSymbol=sls;
 8                //设置面样式
 9                drawToolbar.fillSymbol=sfs;
                //更加按钮的index值设置不同的绘制操作
                switch(event.index)
                {
                    case 0:
                    {
                        drawToolbar.activate(Draw.MAPPOINT);
                        break;
                    }
                    case 1:
                    {
                        drawToolbar.activate(Draw.MULTIPOINT);
                        break;
                    }
                    case 2:
                    {
                        drawToolbar.activate(Draw.LINE);
                        break;
                    }
                    case 3:
                    {
                        drawToolbar.activate(Draw.POLYLINE);
                        break;
                    }
                    case 4:
                    {
                        drawToolbar.activate(Draw.FREEHAND_POLYLINE);
                        break;
                    }
                    case 5:
                    {
                        drawToolbar.activate(Draw.POLYGON);
                        break;
                    }
                    case 6:
                    {
                        drawToolbar.activate(Draw.FREEHAND_POLYGON);
                        break;
                    }
                    case 7:
                    {
                        drawToolbar.activate(Draw.EXTENT);
                        break;
                    }
                }
            }

11.很简单就完成了这些功能可以运行查看效果。