通过经纬度获取城市yahoo天气预报（最新2013-4-17）

来源：易妖游戏网

原文：http://blog.sina.com.cn/s/blog_87a824440101bqcl.html

注：原来的版本不可以用了，yahoo改了写东西，现在只有通过yql来实现对天气的获取woeid的值，请大家注意看看:改法如下：

原来是 :

#define URL_LOCATION @ "http://where.yahooapis.com/geocode? location=%f+%f&gflags=R&appid=yourappid"

现在是 :

(用宏定义的转义字符，居然在新浪博客显示不出来，只有裁图了，不裁图显示这个： #define URL_LOCATION @" * from geo.placefinder where text="%f,%f" and gflags="R""，晕 )，但这样做还是会出错，解决方法请看下面的： - (void)xmlReadConnect函数

首先声明一下：由于的GPS定位的经纬度有误差，导致你所在的位置的经纬度有偏差，但能确定是在你当前所在的城市，因为我们只要所在城市，再通过城市获取yahoo天气预报，因此只要你在的城市是正确的即可。

Weather.h 文件

#import <UIKit/UIKit.h>

@interface Weather : UIViewController<CLLocationManagerDelegate,NSXMLParserDelegate,NSURLConnectionDelegate,NSURLConnectionDataDelegate>{

CLLocationManager *lma;

NSXMLParser *xmlParser;

NSURLConnection *urlConn;

NSMutableData *webData;

NSURLRequest *request;

}

@property (assign) CLLocationManager *lma;

@property (nonatomic,retain) NSString *getCurrentElement;

@property (nonatomic,retain) NSDictionary *Dic_weathForecast;

@property (nonatomic,retain) NSString *getwoeidValue;

- (void)xmlReadConnect;

-(void)mapLocationPreLoad;

Weather.m 文件

#import "Weather.h"

@implementation Weather

@synthesize lma;

@synthesize getCurrentElement;

@synthesize Dic_weathForecast;

@synthesize getwoeidValue;

#define URL_FORECAST @"http://xml.weather.yahoo.com/forecastrss?w=%@&u=%@"

//以前的版本用：

//#define URL_LOCATION @"http://where.yahooapis.com/geocode?location=%f+%f&gflags=R&appid=yourappid"

//2013-4-17 现在用yql, 这里用到宏定义的转意字符 \ ，这里只有裁图了

//被新浪拦截了转义字符后是这样的，#define URL_LOCATION @" * from geo.placefinder where text="%f,%f" and gflags="R"" ，但这样做还是会出错，原因请看下面的 - (void)xmlReadConnect函数方法

-(void)mapLocationPreLoad{

lma = [[CLLocationManager alloc] init];

lma.delegate = self;

lma.desiredAccuracy = kCLLocationAccuracyBest;

lma.distanceFilter = 5;

}

- (void)xmlReadConnect

{

//被注释的部分，是之前的版本

//CLLocationCoordinate2D coordinate = [lm.location coordinate];

//NSString *URLString = [NSStringstringWithFormat:URL_LOCATION,coordinate.latitude, coordinate.longitude];//通过经纬度获取城市的woeid

//request = [NSURLRequest requestWithURL:[NSURLURLWithString:URLString]cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

// urlConn = [[NSURLConnection alloc] initWithRequest:requestdelegate:self];

//if (urlConn)

//{

// webData = [[NSMutableData alloc] init];

// }

//（2013-4-17改成这样了）改动之后注意：首先你要启动你的GPS，获取你所在地的经纬度，如果经纬度获取成功之后，然后通过经纬度获取woeid，之前的方法现在用不了了，现在yahoo通过经纬度获取woeid的方法改了，需要用yql来获取，yql的使用可以参考yahoo的yql用法。

//URL编码中表示空格符 , 表示双引号，不懂的请自己去查询 URL编码手册啊

//本来URLString = @" * from geo.placefinder where text="%f,%f" and gflags="R"" 就可以了，但这样写会出错，因为这写%f参数和双引号的原因，所以要用URL编码来处理，方法如下：

//改动之后是：

//上面的方法只有通过三个字连接起来的

//这里只能用插图了，不好意思，因为新浪博客会拦截URL编码

}

- (void)viewDidLoad

{

[self mapLocationPreLoad];

[self xmlReadConnect];

}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response

{

[webData setLength:0];

}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data

{

[webData appendData:data];

}

- (void)connection:(NSURLConnection *)connection didCancelAuthenticationChallenge:(NSURLAuthenticationChallenge*)challenge

{

}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error

{

[urlConn release];

}

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge*)challenge

{

}

- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge

{

}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection

{

NSString *xmlString = [[[NSString alloc] initWithBytes:[webDatamutableBytes] length:[webData length] encoding:NSUTF8StringEncoding]retain];

if (xmlParser)

{

[xmlParser release];

}

xmlParser = [[NSXMLParser alloc] initWithData:webData];

[xmlParser setDelegate:self];

[xmlParser setShouldResolveExternalEntities:YES];

[xmlParser parse];

}

bool flagNow = YES;

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString*)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict

{

getCurrentElement = elementName;

[getCurrentElement retain];

if ([elementName isEqualToString:@"yweather:condition"])//获取天气的信息

{

self.Dic_weathCondition = attributeDict;

currentWeatherValue = [[[NSString stringWithFormat:@"%@",[attributeDict objectForKey:@"text"]] uppercaseString] retain];

currentTempValue = [[[NSString stringWithFormat:@"%@",[attributeDict objectForKey:@"temp"]] uppercaseString] retain];

NSLog(@"currentWeatherValue = %@, currentTempValue = %@",[attributeDict objectForKey:@"text"],[attributeDict objectForKey:@"temp"]);

}

if ([elementName isEqualToString:@"yweather:forecast"])

{

if (flagNow == YES)

{

self.Dic_weathForecast = attributeDict;

flagNow = NO;

NSString *stringWeather = [NSStringstringWithFormat:@"%@",[attributeDict objectForKey:@"text"]];

NSString *stringHighTemp = [NSStringstringWithFormat:@"%@",[attributeDict objectForKey:@"high"]];

NSString *stringLowTemp = [NSStringstringWithFormat:@"%@",[attributeDict objectForKey:@"low"]];

NSLog(@"stringWeather= %@,stringHighTemp = %@,stringLowTemp = %@",stringWeather,stringHighTemp,stringLowTemp);

return ;

}

else

{

flagNow = YES;

}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString*)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName

{

if (qName)

{

elementName = qName;

}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString*)string

{

if ([[getCurrentElement lowercaseString]isEqualToString:@"woeid"])

{

getwoeidValue = string; //获取woeid的值

if (getwoeidValue.length>0)

{

NSString *URLString = [NSStringstringWithFormat:URL_FORECAST,getwoeidValue, @"c"];

request = [NSURLRequest requestWithURL:[NSURLURLWithString:URLString]cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];

urlConn = [[NSURLConnection alloc]initWithRequest:request delegate:self];

if (urlConn)

{

webData = [[NSMutableData alloc] init];

}

[getwoeidValue retain];

}

@end

//内存泄漏问题大家自己改了，我只提高实现获取yahoo天气方法

因篇幅问题不能全部显示，请点此查看更多更全内容

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通过经纬度获取城市yahoo天气预报（最新2013-4-17）