解析JSON在Objective-C

http://maps.googleapis.com/maps/api/geocode/json?address=canada&sensor=false

在Objective-C

。我試圖讓在「邊界」東北緯度，這是我寫嘗試做到這一點（feed是NSDictionary對象）的代碼：

NSArray *results = [feed objectForKey:@"results"]; 
NSDictionary *firstResult = [results objectAtIndex:0]; 
NSArray *geometry = [firstResult objectForKey:@"geometry"]; 
NSDictionary *firstGeo = [geometry objectAtIndex:0]; 
NSArray *bounds = [firstGeo objectForKey:@"bounds"]; 
NSDictionary *northeast = [bounds objectAtIndex:0]; 
NSString *neLat = [[NSString alloc] initWithString:[northeast objectForKey:@"lat"]];

即使它編譯罰款和JSON數據是有效的，當我運行它，我得到這個錯誤：

[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance 0xa672390 2012-02-24 01:32:06.321 Geo[570:11603] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance 0xa672390'

我不知道爲什麼會這樣，我順利拿到long_name前...任何幫助是極大的讚賞:)

謝謝提前！

來源

2012-02-24 The Awesome Guy

該geometry和bounds已經是詞典。

 "geometry" : { // <-- a dictionary! 
     "bounds" : { // <-- also a dictionary! 
      "northeast" : { 
       "lat" : 83.1150610, 
       "lng" : -52.62040200000001 
      },

所以，你應該寫

NSDictionary *geometry = [firstResult objectForKey:@"geometry"]; 
NSDictionary *bounds = [geometry objectForKey:@"bounds"]; 
NSDictionary *northeast = [bounds objectForKey:@"northeast"];

來源

2012-02-24 06:47:51 kennytm

請不要忘記'-valueForKeyPath：'：'[firstResult valueForKeyPath：@「geometry.bounds.northeast」]' – nielsbot 2012-02-24 06:54:57

@nielsbot：注意'-valueForKeyPath：'效率極低。 – kennytm 2012-02-24 11:23:11

好吧，執行效率可能不高，但有效輸入！ – nielsbot 2012-02-24 19:03:07

檢查下面的語句。

NSArray *geometry = [firstResult objectForKey:@"geometry"];

它似乎是geometry，它不返回NSArray。它返回NSDictionary

來源

2012-02-24 06:50:49 Ilanchezhian

解析JSON在Objective-C

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