在實現中用到的一些方法，再此文中可以找到： 完美解析Google weather API,得到天氣信息并顯示 ：http://blog.csdn.net/zyc851224/article/details/7383689

1、首先要明白我們需要解析XML文件，而且我們使用的是SAX的方式。第一步我們可以基于single-view來創建一個工程，（這里使用的是xcode4.2）,添加代理：

#import <UIKit/UIKit.h> @class ViewController; @interface AppDelegate : UIResponder <UIApplicationDelegate,NSXMLParserDelegate>//添加XMLParser代理 @property (strong, nonatomic) UIWindow *window; @property (strong, nonatomic) ViewController *viewController; @end
2、完成后在viewController.h文件中聲明我們需要的各種控件和變量。我是這么聲明的：

#import <UIKit/UIKit.h> @interface ViewController : UIViewController{ //保存解析結果的可變數組 NSMutableArray *arryDataMutable; //NSMutableArray *tempData; //天氣圖片顯示view UIImageView *iocnImage; UIImageView *iconImage1; UIImageView *iconImage2; UIImageView *iconImage3; UIImageView *iconImage4; //UIImageView *iconImage5; //UIImageView *iconImage6; //當日天氣基本信息顯示文本框 IBOutlet UILabel *cityLable; //城市 IBOutlet UILabel *forecast_dateLable;//日期 IBOutlet UILabel *conditionLable; //天氣情況 IBOutlet UILabel *temp_fLable; //華氏溫度 IBOutlet UILabel *temp_cLable; //攝氏溫度 IBOutlet UILabel *humidityLable; //濕度 IBOutlet UILabel *wind_conditionLable; //風信息 //往后幾日天氣信息顯示文本框 IBOutlet UILabel *day_of_weekcLable1; IBOutlet UILabel *day_of_weekcLable2; IBOutlet UILabel *day_of_weekcLable3; IBOutlet UILabel *day_of_weekcLable4; //IBOutlet UILabel *day_of_weekcLable5; //解析出的時間日期顯示文本框 IBOutlet UILabel *datetimeLabel; //可變數組大小存儲變量 int arrySizInt; //UITableView *tableView; } @property (nonatomic, retain)IBOutlet UILabel *cityLable; @property (nonatomic, retain)IBOutlet UILabel *forecast_dateLable; @property (nonatomic, retain)IBOutlet UILabel *conditionLable; @property (nonatomic, retain)IBOutlet UILabel *temp_fLable; @property (nonatomic, retain)IBOutlet UILabel *temp_cLable; @property (nonatomic, retain)IBOutlet UILabel *humidityLable; @property (nonatomic, retain)IBOutlet UILabel *wind_conditionLable; @property(nonatomic ,retain) NSMutableArray *arryDataMutable; @property (nonatomic,retain)IBOutlet UIImageView *iconImage; @property (nonatomic,retain)IBOutlet UIImageView *iconImage1; @property (nonatomic,retain)IBOutlet UIImageView *iconImage2; @property (nonatomic,retain)IBOutlet UIImageView *iconImage3; @property (nonatomic,retain)IBOutlet UIImageView *iconImage4; //@property (nonatomic,retain)IBOutlet UIImageView *iconImage5; //@property (nonatomic,retain)IBOutlet UIImageView *iconImage6; //@property (nonatomic, retain) NSMutableArray *tempData; @property (nonatomic,retain)IBOutlet UILabel *day_of_weekcLable1; @property (nonatomic,retain)IBOutlet UILabel *day_of_weekcLable2; @property (nonatomic,retain)IBOutlet UILabel *day_of_weekcLable3; @property (nonatomic,retain)IBOutlet UILabel *day_of_weekcLable4; //@property (nonatomic,retain)IBOutlet UILabel *day_of_weekcLable5; @property (nonatomic,retain)IBOutlet UILabel *datetimeLabel; @property int arrySizInt; //@property (nonatomic, retain)IBOutlet UITableView *tableView; @end
3、完成后我們在viewController.m文件里進行主要的操作和實現。

首先我們要獲取 api 的地址，我獲取的地址是：

http://www.google.co.uk/ig/api?weather=Beijing，為了便于以后操作，我們定義一個變量來保存城市名稱。

然后再對具體的信息進行解析存儲并顯示，主要代碼如下：

-(IBAction) GetLocalWeather { //位置定位，可在界面設置用戶選擇或者查詢或者輸入來獲取 NSString *location = @"Beijing"; //api地址前綴 NSString *address = @"http://www.google.co.uk/ig/api?weather="; //合成實際的訪問地址 NSString *request = [NSString stringWithFormat:@"%@%@&hl=zh_CN&oe=UTF-8",address,location]; //聲明URL進行地址訪問 NSURL *URL = [NSURL URLWithString:request]; NSError *error; //獲取XML文件，如果編碼格式不是UTF-8，需要對網頁進行轉碼 NSString *XML = [NSString stringWithContentsOfURL:URL encoding:NSUTF8StringEncoding error:&error]; //NSLog(@"XML: %@", XML); /***************使用分段方法對xml前半部分進行解析************/ // 溫度獲取 攝氏 NSString *tempInC = [[[[XML componentsSeparatedByString:@"temp_c data=\""] objectAtIndex:1] componentsSeparatedByString:@"\""] objectAtIndex:0]; // 溫度獲取 華氏 NSString *tempInF = [[[[XML componentsSeparatedByString:@"temp_f data=\""] objectAtIndex:1] componentsSeparatedByString:@"\""] objectAtIndex:0]; // 城市獲取 NSString *city = [[[[XML componentsSeparatedByString:@"postal_code data=\""] objectAtIndex:1] componentsSeparatedByString:@"\""] objectAtIndex:0]; // 日期獲取 NSString *date = [[[[XML componentsSeparatedByString:@"forecast_date data=\""]objectAtIndex:1]componentsSeparatedByString:@"\""]objectAtIndex:0]; // 天氣獲取 NSString *condition = [[[[XML componentsSeparatedByString:@"condition data=\""] objectAtIndex:1] componentsSeparatedByString:@"\""] objectAtIndex:0]; // 濕度獲取 NSString *humidity = [[[[XML componentsSeparatedByString:@"humidity data=\""] objectAtIndex:1] componentsSeparatedByString:@"\""] objectAtIndex:0]; // 風信息獲取 NSString *wind = [[[[XML componentsSeparatedByString:@"wind_condition data=\""] objectAtIndex:1] componentsSeparatedByString:@"\""] objectAtIndex:0]; // 天氣圖片獲取，需要獲取圖片的實際地址，獲取后存放在NSData中 NSString *icon = [[[[XML componentsSeparatedByString:@"icon data=\""]objectAtIndex:1]componentsSeparatedByString:@"\""]objectAtIndex:0]; iconImage.image=nil; NSString* path =[NSString stringWithFormat: @"http://www.google.co.uk%@",icon]; NSURL* url = [NSURL URLWithString:[path stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];//網絡圖片url NSData* data = [NSData dataWithContentsOfURL:url];//獲取網絡圖片數據 arryDataMutable = [[NSMutableArray alloc] init]; //打印輸出 cityLable.text = city; forecast_dateLable.text = date; conditionLable.text = condition; humidityLable.text = humidity; wind_conditionLable.text = wind; temp_fLable.text = tempInF; temp_cLable.text = tempInC; //對圖片進行圓角處理并顯示 CALayer *layer = [iconImage layer]; [layer setMasksToBounds:YES]; [layer setCornerRadius:5.0]; [layer setBorderWidth:1.0]; [layer setBorderColor:[UIColor blackColor].CGColor]; iconImage.image = [[UIImage alloc] initWithData:data];//根據圖片數據流構造image // //TEST NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:URL]; [parser setDelegate:self]; [parser parse]; arrySizInt = [arryDataMutable count]; //NSLog(@"[arryDataMutable count]: %d", arrySizInt); //接下來獲取剩余四天的天氣情況。（谷歌天氣每次只有未來四天的信息） //初始化計數，通過次變量的值來打印輸出未來四天的信息 int counter = 0; //循環開始，這里從1開始，因為可變數組中第0個，是當天的信息，已經解析輸出 for (int i=1; i<arrySizInt; i++) { //NSLog(@"Array: %@", [arryDataMutable objectAtIndex:i]); //獲取數組中的對象，存放在字符串中 NSString *dayStr = [[NSString alloc] initWithString:[arryDataMutable objectAtIndex:i]]; // // if ([dayStr isEqualToString:@"Mon"] || // [dayStr isEqualToString:@"Tue"] || // [dayStr isEqualToString:@"Wed"] || // [dayStr isEqualToString:@"Thu"] || // [dayStr isEqualToString:@"Fri"] || // [dayStr isEqualToString:@"Sat"] || // [dayStr isEqualToString:@"Sun"] ) //判斷獲取的元素是那一天，是需要判斷是否相等即可，并且使用或的運算，只要有一個為真，此表達式即成立 if ([dayStr isEqualToString:@"周一"] || [dayStr isEqualToString:@"周二"] || [dayStr isEqualToString:@"周三"] || [dayStr isEqualToString:@"周四"] || [dayStr isEqualToString:@"周五"] || [dayStr isEqualToString:@"周六"] || [dayStr isEqualToString:@"周日"] ) { NSLog(@"counter: %d", counter); //獲取數組中剩余的三項 //或許最低溫度 NSString *lowStr = [[NSString alloc] initWithString:[arryDataMutable objectAtIndex:(i+1)]]; //獲取最高溫度 NSString *highStr = [[NSString alloc] initWithString:[arryDataMutable objectAtIndex:(i+2)]]; //獲取天氣圖片路徑 NSString *path = [[NSString alloc] initWithString:[arryDataMutable objectAtIndex:(i+3)]]; NSString* iconpath =[NSString stringWithFormat: @"http://www.google.co.uk%@",path]; NSURL* url = [NSURL URLWithString:[iconpath stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];//網絡圖片url NSData* data = [NSData dataWithContentsOfURL:url];//獲取圖片數據 //獲取天氣情況 NSString *conditions = [[NSString alloc] initWithString:[arryDataMutable objectAtIndex:(i+4)]]; //將獲取的信息整理存放 NSString *tempStrToDisp = [NSString stringWithFormat: @"%@\n %@℃ /%@℃ \n%@", dayStr, lowStr, highStr, conditions]; //打印輸出 if (counter == 0)//第一個樹結點 { day_of_weekcLable1.text = tempStrToDisp; CALayer *layer = [iconImage1 layer]; [layer setMasksToBounds:YES]; [layer setCornerRadius:5.0]; [layer setBorderWidth:1.0]; [layer setBorderColor:[UIColor blackColor].CGColor]; iconImage1.image = [[UIImage alloc] initWithData:data]; } if (counter == 1)//第二個樹結點 { day_of_weekcLable2.text = tempStrToDisp; CALayer *layer = [iconImage2 layer]; [layer setMasksToBounds:YES]; [layer setCornerRadius:5.0]; [layer setBorderWidth:1.0]; [layer setBorderColor:[UIColor blackColor].CGColor]; iconImage2.image = [[UIImage alloc]initWithData:data]; } if (counter == 2)//第三個樹結點 { day_of_weekcLable3.text = tempStrToDisp; CALayer *layer = [iconImage3 layer]; [layer setMasksToBounds:YES]; [layer setCornerRadius:5.0]; [layer setBorderWidth:1.0]; [layer setBorderColor:[UIColor blackColor].CGColor]; iconImage3.image = [[UIImage alloc]initWithData:data]; } if (counter == 3)//第四個樹結點 { day_of_weekcLable4.text = tempStrToDisp; CALayer *layer = [iconImage4 layer]; [layer setMasksToBounds:YES]; [layer setCornerRadius:5.0]; [layer setBorderWidth:1.0]; [layer setBorderColor:[UIColor blackColor].CGColor]; iconImage4.image = [[UIImage alloc]initWithData:data]; } //計數加1,進行循環 counter = counter + 1; } }//循環結束 } //調用系統方法進行重寫 - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict { //NSLog(@"XML Parser 1 ... elementName ... %@", elementName); //依此得到葉子結點和其屬性值 if ([elementName isEqualToString:@"day_of_week"]) { NSString *tempStr = [attributeDict objectForKey:@"data"]; //NSLog(@"day-of-week: %@", tempStr); [arryDataMutable addObject:tempStr]; } if ([elementName isEqualToString:@"low"]) { NSString *tempStr = [attributeDict objectForKey:@"data"]; [arryDataMutable addObject:tempStr]; } if ([elementName isEqualToString:@"high"]) { NSString *tempStr = [attributeDict objectForKey:@"data"]; [arryDataMutable addObject:tempStr]; } if ([elementName isEqualToString:@"condition"]) { NSString *tempStr = [attributeDict objectForKey:@"data"]; [arryDataMutable addObject:tempStr]; } if ([elementName isEqualToString:@"icon"]) { NSString *tempStr = [attributeDict objectForKey:@"data"]; [arryDataMutable addObject:tempStr]; } } - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { //NSLog(@"XML Parser 2 ..."); //NSLog(@"string ... %@", string); } - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { //NSLog(@"XML Parser 3 ..."); //NSLog(@"elementName: %@", elementName); //NSLog(@"namespaceURI: %@", namespaceURI); //NSLog(@"qName: %@", qName); }
部分注釋不合理，請自行斟酌。

完美解析Google weather API,得到天氣信息并顯示詳細代碼