在方法之間傳遞NSString

Question

我已經有了一些新手問題。

我得到了這個方法來根據GPS座標確定iPhone所在的郵政編碼。反向地理編碼。我的方法很有效，我知道這一點，因爲將正確的郵政編碼寫入標籤沒有問題。

但我需要這個郵政編碼被存儲在一個字符串，我可以使用一個方法，我用來組成一個短信。

任何人都可以幫助我嗎？

告訴我，如果源代碼是必要的！ （只是目前沒有坐在我的工作comp）

很明顯，我一直誤解，應該發佈som代碼。

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{ 
    NSLog(@"didUpdateToLocation: %@", newLocation); 
    CLLocation *currentLocation = newLocation; 


    // Reverse Geocoding 
    NSLog(@"Resolving the Address"); 
    [geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error) { 
     NSLog(@"Found placemarks: %@, error: %@", placemarks, error); 
     if (error == nil && [placemarks count] > 0) { 
      placemark = [placemarks lastObject]; 
      **postalCode** = [NSString stringWithFormat:@"%@", 
          placemark.postalCode]; 
     } else { 
      NSLog(@"%@", error.debugDescription); 
     } 
    } ]; 

} 

在這裏，我嘗試保存的NSString命名POSTALCODE裏面的郵政編碼（帶強調「**」）

我嘗試在短信作曲家再次裝入

-(void)displaySMSComposerSheet 
{ 
    CLLocation *currentLocation; 


    // Reverse Geocoding 
    NSLog(@"Resolving the Address"); 
    [geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error) { 
     NSLog(@"Found placemarks: %@, error: %@", placemarks, error); 
     if (error == nil && [placemarks count] > 0) { 
      placemark = [placemarks lastObject]; 
      postalCode = [NSString stringWithFormat:@"%@", 
          placemark.postalCode]; 
     } else { 
      NSLog(@"%@", error.debugDescription); 
     } 
    } ]; 

    MFMessageComposeViewController *picker = [[MFMessageComposeViewController alloc] init]; 
    picker.recipients = [NSArray arrayWithObjects:@"1220", nil]; 
    picker.body = [NSString stringWithFormat:@"Dog %@", (placemark.)postalCode]; 
    picker.messageComposeDelegate = self; 

    [self presentModalViewController:picker animated:YES]; 

} 

只打印在短信窗口中輸出： Dog（null） 而且我確定我有座標，它們會在輸出中打印出來。

希望這有助於理解這個問題更好

Answer 1

如果您要訪問整個viewControllers postalCode，你可以只將其保存到NSUserDefaults

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{ 
    // ... 
    NSString *postalCode = [NSString stringWithFormat:@"%@", 
          placemark.postalCode]; 
    [[NSUserDefaults standardDefaults] setObject:postalCode forKey:@"postalCode"]; 
    // ... 
} 

，並再次將其裝入

-(void)displaySMSComposerSheet 
{ 
    // ... 
    NSString *postalCode = [[NSUserDefaults standardDefaults] objectForKey:@"postalCode"]; 
    // .... 
} 

編輯：你確定placemark和postalCode是已經設定（即 - locationManager:didUpdateToLocation:fromLocation:已被調用）？如果在確定位置之前調用displaySMSComposerSheet，則此行爲是正常的。

編輯2：從您的代碼，它看起來像你忘了告訴locationManager開始更新位置。以下內容添加到viewDidLoad：

locationManager.delegate = self; 
[locationManager startUpdatingLocation]; 

Answer 2

嘗試

picker.body = [NSString stringWithFormat:@"Dog %@", postalCode]; 

Answer 3

-(void)displaySMSComposerSheet 
{ 
    CLLocation *currentLocation; 


    // Reverse Geocoding 
    NSLog(@"Resolving the Address"); 
    [geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error) { 
     NSLog(@"Found placemarks: %@, error: %@", placemarks, error); 
     if (error == nil && [placemarks count] > 0) { 
      placemark = [placemarks lastObject]; 
      postalCode = [NSString stringWithFormat:@"%@", 
          placemark.postalCode]; 
      [self showMailComposer:postalcode]; // method call 
     } else { 
      NSLog(@"%@", error.debugDescription); 
     } 
    } ]; 



} 

-(void)showMailComposer:(NSString *)postalCode{ 
    MFMessageComposeViewController *picker = [[MFMessageComposeViewController alloc] init]; 
    picker.recipients = [NSArray arrayWithObjects:@"1220", nil]; 
    picker.body = [NSString stringWithFormat:@"Dog %@", postalCode]; 
    picker.messageComposeDelegate = self; 

    [self presentModalViewController:picker animated:YES]; 
}