关于字典、数组和json字符串的转化,主要用到的是NSJSONSerialization这个类里面的两个方法:
+ (nullable id)JSONObjectWithData:(NSData *)data options:(NSJSONReadingOptions)opt error:(NSError **)error;
+ (nullable NSData *)dataWithJSONObject:(id)obj options:(NSJSONWritingOptions)opt error:(NSError **)error;
看上面两个方法,不难发现,不管字典转化为json字符串,还是json字符串转化为字典,都需要先以NSData类型为中转。
//将jsonString转化为字典
- (NSDictionary *)transformStringIntoDictionary:(NSString *)jsonString {
//先将jsonString转化为NSData类型数据
NSData *data = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
NSError *error;
//将NSData类型转化为NSDictionary类型,也可以转化为NSArray类型
NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];
return dic;
}
//将字典/数组转化为jsonString
- (NSString *)transformDictionaryIntoString:(NSDictionary *)dictionary {
NSError *error;
//先将NSDictonary转化为NSData类型
NSData *data = [NSJSONSerialization dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:&error];
//再把NSdata类型转化为String类型
NSString *jsonString = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
return jsonString;
}