stringByRemovingPercentEncoding 对空字符对象的转化在ios8以下为nil，ios以上为@“”

        

   ios 7.x 出现了一个闪退，调试代码发现stringByRemovingPercentEncoding 对空字符对象的转化在ios8以下为nil，ios8以上为@“”。value 为nil导致闪退。

代码如下。

- (NSDictionary *)getParams:(NSString *)query {

    NSMutableDictionary *queryStringDictionary =@{}.mutableCopy;

    NSArray *urlComponents = [querycomponentsSeparatedByString:@"&"];

    for (NSString *keyValuePairin urlComponents)

    {

        NSArray *pairComponents = [keyValuePaircomponentsSeparatedByString:@"="];

        NSString *key = [[pairComponentsfirstObject] stringByRemovingPercentEncoding];

        NSString *value = [[pairComponentslastObject] stringByRemovingPercentEncoding];

        if(value !=nil && key != nil)//防止ios 7.x闪退  linqx 2016 11 01

        {

            [queryStringDictionary setObject:valueforKey:key];

        }

    }

    return queryStringDictionary.copy;

}