iOS NSDictionary转json / 字典转json - iOS

1、示例一：

JMSGUser *fromUser = [message fromUser];

NSDictionary *fromUserDict = @{@"username": [NSString stringWithFormat:@"%@", fromUser.username],

@"nickname":[NSString stringWithFormat:@"%@",fromUser.nickname],

@"signature":[NSString stringWithFormat:@"%@",fromUser.signature],

@"avatar":[NSString stringWithFormat:@"%@",fromUser.avatar]};

NSData *jsonData=[NSJSONSerialization dataWithJSONObject:fromUserDict options:NSJSONWritingPrettyPrinted error:nil];

NSString *jsonString = [[NSString alloc]initWithData:jsonData encoding:NSUTF8StringEncoding];

NSMutableString *fromUserStr = [NSMutableString stringWithString:jsonString];

NSRange range = {0,jsonString.length};

//去掉字符串中的空格

[fromUserStr replaceOccurrencesOfString:@" " withString:@"" options:NSLiteralSearch range:range];

NSRange range2 = {0,fromUserStr.length};

//去掉字符串中的换行符

[fromUserStr replaceOccurrencesOfString:@"\n" withString:@"" options:NSLiteralSearch range:range2];

NSLog(@"jsonStr==%@",fromUserStr);

2、示例二：

C/C++ Code复制内容到剪贴板

NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
[dictionary setValue:@"hello" forKey:@"one"];
[dictionary setValue:@"world" forKey:@"two"];
[dictionary setValue:arry forKey:@"three"];
NSData *data=[NSJSONSerialization dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:nil];
NSString *jsonStr=[[NSString alloc]initWithData:datae coding:NSUTF8StringEncoding];
NSLog(@"jsonStr==%@",jsonStr);

输出结果为：

str=={

"one" : "hello",

"two" : "world",

"three" : [

"001",

"002",

"003"

]

}