iOS开发之字典(NSDictionary)和JSON字符串(NSString)之间互转

1. 字典转Json字符串

+ (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 stringByReplacingOccurrencesOfString:@"\n" withString:@""];

return jsonString;
}

2. JSON字符串转化为字典

+ (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;
}