iOS開發解決json串中的NSNull類型

標籤：

後端返回的資料中總會出現一些NSNull類型，當我們一處理常式就會崩潰，因此想到把返回的資料中的NSNull類型全部轉換成@""Null 字元串。下面是轉化方法：

1 自訂的幾個方法：放在NSDictionary類別中

#pragma mark - 私人方法

//將NSDictionary中的Null類型的項目轉化成@""

+(NSDictionary *)nullDic:(NSDictionary *)myDic

{

    NSArray *keyArr = [myDic allKeys];

    NSMutableDictionary *resDic = [[NSMutableDictionary alloc]init];

    for (int i = 0; i < keyArr.count; i ++)

    {

        id obj = [myDic objectForKey:keyArr[i]];

        

        obj = [self changeType:obj];

        

        [resDic setObject:obj forKey:keyArr[i]];

    }

    return resDic;

}

 

//將NSDictionary中的Null類型的項目轉化成@""

+(NSArray *)nullArr:(NSArray *)myArr

{

    NSMutableArray *resArr = [[NSMutableArray alloc] init];

    for (int i = 0; i < myArr.count; i ++)

    {

        id obj = myArr[i];

        

        obj = [self changeType:obj];

        

        [resArr addObject:obj];

    }

    return resArr;

}

 

//將NSString類型的原路返回

+(NSString *)stringToString:(NSString *)string

{

    return string;

}

 

//將Null類型的項目轉化成@""

+(NSString *)nullToString

{

    return @"";

}

 

#pragma mark - 公有方法

//類型識別:將所有的NSNull類型轉化成@""

+(id)changeType:(id)myObj

{

    if ([myObj isKindOfClass:[NSDictionary class]])

    {

        return [self nullDic:myObj];

    }

    else if([myObj isKindOfClass:[NSArray class]])

    {

        return [self nullArr:myObj];

    }

    else if([myObj isKindOfClass:[NSString class]])

    {

        return [self stringToString:myObj];

    }

    else if([myObj isKindOfClass:[NSNull class]])

    {

        return [self nullToString];

    }

    else

    {

        return myObj;

    }

}

 

2 使用方法（綠色的是實際用到的代碼）

 

（1）原始的json串：後端返回的json串裡麵包含類型NSString，NSArray，NSDictionary，NSNull類型。

 

{"status":1,"service_name":null,"service_id":null,"img_url":"http:\/\/api.jgfw.me\/assets\/uploads\/files\/","price":null,"num":3,"service_info":{"service_type":null,"service_time":null,"service_detail":null,"customer_name":null,"customer_phone":null,"customer_address":"","new_jishi":"","old_jishi":null,"lat":null,"lon":null},"order_info":{"order_no":"E15031267469289848688","pay_time":null,"order_time":null,"price":0,"order_state":null}}

 

（2）用SBJson庫:json串轉換成字典

NSDictionary *jsonDic = [retString JSONValue];

 （3）用自訂方法轉換後的結果：將字典中所有的NSNull類型轉換成@""

 NSDictionary *dict = [NSDictionary changeType:jsonDic];

{

    "img_url" = "http://api.jgfw.me/assets/uploads/files/";

    num = 3;

    "order_info" =     {

        "order_no" = E15031267469289848688;

        "order_state" = "";

        "order_time" = "";

        "pay_time" = "";

        price = 0;

    };

    price = "";

    "service_id" = "";

    "service_info" =     {

        "customer_address" = "";

        "customer_name" = "";

        "customer_phone" = "";

        lat = "";

        lon = "";

        "new_jishi" = "";

        "old_jishi" = "";

        "service_detail" = "";

        "service_time" = "";

        "service_type" = "";

    };

    "service_name" = "";

    status = 1;

 

}

iOS開發解決json串中的NSNull類型