1 /**
 2  试着得到一个json格式的json字符串
 3 
 4  @return json格式的json字符串
 5  */
 6 - (NSString *)WriteJsonTest{
 7     NSArray *currentDeviceArr = @[@"ipad mini",@"ipadAir2",@"ipad9.7",@"iPadPro10.5",@"iPad12.9"];
 8     NSArray *fontSizeArr = @[@18,@20,@22,@24,@26];
 9     NSArray *colorArr = @[@"red",@"blue",@"yellow",@"black",@"white"];
10     NSMutableArray <NSMutableDictionary *>*arrM = [NSMutableArray array];
11     for (NSInteger i = 0; i <fontSizeArr.count; i++) {
12         NSMutableDictionary *dictM = [NSMutableDictionary dictionary];
13         [dictM setObject:currentDeviceArr[i] forKey:@"currentDeviceType"];
14         [dictM setObject:colorArr[i] forKey:@"color"];
15         [dictM setObject:fontSizeArr[i] forKey:@"fontSize"];
16         [arrM addObject:dictM];
17     }
18     NSData *data = [NSJSONSerialization dataWithJSONObject:arrM options:NSJSONWritingPrettyPrinted error:nil];
19     NSString * jsonStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
20     //下边以字符串的形式打印出来内容可以直接放到查看json文件的地方，转换为json。直接转换出的json有时把中括号又变成小括号还有可能逗号的数目也有问题等。
21     WWLog(@"%@",jsonStr);
22     id json = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:nil];
23     if ([NSJSONSerialization isValidJSONObject:json]) {
24         WWLog(@"有效json");
25     }else{
26         WWLog(@"无效json");
27     }
28     WWLog(@"%@",json);
29     return jsonStr;
30 }