How to recursively populate a TreeView with JSON data

Talha Talip Açıkgöz picture Talha Talip Açıkgöz · Sep 24, 2016 · Viewed 16.2k times · Source

I have a winforms treeview, I can read data automatically, (a node that is equal to key, and a node inside that is equal to value), but when reading object type, the values inside it are not going to be child of object node (key of object), (maybe I couldnt explain well, here is a screenshot and my methods.)

layer0 needs to be inside textures and scale needs to be inside display

layer0 needs to be inside textures and scale needs to be inside display

My Json:

{
"parent": "builtin/generated",
"textures": {
    "layer0": "mm:items/iron_dust"
},
"display": {       
        "scale": [ 1.7, 1.7, 1.7 ]
 }
}

My method to auto detect(not all mine actually)

private void Form1_Load(object sender, EventArgs e)
    {
        StreamReader reader = new StreamReader(path);
        string json = reader.ReadToEnd();
        reader.Close();
        JObject obj = JObject.Parse(json);
        getAllProperties(obj);
    }

    void getAllProperties(JToken children)
    {
        TreeNode mainNode = treeView1.Nodes[0];
        mainNode.Text = Path.GetFileNameWithoutExtension(path);
        foreach (JToken child in children.Children())
        {
            var property = child as JProperty;
            if (property != null)
            {
                if (property.Value.Type == JTokenType.String)
                {
                    TreeNode keyNode = mainNode.Nodes.Add(property.Name);
                    keyNode.Nodes.Add(property.Value.ToString());
                }
                if (property.Value.Type == JTokenType.Array)
                {
                    JArray array = (JArray)property.Value;
                    TreeNode node = mainNode.Nodes.Add(property.Name);
                    for (int i = 0; i < array.Count; i++)
                    {
                        node.Nodes.Add(array[i].ToString());
                    }
                }
                if (property.Value.Type == JTokenType.Object)
                {
                    TreeNode topNode = mainNode.Nodes.Add(property.Name.ToString());
                    foreach (var item in property)
                    {
                        if (item.Type == JTokenType.String)
                        {
                             if (property.Value.Type == JTokenType.String)
                {
                    TreeNode keyNode = topNode.Nodes.Add(property.Name);
                    keyNode.Nodes.Add(property.Value.ToString());
                }
                if (property.Value.Type == JTokenType.Array)
                {
                    JArray array = (JArray)property.Value;
                    TreeNode node = topNode.Nodes.Add(property.Name);
                    for (int i = 0; i < array.Count; i++)
                    {
                        node.Nodes.Add(array[i].ToString());
                    }
                }
                        }
                    }
                }


                    // Console.WriteLine(property.Name + ":" + property.Value);//print all of the values
                }
                getAllProperties(child);
            }
        }

    }

I tried to get parent, but it didnt have name and value properties :S. Any help? (Sorry for language mistakes)

Answer

dbc picture dbc · Sep 24, 2016

The problem is that, as you recursively descend the JToken hierarchy, you also need to recursively descend the TreeNode hierarchy you are creating, adding child nodes to the parent node just created, rather than the root node, along the lines of Recursion, parsing xml file with attributes into treeview c#.

Thus if you do:

    private void Form1_Load(object sender, EventArgs e)
    {
        using (var reader = new StreamReader(path))
        using (var jsonReader = new JsonTextReader(reader))
        {
            var root = JToken.Load(jsonReader);
            DisplayTreeView(root, Path.GetFileNameWithoutExtension(path));
        }
    }

    private void DisplayTreeView(JToken root, string rootName)
    {
        treeView1.BeginUpdate();
        try
        {
            treeView1.Nodes.Clear();
            var tNode = treeView1.Nodes[treeView1.Nodes.Add(new TreeNode(rootName))];
            tNode.Tag = root;

            AddNode(root, tNode);

            treeView1.ExpandAll();
        }
        finally
        {
            treeView1.EndUpdate();
        }
    }

    private void AddNode(JToken token, TreeNode inTreeNode)
    {
        if (token == null)
            return;
        if (token is JValue)
        {
            var childNode = inTreeNode.Nodes[inTreeNode.Nodes.Add(new TreeNode(token.ToString()))];
            childNode.Tag = token;
        }
        else if (token is JObject)
        {
            var obj = (JObject)token;
            foreach (var property in obj.Properties())
            {
                var childNode = inTreeNode.Nodes[inTreeNode.Nodes.Add(new TreeNode(property.Name))];
                childNode.Tag = property;
                AddNode(property.Value, childNode);
            }
        }
        else if (token is JArray)
        {
            var array = (JArray)token;
            for (int i = 0; i < array.Count; i++)
            {
                var childNode = inTreeNode.Nodes[inTreeNode.Nodes.Add(new TreeNode(i.ToString()))];
                childNode.Tag = array[i];
                AddNode(array[i], childNode);
            }
        }
        else
        {
            Debug.WriteLine(string.Format("{0} not implemented", token.Type)); // JConstructor, JRaw
        }
    }

You will get the following tree view structure:

enter image description here