c# reflection read from json and fieldinfo.setvalue error

i got a question here,hope warmheat developer help.

this is the problem i meet:

i want to save a class instance's fields due to reflection,the code below:

private void SaveFields()
{
    fieldItemList.Clear();
    FieldInfo[] fields = GetType().GetFields(BindingFlags.Public | BindingFlags.Instance);
    for (int i = 0; i < fields.Length; i++)
    {
        FieldInfo finfo = fields[i];
        FieldItem item = new FieldItem()
        {
            ValName = finfo.Name,
            ValType = finfo.FieldType,
            ValValue = finfo.GetValue(this),
        };
        fieldItemList.Add(item);
    }
    string json = JsonModule.GetInstance().Serialize(fieldItemList);
    json = JsonModule.GetInstance().FormatJsonString(json);
    Debug.LogFormat("json = {0}", json);
    File.WriteAllText(@"E:\GithubRepo\ShaderSamples\ShaderSamples\fields.json", json);
}

it works,and the saved json like this:

[
{
    "ValName": "fVar",
    "ValType": "System.Single, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089",
    "ValValue": 2.0
},
{
    "ValName": "iVar",
    "ValType": "System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089",
    "ValValue": 1
},
{
    "ValName": "Gears",
    "ValType": "GearParam[], Assembly-CSharp, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null",
    "ValValue": [
        {
            "Vec3": {
                "x": 1.0,
                "y": 2.0,
                "z": 3.0
            },
            "Vec2": {
                "x": 1.0,
                "y": 2.0
            },
            "FVar": 1.0,
            "IVar": 2
        }
    ]
}

]

then when i use it for fill in new class instance's fields,code like this:

private void ApplyFields()
{
    string json = File.ReadAllText(@"E:\GithubRepo\ShaderSamples\ShaderSamples\fields.json");
    fieldItemList = JsonModule.GetInstance().Deserialize<List<FieldItem>>(json);
    Debug.LogFormat("fieldItemList = {0}", fieldItemList.Count);
    FieldInfo[] fields = GetType().GetFields(BindingFlags.Public | BindingFlags.Instance);
    for (int i = 0; i < fields.Length; i++)
    {
        FieldInfo finfo = fields[i];
        for (int k = 0; k < fieldItemList.Count; k++)
        {
            FieldItem item = fieldItemList[k];
            if (finfo.Name == item.ValName)
            {
                finfo.SetValue(this, item.ValValue);
            }
        }
    }
}

it cause error:

ArgumentException: Object of type 'System.Double' cannot be converted to type 'System.Single'. System.RuntimeType.CheckValue (System.Object value, System.Reflection.Binder binder, System.Globalization.CultureInfo culture, System.Reflection.BindingFlags invokeAttr) (at :0) System.Reflection.MonoField.SetValue (System.Object obj, System.Object val, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Globalization.CultureInfo culture) (at :0) System.Reflection.FieldInfo.SetValue (System.Object obj, System.Object value) (at :0) TestReflectEnum.ApplyFields () (at Assets/Scripts/TestReflectEnum.cs:82)

i think reflect fieldinfo.setvalue need the exactly object type to fill in,so i change code like this:

object obj = Convert.ChangeType(item.ValValue, item.ValType);
finfo.SetValue(this, obj);

but still cause error:

InvalidCastException: Object must implement IConvertible. System.Convert.ChangeType (System.Object value, System.Type conversionType, System.IFormatProvider provider) (at :0) System.Convert.ChangeType (System.Object value, System.Type conversionType) (at :0) TestReflectEnum.ApplyFields () (at Assets/Scripts/TestReflectEnum.cs:82)

now the only way for me is write out all kind of object type condition,and change type object one by one,it's so troublesome way,i hope there is a common function for read object from txt/json,and could setvalue right - -