arcgis for flex全国地图天气预报的具体实现过程解析

系统架构是B/S,开发语言是flex，开发工具是myeclise或者flashbuild，通过调用百度提供的在线天气预报web api接口的方式来实现。

采用地图是ArcGIS全国地图，开发接口为arcgis api for flex，但是程序可以拓展api 接口，可以采用其他GIS api，地图数据也可以更换其他地图数据，拓展性比较好。

先谈谈主界面的布局，只是简单的设计了大概的布局，如下：



首先是两行，第一行是标题；第二行再分为两列，第一列是用来天气预报查询以及显示查询的结果，第二列用来显示全国地图。

贴上界面布局的代码：

<s:layout>
<s:VerticalLayout gap="0"/>
</s:layout>
<s:BorderContainer width="100%" backgroundColor="#D7D7D7">
<s:layout>
<s:VerticalLayout paddingBottom="7"
paddingLeft="10"
paddingRight="10"
paddingTop="7"/>
</s:layout>
<s:RichText width="100%">
flex for arcgis----天气预报专题
</s:RichText>
</s:BorderContainer>
<s:HGroup width="100%" height="100%"
paddingLeft="1"
paddingTop="1">
<s:Group width="30%" height="100%" >
<s:Rect width="100%" height="100%">
<s:stroke>
<s:SolidColorStroke color="0xCECECE"/>
</s:stroke>
</s:Rect>
<s:VGroup width="100%" height="100%" horizontalAlign="center">
<s:HGroup horizontalAlign="center" width="100%" paddingTop="10">
<s:Label text="城市名称:" paddingTop="4"/>
<s:TextInput id="txt_userName" text="广州"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Button label="查询" id="btn_login"/>
<s:Button label="查询所有" click="all_clickHandler(event)"/>
</s:HGroup>
<s:Line width="100%">
<s:stroke>
<s:SolidColorStroke color="0xCECECE" weight="1"/>
</s:stroke>
</s:Line>
<s:VGroup width="100%" height="100%" horizontalAlign="center" id="hidepanel" visible="false">
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="星期:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="date1"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="温度:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="temperature1"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="白天:" paddingTop="4"/>
<s:Image id="dayimg1" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="黑夜:" paddingTop="4"/>
<s:Image id="nightimg1" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="气候:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="weather1"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="风向:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="wind1"/>
</s:HGroup>
<s:Line width="100%">
<s:stroke>
<s:SolidColorStroke color="0xCECECE" weight="1"/>
</s:stroke>
</s:Line>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="星期:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="date2"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="温度:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="temperature2"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="白天:" paddingTop="4"/>
<s:Image id="dayimg2" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="黑夜:" paddingTop="4"/>
<s:Image id="nightimg2" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="气候:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="weather2"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="风向:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="wind2"/>
</s:HGroup>
<s:Line width="100%">
<s:stroke>
<s:SolidColorStroke color="0xCECECE" weight="1"/>
</s:stroke>
</s:Line>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="星期:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="date3"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="温度:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="temperature3"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="白天:" paddingTop="4"/>
<s:Image id="dayimg3" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="黑夜:" paddingTop="4"/>
<s:Image id="nightimg3" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="气候:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="weather3"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="风向:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="wind3"/>
</s:HGroup>
<s:Line width="100%">
<s:stroke>
<s:SolidColorStroke color="0xCECECE" weight="1"/>
</s:stroke>
</s:Line>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="星期:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="date4"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="温度:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="temperature4"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="白天:" paddingTop="4"/>
<s:Image id="dayimg4" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="黑夜:" paddingTop="4"/>
<s:Image id="nightimg4" width="25" height="15"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="气候:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="weather4"/>
</s:HGroup>
<s:HGroup horizontalAlign="center" width="100%">
<s:Label text="风向:" paddingTop="4"/>
<s:Label text="" paddingTop="4" id="wind4"/>
</s:HGroup>
</s:VGroup>
<s:Label width="100%"
paddingBottom="0"
text="地理位置: {mapCoordX.toFixed(4)},{mapCoordY.toFixed(4)}"/>
</s:VGroup>
</s:Group>
<esri:Map id="myMap" wrapAround180="true">
<esri:extent>
<esri:Extent xmin="71.6184779133381" ymin="29.726061424023065" xmax="135.50700591988112" ymax="54.94834808582403">
<esri:SpatialReference wkid="4326"/>
</esri:Extent>
</esri:extent>
<esri:infoWindowContent>
<s:TextArea id="myTextArea"
width="250" height="75"/>
</esri:infoWindowContent>
<esri:ArcGISDynamicMapServiceLayer url="http://localhost:6080/arcgis/rest/services/weather/MapServer"/>
<esri:GraphicsLayer id="myGraphicsLayer"/>
</esri:Map>
</s:HGroup>

红色背景的url是地图发布的服务，调用显示全国地图。后台的核心实现：

<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
<s:HTTPService id="httpSer" method="POST">
</s:HTTPService>
<esri:PictureMarkerSymbol id="sfs"/>
<!-- <esri:PictureMarkerSymbol id="sfs1"/>-->
<!-- Layer with US States -->
<esri:QueryTask id="queryTask" url="http://localhost:6080/arcgis/rest/services/weather/MapServer/0"/>
<esri:Query id="query"
outSpatialReference="{myMap.spatialReference}"
returnGeometry="true"
text="{str}">
<esri:outFields>
<fx:String>Name</fx:String>
<fx:String>X</fx:String>
<fx:String>Y</fx:String>
</esri:outFields>
</esri:Query>
</fx:Declarations>

httpSer是声明HTTPService，因为天气预报是调用在线的http形式来实现的；queryTask是用来query查询的条件设置的，作用是为了每个城市的天气预报图标定位在地图上显示，url是指定用哪个图层来进行query查询。

程序运行时候显示的是全国城市的天气预报图标以及信息，所以在初始化时候定义并调用CityCodeDB.xml文件来获取所有的城市名称。

public const xmlUrl:String = "CityCodeDB.xml";

初始化函数：

private function init():void{

getallcityinfo();//获取所有的城市信息
}

/*
* 获取所有城市信息以及相关的天气预报信息
*/
private function getallcityinfo():void{
myGraphicsLayer.clear();
//HTTPService，为了监听初始化时候加载所有的城市天气预报，从配置文件xml获取所有的城市信息
var service:HTTPService = new HTTPService();
service.url = xmlUrl;
service.addEventListener(ResultEvent.RESULT, resultHandler);
service.send();
}

private function resultHandler(event:ResultEvent):void{
citys = event.result.CityCode.City; //获取到所有的配置文件城市名称集合
var service:HTTPService = new HTTPService();
service.addEventListener(ResultEvent.RESULT, cityresultHandler);//为了监听具体的每个城市天气预报信息
for(var i:int;i<citys.length;i++){
str=citys[i].Name;
var params:URLVariables = new URLVariables();
params.name =encodeURIComponent(citys[i].Name); //编码
service.url = "http://api.map.baidu.com/telematics/v3/weather?location="+ params.name+ "&ak=YknGmxIoPugT7YrNrG955YLS";//调用百度提供天气预报的api接口
service.send();
}

private function cityresultHandler(event:ResultEvent):void{
var weather:Weather = new Weather();//自定义的类，主要是定义跟天气预报信息接口对应的字段，比如温度等
if(event.result.CityWeatherResponse.results){
weather.cityname = event.result.CityWeatherResponse.results.currentCity;//当前的城市名称
weather.date =event.result.CityWeatherResponse.results.weather_data.date; //星期
weather.dayPictureUrl=event.result.CityWeatherResponse.results.weather_data.dayPictureUrl;//白天图标
weather.nightPictureUrl=event.result.CityWeatherResponse.results.weather_data.nightPictureUrl;//黑夜图标
weather.temperature=event.result.CityWeatherResponse.results.weather_data.temperature;//温度
weather.weather=event.result.CityWeatherResponse.results.weather_data.weather;//气候
weather.wind=event.result.CityWeatherResponse.results.weather_data.wind;//风向
query.text = weather.cityname;//为了动态的更新query查询text条件
queryTask.execute(query, new AsyncResponder(onResult, onFault));
function onResult(featureSet:FeatureSet, token:Object = null):void
{

if (featureSet.features.length == 0)
{
Alert.show("地图上没有搜索到相关数据定位");
}
else
{
//动态的改变显示在地图上的图标以及graphic
var sps:PictureMarkerSymbol = new PictureMarkerSymbol();
sps.source = weather.dayPictureUrl[0];
var graphic:Graphic = new Graphic(featureSet.features[0].geometry,sps,null);
graphic.toolTip = "当前城市:"+weather.cityname+"\n"+"星期:" + weather.date[0] + "\n" + "温度:" + weather.temperature[0] +"\n"+"气候:"+weather.weather[0]+"\n"+"风向:"+weather.wind[0];
myGraphicsLayer.add(graphic);

}
}
function onFault(info:Object, token:Object = null):void
{
Alert.show(info.toString());
}

}
else{
myGraphicsLayer.clear();
hidepanel.visible = false;
Alert.show("搜索不到城市相关的天气预报数据");
}
}

到这里全国的城市天气预报信息以及图标都实现了。

下面是查询某个城市的天气预报信息，首先在初始化函数init添加httpservice监听事件：

//监听查询按钮单击事件
btn_login.addEventListener(MouseEvent.CLICK,login);
//加载HTTPService的返回监听，为了监听单个城市查询使用
httpSer.addEventListener(ResultEvent.RESULT,httpSerResultHandler);
httpSer.addEventListener(FaultEvent.FAULT,httpSerFaultHandler);

然后在查询按钮事件添加：

//查询天气预报
private function weather(event:MouseEvent):void{
str = txtcity.text; //文本框输入城市名称值
var params:URLVariables = new URLVariables(); //编码
params.name =encodeURIComponent(txt_userName.text);
httpSer.url = "http://api.map.baidu.com/telematics/v3/weather?location="+ params.name+ "&ak=YknGmxIoPugT7YrNrG955YLShttpSer.send();
}

//返回成功事件
private function httpSerResultHandler(event:ResultEvent):void{
var weather:Weather = new Weather();
if(event.result.CityWeatherResponse.results){
hidepanel.visible = true;
weather.cityname = event.result.CityWeatherResponse.results.currentCity;
weather.date =event.result.CityWeatherResponse.results.weather_data.date;
weather.dayPictureUrl=event.result.CityWeatherResponse.results.weather_data.dayPictureUrl;
weather.nightPictureUrl=event.result.CityWeatherResponse.results.weather_data.nightPictureUrl;
weather.temperature=event.result.CityWeatherResponse.results.weather_data.temperature;
weather.weather=event.result.CityWeatherResponse.results.weather_data.weather;
weather.wind=event.result.CityWeatherResponse.results.weather_data.wind;

date1.text = weather.date[0]; //第一天天气预报详情
temperature1.text = weather.temperature[0];
weather1.text = weather.weather[0];
wind1.text = weather.wind[0];
dayimg1.source = weather.dayPictureUrl[0];
nightimg1.source = weather.nightPictureUrl[0];
date2.text = weather.date[1];//第二天天气预报详情
temperature2.text = weather.temperature[1];
weather2.text = weather.weather[1];
wind2.text = weather.wind[1];
dayimg2.source = weather.dayPictureUrl[1];
nightimg2.source = weather.nightPictureUrl[1];
date3.text = weather.date[2];//第三天天气预报详情
temperature3.text = weather.temperature[2];
weather3.text = weather.weather[2];
wind3.text = weather.wind[2];
dayimg3.source = weather.dayPictureUrl[2];
nightimg3.source = weather.nightPictureUrl[2];
date4.text = weather.date[3];//第四天天气预报详情
temperature4.text = weather.temperature[3];
weather4.text = weather.weather[3];
wind4.text = weather.wind[3];
dayimg4.source = weather.dayPictureUrl[3];
nightimg4.source = weather.nightPictureUrl[3];
// clear the graphics layer
myGraphicsLayer.clear();
queryTask.execute(query, new AsyncResponder(onResult, onFault));
function onResult(featureSet:FeatureSet, token:Object = null):void
{
if (featureSet.features.length == 0)
{
Alert.show("地图上没有搜索到相关数据定位");
}
else
{
sfs.source = weather.dayPictureUrl[0];
var graphic:Graphic = new Graphic(featureSet.features[0].geometry,sfs,null);
graphic.toolTip = "当前城市:"+weather.cityname+"\n"+"星期:" + weather.date[0] + "\n" + "温度:" + weather.temperature[0] +"\n"+"气候:"+weather.weather[0]+"\n"+"风向:"+weather.wind[0];
myGraphicsLayer.add(graphic);
myMap.centerAt(featureSet.features[0].geometry as MapPoint);
myMap.zoomIn();
}
}
function onFault(info:Object, token:Object = null):void
{
Alert.show(info.toString());
}
}
else{
myGraphicsLayer.clear();
hidepanel.visible = false;
Alert.show("搜索不到城市相关的天气预报数据");
}
}
//返回失败事件
private function httpSerFaultHandler(event:FaultEvent):void{
Alert.show(event.fault.message as String,"请求天气预报信息失败提示");
}

到这里，某个城市的天气预报信息查询也实现了。效果图：



备注：

源代码下载：http://download.csdn.net/detail/liguoweioo/8440727

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