How to Efficiently Find Specific JTokens by Name within a Nested JObject Hierarchy?

Searching for a Specific JToken by Name in a JObject Hierarchy

Background:

When dealing with complex JSON structures, it's often necessary to retrieve specific values based on their token names. This can be challenging without a built-in method.

Built-in Method:

Unfortunately, the NewtonsoftJson library does not provide a direct method to retrieve a JToken by name.

Recursive Method:

To overcome this limitation, a recursive method can be implemented to search for JTokens by name within a JObject hierarchy. Here's an example:

public static class JsonExtensions
{
    public static List<JToken> FindTokens(this JToken containerToken, string name)
    {
        List<JToken> matches = new List<JToken>();
        FindTokens(containerToken, name, matches);
        return matches;
    }

    private static void FindTokens(JToken containerToken, string name, List<JToken> matches)
    {
        if (containerToken.Type == JTokenType.Object)
        {
            foreach (JProperty child in containerToken.Children<JProperty>())
            {
                if (child.Name == name)
                {
                    matches.Add(child.Value);
                }
                FindTokens(child.Value, name, matches);
            }
        }
        else if (containerToken.Type == JTokenType.Array)
        {
            foreach (JToken child in containerToken.Children())
            {
                FindTokens(child, name, matches);
            }
        }
    }
}

Demo:

Here's an example demonstrating the usage of this extension method:

string json = @"
{
    ""routes"": [
        {
            ""bounds"": {
                ""northeast"": {
                    ""lat"": 50.4639653,
                    ""lng"": 30.6325177
                },
                ""southwest"": {
                    ""lat"": 50.4599625,
                    ""lng"": 30.6272425
                }
            },
            ""legs"": [
                {
                    ""distance"": {
                        ""text"": ""1.7 km"",
                        ""value"": 1729
                    },
                    ""duration"": {
                        ""text"": ""4 mins"",
                        ""value"": 223
                    }
                },
                {
                    ""distance"": {
                        ""text"": ""2.3 km"",
                        ""value"": 2301
                    },
                    ""duration"": {
                        ""text"": ""5 mins"",
                        ""value"": 305
                    }
                }
            ]
        }
    ]
}";

JObject jo = JObject.Parse(json);

foreach (JToken token in jo.FindTokens("text"))
{
    Console.WriteLine(token.Path + ": " + token.ToString());
}

Output:

routes[0].legs[0].distance.text: 1.7 km
routes[0].legs[0].duration.text: 4 mins
routes[0].legs[1].distance.text: 2.3 km
routes[0].legs[1].duration.text: 5 mins

The above is the detailed content of How to Efficiently Find Specific JTokens by Name within a Nested JObject Hierarchy?. For more information, please follow other related articles on the PHP Chinese website!