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POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
 

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  1. POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
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    <p>I am deserializing a JSON result as follows:</p> <pre><code>responsebody = WebClient.DownloadString(URI); Console.WriteLine(responsebody); if (string.IsNullOrEmpty(responsebody)) { throw new Exception("The request returned empty Position Object."); } if (responsebody.Length &gt; 0) { //dynamic dynObj = JsonConvert.DeserializeObject(responsebody); //if (dynObj.positions == null) //{ // throw new Exception("The request returned empty Position Object."); //} RootPositions PosList = JsonConvert.DeserializeObject&lt;RootPositions&gt;(responsebody); if (PosList.positions.position.Count() &gt; 1) foreach (var p in PosList.positions.position) { Console.WriteLine("Id : {0}", p.id); Console.WriteLine("Symbol : {0}", p.symbol); Console.WriteLine("Quantity : {0}", p.quantity); Console.WriteLine("Average Price : {0}", p.cost_basis); } } return responsebody; </code></pre> <p>The class for the above deserialization is as follows:</p> <pre><code>//******** JSON Object to PositionData Class public class RootPositions { public PositionList positions { get; set; } } public class PositionList { //[JsonConverter(typeof(GenericListCreationJsonConverter&lt;Position&gt;))] public List&lt;Position&gt; position { get; set; } } public class Position { public float cost_basis { get; set; } public int id { get; set; } public decimal quantity { get; set; } public string symbol { get; set; } } </code></pre> <p>My code doesnt work the way I am handling if I get a NULL JSON result as below.</p> <p>JSON returned: <code>"{\"positions\":\"null\"}"</code> or {"positions":"null"}</p> <pre><code>Newtonsoft.Json.JsonSerializationException: {"Error converting value \"null\" to type 'ApiPost.PositionList'. Path 'positions', line 1, position 19."} System.ArgumentException: Could not cast or convert from System.String to ApiAddIn.PositionList. </code></pre> <p>How can I check for NULL and also how can I check if the JSON is giving back a Position List or only 1 position. Greatly appreciate your help.</p>
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    1. USaceventura
    1. USaceventura
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      1. POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
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      1. POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
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    1. COAre you sure you are getting `"{\"positions\":\"null\"}"` and not `"{\"positions\": null}"` (no quotes around null) ?
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      1. POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
      1. USMauro Cerutti
    2. COI'm sorry for the Output format. This is what I intended: `{"positions":"null"}`
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      1. POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
      1. USaceventura
    3. COThat's seems like a problem: with quotes around null, it means then `position` property is a string. If `null` was not quoted, you deserialization code would be correct. Do you generate/control that JSON response?
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      1. POHow to check for NULL or a single object in a list returned by JSON deserialization using Newtonsoft JSON.NET in C#
      1. USMauro Cerutti
 

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