SelectToken provides a method to query LINQ to JSON using a single string path to a desired JToken. SelectToken makes dynamic queries easy because the entire query is defined in a string.
string name = (string)o.SelectToken("Manufacturers[0].Name");
SelectToken
SelectToken is a method on JToken and takes a string path to a child token. SelectToken returns the child token or a null reference if a token couldn't be found at the path's location.
The
path is made up of property names and array indexes separated by periods. Array indexes
can use either square or round brackets. Both
of the following are valid paths and are equivalent to each other: Manufacturers[0].Name
and Manufacturers(0).Name.
JObject o = JObject.Parse(@"{
""Stores"": [
""Lambton Quay"",
""Willis Street""
],
""Manufacturers"": [
{
""Name"": ""Acme Co"",
""Products"": [
{
""Name"": ""Anvil"",
""Price"": 50
}
]
},
{
""Name"": ""Contoso"",
""Products"": [
{
""Name"": ""Elbow Grease"",
""Price"": 99.95
},
{
""Name"": ""Headlight Fluid"",
""Price"": 4
}
]
}
]
}");
string name = (string)o.SelectToken("Manufacturers[0].Name");
// Acme Co
decimal productPrice = (decimal)o.SelectToken("Manufacturers[0].Products[0].Price");
// 50
string productName = (string)o.SelectToken("Manufacturers[1].Products[0].Name");
// Elbow Grease
SelectToken with LINQ
SelectToken can be used in combination with standard LINQ methods.
IList<string> storeNames = o.SelectToken("Stores").Select(s => (string)s).ToList();
// Lambton Quay
// Willis Street
IList<string> firstProductNames = o["Manufacturers"].Select(m => (string)m.SelectToken("Products[1].Name")).ToList();
// null
// Headlight Fluid
decimal totalPrice = o["Manufacturers"].Sum(m => (decimal)m.SelectToken("Products[0].Price"));
// 149.95