c# Parse JSON with no reference class? [duplicate] - c#

This question already has answers here:
How can I deserialize JSON to a simple Dictionary<string,string> in ASP.NET?
(22 answers)
Closed 3 years ago.
I have a JSON similar to the following:
{
"type": "FeatureCollection",
"totalFeatures": "unknown",
"features": [
{
"type": "Feature",
"id": "xxx",
"geometry": {
"type": "MultiPolygon",
"coordinates": [
[
570389.865,
4722149.567
],
[
570389.865,
4722149.567
]
]
}
}
]
}
Is there a way to get the coordinates property of the first feature without using substring or parsing it to an class that represents that JSON?
I'm looking for something standard for handling JSON strings as an Object, with methods for getting childs by name or similar.
Any help would be appreciated

You can use Newtonsoft.Json library.
Here's example of getting coordinates field (using JSONPath):
var parsed = JObject.Parse(yourJson);
// returns JToken (but actually it's JArray, derived from JToken)
var coordArrayToken = parsed.SelectToken("$.features[0].geometry.coordinates");
var coordinates = coordArrayToken.ToObject<decimal[][]>();
Of course you can use simple indexers:
var parsed = JObject.Parse(yourJson);
// returns JToken (but actually it's JArray, derived from JToken)
var coordArrayToken = parsed["features"].Children().First()["geometry"]["coordinates"];
var coordinates = coordArrayToken.ToObject<decimal[][]>();

Related

How to get key value from input json in C# [duplicate]

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JSON.NET JObject - how do I get value from this nested JSON structure
(1 answer)
JSon.NET deserialising subitems
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Closed 1 year ago.
i have a json in below format
{{
"encoding_version": 1,
"root": {
"_type": "dictionary",
"test1": 0,
"test2": 6593,
"test3": ".key.test",
"test4": "key.test",
"test5": ".key.14",
"test6": 6159
}
}}
i am trying to get "test5" value which is 14
var data = (JObject)JsonConvert.DeserializeObject(inputJson);
var id = data["test5"];
however getting it null,Please help.
You have provide JSON with two times curl braces, i have made this small correction in your input JSON :
{
"encoding_version": 1,
"root": {
"_type": "dictionary",
"test1": 0,
"test2": 6593,
"test3": ".key.test",
"test4": "key.test",
"test5": ".key.14",
"test6": 6159
}
}
As your deserialization is correct and you are looking for value of "test5" which is ".key.14". Your desired key is two level down in JSON i.e. first go for "root" and then "test5". Hence your code will look like:
string test5Value = (string)result["root"]["test5"];
output => .key.14
If you want 14 then you might need to split output string and take out the required value.

Deserialize a json object with an array [duplicate]

This question already has answers here:
Deserializing JSON Object Array with Json.net
(6 answers)
Deserialize JSON with C#
(10 answers)
Closed 6 years ago.
i have a json object that has a json array that i would love to deserialize
{
"status": 1,
"loans": [
{
"loan_id": "686",
"client_id": "269",
"client_name": "Byaruhanga Guard",
"total_amount": "10000",
"min_amount": "10000",
"start_date": "2016-07-28 13:12:30",
"duration": "2",
"payment_interval": "day",
"voucher": "92",
"description": "FUEL",
"when_added": "2016-07-28 13:12:30",
"approval_status": "approved",
"total_paid": null,
"next_payment_date": "2016-07-29 10:12:30"
}
]
}
please help.
use Newtonsoft.Json from NuGet package
var results= JsonConvert.DeserializeObject<string[]>(jsondata);
var loanjson=results["loans"];
var loandata= JsonConvert.DeserializeObject<string[]>(loanjson);

Json returned with space

I'm trying to check if In the json there is a certain property. Actually I can do it in the following way:
var container = (JContainer)JsonConvert.DeserializeObject(responseText);
var x = container.ToString(Formatting.None);
var message = container["text"];
now the variable responseText is returned as:
{[
{
"trace": {
"details": {
"data": "[29-02-2016 17:37:32.931751]",
"type": "[info]",
"text": "[Done.]"
},
"context": {
"context": [
[
{
"ID": "John Dillinger"
}
]
]
}
}
}
]}
in the x variable I have removed the space and the final result is:
"[{\"trace\":{\"details\":{\"data\":\"[29-02-2016 17:37:32.931751]\",\"type\":\"[info]\",\"text\":\"[Done.]\"},\"context\":{\"context\":[[{\"ID\":\"John Dillinger\"}]]}}}]"
Now if the key isn't found I get null:
if (message == null)
{
return responseText;
}
the problem is that I perform the condition on the message variable that check if in the container (not formatted) there is the property, the problem is that I get this exception:
{"Accessed JArray values with invalid key value: \"text\". Int32 array index expected."}
but if I replace container with the second json with the slash all working good. Now my problem is that I can't execute var message= x["text"]; 'cause x is a string. So how I can remove the space in the json and check if contain the text key?
It looks like when you removed the space, you also changed the order of the first brackets In the first example your first brackets are {[, in the second they are [{
In json, the ordering makes a difference. {} means object and [] means array.
[{"data":"value"}] is legal because you are saying that you have an array of an object. {["value"]} is not legal because your object does not have a name for the array. The legal version would be { "data":["value"] }
Here is a handy web tool to verify your JSON syntax

Deserializing JSON with Json.NET fails if internal string array exists

I am using Json.NET 6.x and I noticed weird behaviour:
If I want to deserialize this simple JSON, I get an error:
The code to deserialize:
object o = Newtonsoft.Json.JsonConvert.DeserializeObject(text);
and the JSON:
[
{
"Username": "tb386",
"TimestampUpdated": "2015-01-19T18:49:52.771571+01:00",
"AuthTokens": [
"Ua7JR5E7hSAxjafp6dpMrvw3HlICW3ZZdDuArMaU5ks="
]
}
]
The error I get is:
Unexpected character encountered while parsing value: U. Path '', line 0, position 0.
If I remove the array, it works fine. But all I have to do, is to remove the string inside the array, making it empty:
[
{
"Username": "tb386",
"TimestampUpdated": "2015-01-19T18:49:52.771571+01:00",
"AuthTokens": [ ]
}
]
and then it works fine. I should also note that the serialized JSON was produced by the Newtonsoft library, so the source is the same library!
If I try a validator (like http://jsonlint.com/) on the JSON with the array, it valides OK!
Can anyone help me out here?
Additional information: Even if I add a string inside VS and write the JSON hardcoded, it fails!
string text = "[ {\"Username\": \"tb386\",\"TimestampUpdated\": \"2015-01-19T18:49:52.771571+01:00\",\"AuthTokens\": [\"Ua7JR5E7hSAxjafp6dpMrvw3HlICW3ZZdDuArMaU5ks=\"] } ]";
object o = Newtonsoft.Json.JsonConvert.DeserializeObject(text);
Version info on Newtonsoft dll:

Unable to Parse this Json string in c#

I tried using Newtonsoft.Json to deserialize this json string, but I'm not getting the desired output.
my json string is
[
{
"id": 1,
"key": "Residential Homeowner",
"i18nText": "unknown message code DB_ENUM_UserType_residentialhomeowner",
"i18nKey": "DB_ENUM_UserType_residentialhomeowner"
},
{
"id": 8,
"key": "VAR Dealer \/ Builder",
"i18nText": "unknown message code DB_ENUM_UserType_vardealer\/builder",
"i18nKey": "DB_ENUM_UserType_vardealer\/builder"
},
{
"id": 2,
"key": "Administrator",
"i18nText": "unknown message code DB_ENUM_UserType_administrator",
"i18nKey": "DB_ENUM_UserType_administrator"
},
{
"id": 9998,
"key": "TempGuidUser",
"i18nText": "unknown message code DB_ENUM_UserType_tempguiduser",
"i18nKey": "DB_ENUM_UserType_tempguiduser"
},
{
"id": 9999,
"key": "GuidUser",
"i18nText": "unknown message code DB_ENUM_UserType_guiduser",
"i18nKey": "DB_ENUM_UserType_guiduser"
}
]
I just want the value of key when value of id=1. Generally json starts with {}(curly bracket) but here it is like [](square bracket). I've seen many examples but none worked for me.
Generally json starts with {} (curly bracket), but here it is like [] (square bracket).
This is because you got an array of objects, not a single object. Arrays are serialized with square brackets around them. You should deserialize it into an array, and then grab the object at the index of interest.
This is a related post that addresses JSON parsing in C#: C# JSON Parsing.
If the brackets are a problem, simply use:
string json = inputJson.Trim().Trim('[',']');
If the id can have a minimum value of 1, then this should work:
string GetKey(string inputJson)
{
string key = inputJson.Substring(inputJson.IndexOf("key")+5);
key = key.Substring(key.IndexOf("\""), key.IndexOf(",")-key.IndexOf("\""));
key = key.Trim('\"');
return key;
}
If you are only interested in a single value from that larger JSON value, you may want to try Linq to JSON which would allow you to query over the JSON without deserializing everything.
Example:
JArray values = JArray.Parse(json);
string key;
var keyObject = values.FirstOrDefault(p => (int)p["id"] == 1);
if (keyObject != null)
{
key = (string)keyObject["key"];
}
[] is to define a json object array. Your output should be an array. Traverse through the array like:
for(var i=0; i<output.Length; i++)
{
if(output[i].id == "1") // desired id
{
Console.WriteLine(output[i].key);// use it as you wish
}
}
and use the found objects key.

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