So I have a JSON string where I just want to read a specific value. How do I just pick "Read me please!" from string below?
var readString = /*Read me please!*/
JSON string:
"{\"aString\":\"Read me please!\"}"
For better understanding, how do I do the same here? (just "Read me please!"):
"{\"Result\":
{
\"aString\":\"Read me please!\",
\"anotherString\":\"Dont read me!\"
}
}"
If both alternative have different solution I would like to know both.
PS: I do not wish to save the value into object/class or so. Just temporary inside var readString.
You could write a model:
public class MyModel
{
public string AString { get; set; }
}
and then use a JSON serializer such as Json.NET:
string readString = "{\"aString\":\"Read me please!\"}";
MyModel model = JsonConvert.DeserializeObject<MyModel>(readString);
Console.WriteLine(model.AString);
If you don't want to use third party solutions you could use the built-in JavaScriptSerializer class:
string readString = "{\"aString\":\"Read me please!\"}";
MyModel model = new JavaScriptSerializer().Deserialize<MyModel>(readString);
Console.WriteLine(model.AString);
Now assuming you want to handle your second JSON string you could simply adapt your model:
public class Wrapper
{
public MyModel Result { get; set; }
}
public class MyModel
{
public string AString { get; set; }
public string AnotherString { get; set; }
}
and then deserialize to this wrapper class:
string readString = ... the JSON string in your second example ...;
Wrapper wrapper = JsonConvert.DeserializeObject<Wrapper>(readString);
Console.WriteLine(wrapper.Result.AString);
Console.WriteLine(wrapper.Result.AnotherString);
UPDATE:
And if you don't want to deserialize to a model you could directly do this:
string readString = "{\"aString\":\"Read me please!\"}";
var res = (JObject)JsonConvert.DeserializeObject(readString);
Console.WriteLine(res.Value<string>("aString"));
or with the built-in JavaScriptSerializer class:
string readString = "{\"aString\":\"Read me please!\"}";
var serializer = new JavaScriptSerializer();
var res = (IDictionary<string, object>)serializer.DeserializeObject(readString);
Console.WriteLine(res["aString"]);
var readString = JObject.Parse(str)["aString"];
Or for your second example:
var readString2 = JObject.Parse(str2)["Result"]["aString"];
Json.NET also provides a JSON reader if you don't want to deserialize the whole thing. For example:
string json = "{\"Result\": { \"aString\":\"Read me please!\", \"anotherString\":\"Dont read me!\" } }";
using (var reader = new JsonTextReader(new StringReader(json)))
{
while (reader.Read())
{
if (reader.TokenType == JsonToken.PropertyName && (string)reader.Value == "aString")
{
reader.Read();
Console.Write(reader.Value);
break;
}
}
}
Console.ReadKey();
You have to use Newtonsoft (JSON.NET) to accomplish that. Then, you can access your json property this way:
var obj = JsonConvert.DeserializeObject(yourJson);
Console.WriteLine(obj.Result.aString);
I played around with writing a generic method that can read any part of my json string. I tried a lot of the answers on this thread and it did not suit my need. So this is what I came up with. I use the following method in my service layer to read my configuration properties from the json string.
public T getValue<T>(string json,string jsonPropertyName)
{
var parsedResult= JObject.Parse(json);
return parsedResult.SelectToken(jsonPropertyName).ToObject<T>();
}
and this is how you would use it :
var result = service.getValue<List<string>>(json, "propertyName");
So you can use this to get specific properties within your json string and cast it to whatever you need it to be.
Related
So I have a JSON string where I just want to read a specific value. How do I just pick "Read me please!" from string below?
var readString = /*Read me please!*/
JSON string:
"{\"aString\":\"Read me please!\"}"
For better understanding, how do I do the same here? (just "Read me please!"):
"{\"Result\":
{
\"aString\":\"Read me please!\",
\"anotherString\":\"Dont read me!\"
}
}"
If both alternative have different solution I would like to know both.
PS: I do not wish to save the value into object/class or so. Just temporary inside var readString.
You could write a model:
public class MyModel
{
public string AString { get; set; }
}
and then use a JSON serializer such as Json.NET:
string readString = "{\"aString\":\"Read me please!\"}";
MyModel model = JsonConvert.DeserializeObject<MyModel>(readString);
Console.WriteLine(model.AString);
If you don't want to use third party solutions you could use the built-in JavaScriptSerializer class:
string readString = "{\"aString\":\"Read me please!\"}";
MyModel model = new JavaScriptSerializer().Deserialize<MyModel>(readString);
Console.WriteLine(model.AString);
Now assuming you want to handle your second JSON string you could simply adapt your model:
public class Wrapper
{
public MyModel Result { get; set; }
}
public class MyModel
{
public string AString { get; set; }
public string AnotherString { get; set; }
}
and then deserialize to this wrapper class:
string readString = ... the JSON string in your second example ...;
Wrapper wrapper = JsonConvert.DeserializeObject<Wrapper>(readString);
Console.WriteLine(wrapper.Result.AString);
Console.WriteLine(wrapper.Result.AnotherString);
UPDATE:
And if you don't want to deserialize to a model you could directly do this:
string readString = "{\"aString\":\"Read me please!\"}";
var res = (JObject)JsonConvert.DeserializeObject(readString);
Console.WriteLine(res.Value<string>("aString"));
or with the built-in JavaScriptSerializer class:
string readString = "{\"aString\":\"Read me please!\"}";
var serializer = new JavaScriptSerializer();
var res = (IDictionary<string, object>)serializer.DeserializeObject(readString);
Console.WriteLine(res["aString"]);
var readString = JObject.Parse(str)["aString"];
Or for your second example:
var readString2 = JObject.Parse(str2)["Result"]["aString"];
Json.NET also provides a JSON reader if you don't want to deserialize the whole thing. For example:
string json = "{\"Result\": { \"aString\":\"Read me please!\", \"anotherString\":\"Dont read me!\" } }";
using (var reader = new JsonTextReader(new StringReader(json)))
{
while (reader.Read())
{
if (reader.TokenType == JsonToken.PropertyName && (string)reader.Value == "aString")
{
reader.Read();
Console.Write(reader.Value);
break;
}
}
}
Console.ReadKey();
You have to use Newtonsoft (JSON.NET) to accomplish that. Then, you can access your json property this way:
var obj = JsonConvert.DeserializeObject(yourJson);
Console.WriteLine(obj.Result.aString);
I played around with writing a generic method that can read any part of my json string. I tried a lot of the answers on this thread and it did not suit my need. So this is what I came up with. I use the following method in my service layer to read my configuration properties from the json string.
public T getValue<T>(string json,string jsonPropertyName)
{
var parsedResult= JObject.Parse(json);
return parsedResult.SelectToken(jsonPropertyName).ToObject<T>();
}
and this is how you would use it :
var result = service.getValue<List<string>>(json, "propertyName");
So you can use this to get specific properties within your json string and cast it to whatever you need it to be.
so i want to get bitcoin price from a URL and see it in a label in my form.
URL
i tried to make a class for it with the code
public string price { get; set; }
but i don't know what to do after that, i searched a lot in google but they all show the result in list and etc
To deserialize, first you need to make a class with the attributes the JSON has. This page will help you a lot in that.
Once you have a class, you need to deserialize your JSON into that class. In C# I like to use JsonConvert from the library Newtonsoft.Json, you need to import it.
The method that deserializes it is JsonConvert.DeserializeObject.
One little example, let's say your class is called Bitcoin, then you would have to do it that way :
var myBitcoin = JsonConvert.DeserializeObject<Bitcoin>(yourJson);
EDIT: To pull your json from an URL you can use Webclient DownloadString method.
var myjson = new WebClient().DownloadString("url");
This post may also help you.
This should be your class.
public class APIResponse
{
public string symbol { get; set; }
public string price { get; set; }
}
Then in your function add these lines.
APIResponse response = new APIResponse();
response = JsonConvert.DeserializeObject<APIResponse>();
myPriceLabel.Text = response.price;
What did we do? We created a C# model same as the Json Data model and we took JSON data and converted it to APIResponse type so we can access it and use it as we like.
It can be achieved simply by converting the Json with generic object
var myBitcoin = JsonConvert.DeserializeObject<object>(yourJson);
thank you all for answering but i found the solution!
the code should be like this
string url = "https://api.binance.com/api/v3/ticker/price?symbol=BTCUSDT";
using (WebClient wc = new WebClient())
{
var json = wc.DownloadString(url);
JavaScriptSerializer oJS = new JavaScriptSerializer();
PriceClass obj = new PriceClass();
obj = oJS.Deserialize<PriceClass>(json);
BTCPrice_Label.Text = obj.price;
}
and the class should be like this
using System;
public class PriceClass
{
public string symbol { get; set; }
public string price { get; set; }
}
I want to write a PowerShell function in C#. During the process I receive a string with JSON content.
My sample json content is:
string json = "{'TestNr':{'Name':'CSHARP', 'Description':'Test Descriptiopn'}}"
This string should be converted to a PSObject just like ConvertFrom-Json would do.
I was trying to create an object with below lines. It works but it would require a lot of manual scripting especially if the JSON string becomes longer.
PSObject obj = new PSObject();
obj.Properties.Add(new PSNoteProperty("Head", "Children"));
I tried also the below line:
obj = (PSObject)TypeDescriptor.GetConverter(typeof(PSObject)).ConvertFromString(json);
For this I get however the error (I run the function in PowerShell 7):
TypeConverter cannot convert from System.String.
There are two ways you can parse the string in C# that would be the easiest to go with.
public class MyClass
{
public TestNRClass TestNR { get; set; }
}
public class TestNRClass
{
public string Name { get; set; }
public string Description { get; set; }
}
// In the main,
string json = #"{""TestNr"":{""Name"":""CSHARP"", ""Description"":""Test Descriptiopn""}}";
MyClass jobj = JsonConvert.DeserializeObject<MyClass>(json);
Console.WriteLine(jobj.TestNR.Name);
This is with the strong typed class object. This is what you should be using in C#.
Other way is to get an object
string json = #"{""TestNr"":{""Name"":""CSHARP"", ""Description"":""Test Descriptiopn""}}";
JObject obj = JObject.Parse(json);
Console.WriteLine(obj.ToString());
Console.WriteLine(obj["TestNr"]["Name"].ToString());
// You can also add more keyValuePair
obj["NewVariable"] = "stest";
Console.WriteLine(obj.ToString()); // Shows the new item as well.
My Json is
{
Id: 1,
Name:'Alex',
ConnectedObjectName:'Obj',
ConnectedObjectId: 99
}
I want this JSON to be converted to the following object
Class Response
{
int Id,
string Name,
ConnectedObject Obj
}
Class ConnectedObject
{
string COName,
int COId
}
Is there a way to achieve this using DataContractJsonSerializer
Most serializers want the object and the data to share a layout - so most json serializers would want ConnectedObjectName and ConnectedObjectId to exist on the root object, not an inner object. Usually, if the data isn't a good "fit" for what you want to map it into, the best approach is to use a separate DTO model that matches the data and the serializer, then map from the DTO model to the actual model you want programatically, or using a tool like auto-mapper.
If you used the DTO approach, just about any JSON deserializer would be fine here. Json.NET is a good default. DataContractJsonSerializer would be way way down on my list of JSONserializers to consider.
To expand on what Marc Gravell has said, most JSON serializers would expect your JSON to look like the following, which would map correctly to your classes:
{
"Id": 1,
"Name": "Alex",
"Obj" : {
"COName": "Obj",
"COId": 99
}
}
The way to get around this would be to read your JSON into an object that matches it, and then map it form that object to the object that you want:
Deserialize to this object:
class COJson {
public int Id;
public string Name;
public string ConnectedObjectName;
public int ConnectedObjectId;
}
Then map to this object:
class Response {
public int Id;
public string Name;
public ConnectedObject Obj;
}
class ConnectedObject {
public string COName;
public string COId;
}
Like this:
using(var stream = new MemoryStream(Encoding.Unicode.GetBytes(json)))
{
var serializer = new DataContractJsonSerializer(typeof(COJson));
var jsonDto = (COJson)ser.ReadObject(stream);
var dto = new Response(){
Id = jsonDto.Id,
Name = jsonDto.Name,
Obj = new ConnectedObject(){
COName = jsonDto.ConnectedObjectName,
COId = jsonDto.ConnectedObjectId
}
};
return dto;
}
I am taking an HttpRequest and reading it to a string
var body = request.Content.ReadAsStringAsync().Result;
This body gives me a string that looks like the following:
"To=Jim&From=Dan+Bailey"
I want to serialize body to aumatically bind to an object that looks like
public class Letter
{
[JsonProperty("To")]
public string To { get; set; }
[JsonProperty("From")]
public string From { get; set; }
}
Any ideas? I tried using JsonSerializer and Newtonsoft.Json.Convert but both require a different format
Json deserializers would only work on Json strings
You may convert the querystring to a NameValueCollection directly using the utility ParseQueryString
var body = request.Content.ReadAsStringAsync().Result;
var parameters = HttpUtility.ParseQueryString(body);
For most purposes, using a NameValueCollection should suffice, but if you still need a strongly-typed object, I would suggest using either reflection, or first serialize to a json string then use Newtonsoft deserializer
var dict = new Dictionary<string, string>();
foreach (var key in parameters.Keys)
{
dict.Add(key, parameters[key]);
}
var json = JsonConvert.SerializeObject(dict);
var obj = JsonConvert.DeserializeObject<Letter>(json);
What you have is not a JSON but most likely a simple html parameter string. Looks like the format is fixed given how your class Letter looks like.
I guess you can just do it with Regex :
var match = Regex.Match("To=Jim&From=Dan+Bailey", "To=(?<To>[^&]+)&From=(?<From>[^&]+)");
var letter = new Letter() { To = match.Groups["To"].Value, From = match.Groups["From"].Value };