iOS-97-NSDictionary、NSString互转

/**
*  NSString-->NSDictionary
*/
- (NSDictionary *)dictionaryWithJsonString:(NSString *)jsonString {
if (jsonString == nil) {
return nil;
}

NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSError *err;
NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData
options:NSJSONReadingMutableContainers
error:&err];
if(err) {
NSLog(@"json解析失败：%@",err);
return nil;
}
return dic;
}

/**
*  NSDictionary-->NSString
*/
- (NSString*)convertToJSONData:(id)infoDict
{
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:infoDict
options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
error:&error];
NSString *jsonString = @"";
if (!jsonData){
NSLog(@"Got an error: %@", error);
}else{
jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
}

jsonString = [jsonString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];  //去除掉首尾的空白字符和换行字符
jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\n" withString:@""];
jsonString = [jsonString stringByReplacingOccurrencesOfString:@" " withString:@""];// 去掉空格
//    jsonString = [jsonString stringByReplacingOccurrencesOfString:@"\\" withString:@""];// 去掉斜杠
return jsonString;
}