PropertyGrid 控件如何显示两层嵌套的动态 JSON 对象？

Question

我有一个需求，我的几个同事的配置文件要用PropertyGrid控件统一显示，我参考下面的帖子实现了：https://www.codeproject.com/Articles/193462/Using-PropertyGrid-to-Display-and-Edit-Dynamic-Obj。

我的方法是：先定义一个ConfigObject对象，然后使用JsonConvert.Convert(Newtonsoft.Json)将json配置文件反序列化成ConfigObject对象，然后赋值给PropertyGrid.SelectedObject。但是这样我只能显示和编辑一层嵌套的json对象，如果嵌套结构多于两层，那么嵌套的属性字段就无法编辑了。

考虑以下两级 JSON 结构：

{
  "DAMultiCast": "18:80:c2:00:00:0e",
  "SA": "18:60:24:A8:77:FF",
  "gPTPType": "0x88f7",
  "AVTPType": "0x22f0",
  "Initial": {
    "SyncMessageType": "0x10",
    "FollowupMessageType": "0x18",
    "ReqMessageType": "0x12",
    "RespMessageType": "0x13",
    "RespFollowupMessageType": "0x1A",
    "versionPTP": "0x02",
    "SyncMessagelength": "44",
    "FollowupMessagelength": "76",
    "ReqMessagelength": "54",
    "subdomainnumber": "0",
    "resv0": "0x00",
    "Syncflagfield": "0x0208",
    "Followupflagfield": "0x0008",
    "correctionField": "00:00:00:00:00:00:00:00",
    "resv1": "00:00:00:00",
    "SyncClockIdentity": "01:02:03:ff:fe:46:76:34",
    "RespClockIdentity": "00:22:97:ff:fe:80:0d:f2",
    "sourcePortId": "0x0001",
    "sequenceId": "143",
    "SyncControlField": "0",
    "FollowupControlField": "2",
    "DelayReqControlField": "5",
    "logMessagePeriod": "-3",
    "tlvType": "3",
    "lengthField": "28",
    "organizationId": "32962",
    "organizationSubType": "1",
    "cumulativeScaledRateOffset": "0",
    "gmTimeBaseIndicator": "0",
    "lastGmPhaseChange": "00:00:00:00:00:00:00:00:00:00:00:00",
    "scaledLastGmFreqChange": "0",
    "requestingPortIdentity": "01:02:03:ff:fe:46:76:34",
    "requestingPortId": "1"
  },
  "TM1_TG1_6.1.1B": {
    "WaitTime1": "10",
    "WaitTime2": "2"
  }
}

Answer 1

这可能会提示您实现目标。

来源1：Dynamically Create a Class at Runtime
来源2：PropertyGrid Browsable not found for entity framework created property, how to find it?
来源3：Make a Property Read-Only in PropertyGrid

输出：

代码：

private void loadJsonToPropertyGrid(string jsonString)
    {
        var jsonObject = JsonConvert.DeserializeObject<JObject>(jsonString);
        var obj = createClass("Item", jsonObject);
        var customClass = JsonConvert.DeserializeObject(jsonString, obj.GetType());
        var customClassType = customClass.GetType();

        DynamicTypeDescriptor typeDescriptor = new DynamicTypeDescriptor(customClassType);

        var propertyDescriptorList = typeDescriptor.Properties.Cast<PropertyDescriptor>().ToList()
        .Where(p => p.PropertyType.Name != "String").ToList();

        propExpandAndReadOnly(propertyDescriptorList);

        propertyGrid1.SelectedObject = typeDescriptor.FromComponent(customClass);
    }

    private void propExpandAndReadOnly(List<PropertyDescriptor> propertyDescriptorList)
    {
        foreach (var propertyDescriptor in propertyDescriptorList)
        {
            propertyDescriptor.SetReadOnlyAttribute(true);
            propertyDescriptor.SetExpandableAttribute(true);

            DynamicTypeDescriptor typeDescriptor = new DynamicTypeDescriptor(propertyDescriptor.PropertyType);
            var chilPropertyDescriptorList = typeDescriptor.Properties.Cast<PropertyDescriptor>().ToList()
            .Where(p => p.PropertyType.Name != "String").ToList();
            propExpandAndReadOnly(chilPropertyDescriptorList);
        }
    }

    private Type[] getPropertiesType(string[] properties, JObject jsonObject)
    {
        var propertyTypes = new List<Type>();

        foreach (var property in properties)
        {
            var jToken = jsonObject.GetValue(property);
            Type propertyType;

            if (jToken.HasValues)
            {
                var obj = createClass(property, (JObject)jsonObject.GetValue(property));
                propertyType = obj.GetType();
            }
            else
            {
                propertyType = typeof(string);
            }

            propertyTypes.Add(propertyType);
        }

        return propertyTypes.ToArray();
    }

    private object createClass(string name, JObject jsonObject)
    {
        MyClassBuilder MCB = new MyClassBuilder(name);
        var properties = jsonObject.Properties().Select(p => p.Name).ToArray();
        var propertiesType = getPropertiesType(properties, jsonObject);
        var obj = MCB.CreateObject(properties, propertiesType);

        return obj;
    }

更新
创建PropertyDescriptorExtensions

public static class PropertyDescriptorExtensions
{
    public static void SetReadOnlyAttribute(this PropertyDescriptor p, bool value)
    {
        var attributes = p.Attributes.Cast<Attribute>()
            .Where(x => !(x is ReadOnlyAttribute)).ToList();

        attributes.Add(new ReadOnlyAttribute(value));

        typeof(MemberDescriptor).GetProperty("AttributeArray",
            BindingFlags.Instance | BindingFlags.NonPublic)
            .SetValue((MemberDescriptor)p, attributes.ToArray());
    }

    public static void SetExpandableAttribute(this PropertyDescriptor p, bool value)
    {
        var attributes = p.Attributes.Cast<Attribute>()
            .Where(x => !(x is ReadOnlyAttribute)).ToList();

        if (value)
        {
            attributes.Add(new TypeConverterAttribute(typeof(ExpandableObjectConverter)));
        }

        typeof(MemberDescriptor).GetProperty("AttributeArray",
            BindingFlags.Instance | BindingFlags.NonPublic)
            .SetValue((MemberDescriptor)p, attributes.ToArray());
    }
}

编码愉快，干杯！