c# - 在 C# 的静态类中使用 JsonConvert.DeserializeObject 进行动态转换

Question

我有一个公共(public)静态类设置，我在其中存储了一些公共(public)静态字段:

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Dynamic;
using System.IO;
using System.Reflection;

namespace testApp {
    public static class Settings {
        public static int appWidth = 800;
        public static int appHeight = 600;
        public static int layotCols = 1;
        public static int layotRows = 1;
        public static string TestString = "test";
        public static double TestFloat = 1.4;
        public static string[] TestStringArray = new[] { "1", "ee", "rrr"};
        public static List<string> TestStringArray1 = new List<string>() { "1", "2"};
        public static Dictionary<string,string> TestStringArray2 = new Dictionary<string, string> { { "key1", "value1" }, { "key2", "value2" } };
   }
}

现在我想将所有字段保存到文件中，但能够添加新字段而无需“手动”保存和读取它们。

我决定使用我的动态和反射技能，将所有字段列出到 ExpandoObject，然后是 JObject，然后是 File.WriteAllText 到“settings.ini”...令人难以置信，但它适用于所有字段类型，Newtonsoft.Json 可以序列化:

public static void saveSettings() {
    Type type = typeof(Settings); // Settings is static class with static properties

    dynamic dObject = new ExpandoObject();
    var exObject = dObject as IDictionary<String, object>;

    foreach(var setting in type.GetFields(System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.Public)) {
        exObject[setting.Name] = Convert.ChangeType(setting.GetValue(null), setting.FieldType); 
    }

    JObject obj = new JObject();
    obj = JObject.FromObject(dObject);

    File.WriteAllText("settings.ini", obj.ToString());
}

但是现在我在阅读这个文本文件时遇到了一些麻烦。我使用了标准的反射方法，只能读取几种数据类型，但可以读取数组和其他数据类型:

public static void loadSettings() {
    var settingsFile = File.ReadAllText("settings.ini");
    JObject obj = JObject.Parse(settingsFile);

    Type type = typeof(Settings);
    foreach(var setting in type.GetFields(System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.Public)) {
        if(obj[setting.Name]?.ToString() != null) {
            setting.SetValue(setting, Convert.ChangeType(obj[setting.Name],setting.FieldType));
        }
    }
}

我发现，Newtonsoft.Json 还可以使用 JsonConvert.DeserializeObject(object) 将对象反序列化并转换为多种类型。我试过:

setting.SetValue(setting, JsonConvert.DeserializeObject<setting.FieldType>(obj[setting.Name].ToString()));

但是它给出了编译错误...你能帮帮我吗？

Answer 1

您想使用重载 JsonConvert.DeserializeObject(String, Type) :

setting.SetValue(setting, JsonConvert.DeserializeObject(obj[setting.Name].ToString(), setting.FieldType));

或者，您可以使用 JToken.ToObject(Type)并避免不必要的字符串转换:

setting.SetValue(setting, obj[setting.Name].ToObject(setting.FieldType));

并且，自从第一个 Object 参数到 FieldInfo.SetValue(Object, Object)对于静态方法会被忽略，为了清楚起见，您可能只想传递 null:

setting.SetValue(null, obj[setting.Name].ToObject(setting.FieldType));

样本 fiddle .