Unity读取和解析JSON文件(3)-JsonReader和JsonWriter

旧城等待， 2023-07-12 06:24 7阅读 0赞

*  Unity版本：2018.4.17

JsonMapper的底层是JsonReader和JsonWriter，这两个类也是LitJson库的基础，它们提供了流式方式读写JSON数据的接口。

## 使用JsonReader ##

通过`JsonReader`可以得到JSON数据的所有信息，包括字段名、字段类型，字段值等。

using LitJson;
    using System;
    
    public class DataReader
    {
        public static void Main()
        {
            string sample = @"{
                ""name""  : ""Bill"",
                ""age""   : 32,
                ""awake"" : true,
                ""n""     : 1994.0226,
                ""note""  : [ ""life"", ""is"", ""but"", ""a"", ""dream"" ]
              }";
    
            PrintJson(sample);
        }
    
        public static void PrintJson(string json)
        {
            JsonReader reader = new JsonReader(json);
    
            Console.WriteLine ("{0,14} {1,10} {2,16}", "Token", "Value", "Type");
            Console.WriteLine (new String ('-', 42));
    
            // The Read() method returns false when there's nothing else to read
            while (reader.Read()) {
                string type = reader.Value != null ?
                    reader.Value.GetType().ToString() : "";
    
                Console.WriteLine("{0,14} {1,10} {2,16}",
                                  reader.Token, reader.Value, type);
            }
        }
    }

#### 输出如下 ####

Token         Value             Type
    ------------------------------------------
    ObjectStart                            
    PropertyName  name              System.String
    String        Bill              System.String
    PropertyName  age               System.String
      Int         32                System.Int32
    PropertyName  awake             System.String
    Boolean       True              System.Boolean
    PropertyName  n                 System.String
    Double        1994.0226         System.Double
    PropertyName  note              System.String
    ArrayStart                            
    String        life              System.String
    String        is                System.String
    String        but               System.String
    String        a                 System.String
    String        dream             System.String
    ArrayEnd                            
    ObjectEnd

## 使用JsonWriter ##

`JsonWriter`类非常简单，请记住，如果要将某个任意对象转换为JSON字符串，通常只需使用`JsonMapper.ToJson`。

using LitJson;
    using System;
    using System.Text;
    
    public class DataWriter
    {
        public static void Main()
        {
            StringBuilder sb = new StringBuilder();
            JsonWriter writer = new JsonWriter(sb);
    
            writer.WriteArrayStart();
            writer.Write(1);
            writer.Write(2);
            writer.Write(3);
    
            writer.WriteObjectStart();
            writer.WritePropertyName("color");
            writer.Write("blue");
            writer.WriteObjectEnd();
    
            writer.WriteArrayEnd();
    
            Console.WriteLine(sb.ToString());
        }
    }

#### 输出如下 ####

[1,2,3,{"color":"blue"}]